The Glossary # - Z

[B]A work in progress.

This Glossary is a concise collection of some of the terminology that you may confront; it is not intended to be a complete compendium of technical terms.[/B]


3D Glasses - Types And How They Work. (Brief Summary)

There are different modes of implementing the 3-D Technology.

The Glasses
The Montior Itself
Active Components

Anaglyph Glasses

One of the first types of consumer 3D glasses were the old red and blue ones.They worked somewhere between bad and really bad, were monochrome and had a lot of ghosting.

When viewing with these glasses each eye is seeing a slightly different picture. The eye covered by the red filter sees the red parts of the image as “white”, and the blue parts as “black” (with the brain providing some adaption for color); the eye covered by the blue filter perceives the opposite effect. True white or true black areas are perceived the same by each eye. The brain blends together the image it receives from each eye, and interprets the differences as being the result of different distances. This creates a normal stereograph image without requiring the viewer to cross his or her eyes.

Polarised Glasses

This is the most common version with each eye being polarised at 45 degrees to each other or circularly in opposite directions. They work pretty well, but usually require two projectors in a theatre or a few additional layers in a monitor. This adds cost, sometimes a lot, but it is a one time event, and the glasses cost marginally more than anaglyph glasses.

These 3D glasses create the illusion of three-dimensional images by restricting the light that reaches each eye. As each filter passes only that light which is similarly polarized and blocks the light polarized in the opposite direction, each eye sees a different image. This is used to produce a three-dimensional effect by projecting the same scene into both eyes, but depicted from slightly different perspectives. Since no head tracking is involved, several people can view the stereoscopic images at the same time.

Active Shutter Glasses

These are basically glasses that have LCDs in each eye, and turn black every other frame.They also work pretty well, but you get half the frames in one eye, and half the frames in the other. This can lead to headaches as your eyes try to compensate for the on/off light, low frame rates for gamers and synch problems.

Active shutter glasses need a transmitter that is synced to the frame rate, usually through an IR transmitter. If you are out of range, turn your head, or have any obstructions, it may stutter or simply not work. Worse yet, they are battery operated, so you have to replace batteries or charge them, and in general spend time and effort keeping them working. The cost of active shutter glasses is many times that of passive glasses. Everybody needs a set to watch and it can get costly.

3D Screens

There are several technologies used to do this but they have two traits in common. First is that they use multiple screen layers like the polarised glasses, adding to cost, but you don’t need glasses. The drawback is that they have a very narrow viewing angle, so the sweet spot is generally good for only one person.

Dolby 3D Digital Cinema

Not applicable to PC monitiors because they don’t work in a compatible way right now. This is far best the mode for watching 3D. It slices up light into spectrum bands, and each eye gets half of the colours. There are about 50 bands, so you don’t see anything other than a very clear and clean picture.


480i is the shorthand name for a video mode. The i, which is sometimes uppercase, stands for interlaced, the 480 for a vertical frame resolution of 480 lines. The digitally transmitted horizontal resolution is usually 720 or 704 pixels with an aspect ratio of 4:3 and therefore a display resolution of 640 × 480 (VGA); that is standard-definition television (SDTV).

The field rate (not the frame rate) is usually (60/1.001) 59.94 hertz for color TV and can be rounded up to 60 Hz. There are several conventions for written shorthands for the combination of resolution and rate: 480i60, 480i/60 (EBU) and 480/60i. 480i is usually used in countries that conventionally use NTSC (North America, Japan), because the 525 transmitted lines at 60 hertz of analogue NTSC contain 480 visible ones. 480i can be transported by all major digital television formats, ATSC, DVB and ISDB. NTSC DVDs use 480i when high motion is desired, but for movies 24 progressive frames per second (480p) are used instead. The 480i resolution is used in most standard-definition TVs.


480p is the shorthand name for a video display resolution. The p stands for progressive scan, i.e. non-interlaced, while the 480 denotes a vertical resolution of 480 vertical scanning lines, usually with a horizontal resolution of 640 pixels and 4:3 aspect ratio on standard-definition television (SDTV), or a horizontal resolution of 854 pixels and 16:9 aspect ratio on high-definition television (HDTV). 480p is not high enough to qualify as HDTV; it is considered Enhanced-definition television (EDTV). The frame rate is usually 30 or 60 hertz and can be given explicitly after the letter.


720i is a non-standard term applied to HDTV Broadcast. Like 720p, it features a resolution of 1280x720 pixels, however, it instead produces an interlaced image as opposed to a progressive image. This is similar in manner to how 1080i is 1920x1080 pixels, but interlaced as opposed to 1080p which is progressive.

The most common practical usage of 720i is that by Satellite broadcasters. Echostar/DISH Network is transmitting some HDTV channels in the interlaced format consisting of 720 lines as a bandwidth saving measure. The 720i format is then converted to the receiver’s selected output resolution (720p or 1080i) for presentation to the display.


720p is the shorthand name for a category of HDTV video modes. The number 720 stands for 720 lines of vertical display resolution, while the letter p stands for progressive scan or non-interlaced. When broadcast at 60 frames per second, 720p features the highest temporal (motion) resolution possible under the ATSC standard. Progressive scanning reduces the need to prevent flicker by filtering out fine details, so spatial (sharpness) resolution is much closer to 1080i than the number of scan lines would suggest.

720p assumes a widescreen aspect ratio of 16:9, and a horizontal resolution of 1280 pixels for a total of about 0.92 million pixels. The frame rate (in this case equal to the field rate) can be either implied by the context or specified in hertz after the letter p. The five 720p frame rates in common use are 24, 25, 30, 50 and 60 Hz (or fps).


1080i is a shorthand name for a category of video modes. The number 1080 stands for 1080 lines of vertical resolution, while the letter i stands for interlaced or non-progressive scan. 1080i is a high-definition television (HDTV) video mode. The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels and a frame resolution of 1920 × 1080 or about 2.07 million pixels. The frame rate in hertz can be either implied by the context or specified after the letter i. The two frame rates in common use are 25 and 30 Hz, with the former (1080i25) generally being used in traditional PAL and SECAM countries (Europe, Australia, much of Asia, Africa), and the latter (1080i30) being used in traditional NTSC countries (e.g. United States, Canada and Japan).


1080p is the shorthand name for a category of display resolutions. The number “1080” represents 1,080 lines of vertical resolution, while the letter p stands for progressive scan (meaning the image is not interlaced). 1080p is considered an HDTV video mode. The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels. This creates a frame resolution of 1920×1080, or 2,073,600 pixels in total. The frame rate in Hertz can be either implied by the context or specified after the letter p, such as 1080p30, meaning 30 Hz.


Standard “square” NTSC TV screen-size aspect ratio of 4 arbitrary units wide by 3 arbitrary units high; often expressed as 4x3 or 4 by 3. It was originally known as the Academy Ratio (as in Academy of Motion Picture Arts and Sciences, the film industry organization that awards the Oscars) prior to 1954 and the introduction of wide-screen aspect-ratio film formats; also known in the film world as 1.33:1.


16:9 (generally named as: “Sixteen-by-Nine”) is the international standard format of HDTV as used in Australia, Canada, Japan, South Korea, and the United States, as well as in Europe on HDTV and non-HD widescreen television (EDTV) PALplus. Japan’s Hi-Vision originally started with a 5:3 ratio but converted when the international standards group introduced a wider ratio of 5 1/3 to 3 (16:9), invented by Kerns H. Powers in the 1984. The 1.78:1 aspect ratio was the compromise between the 35 mm US and UK widescreen standard (1.85:1) and the 35 mm European widescreen standard (1.66:1)

2:2 pull-down

Method for transferring 24 frame-per-second film to PAL/SECAM video running at 25 frames per second.

2:3 pull-down detection

Also (and less accurately) called 3:2 pull-down; digital technology developed by Faroudja to accurately convert and display content originally on celluloid film, which runs at 24 frames per second (fps) compared to the 30fps rate of television. It is found in many DVD players and DTVs.


2K is a term, like SD and HD, used in today’s post-production environment to describe a particular image size and quality of data. 2K data exceeds our pre-existing television broadcast standards for both SD and HD and is therefore most commonly associated with traditional cinema and the emerging digital cinema initiative. When working with data for eventual cinematic projection, FX work or digital intermediate purposes, 2K is usually defined as 2048x1556 pixels. This size represents the “full” size of the 35mm film between the sprockets. Therefore the result, 2048x1556 pixels, appears as a 4x3 image when compared to an HD image which is typically 16x9. In 2K, other image sizes can be derived from this 2048x1556 source by taking a cropped portion of the image for use. For a traditional cinematic projection scenario, the final delivery of this 2048x1556 data is onto 35mm film. The film undergoes photochemical and mechanical processes before the image reaches the screen. The other common size attributed to 2K is 2048x1080; this is the standard to which digital cinema currently adheres. Most digital cinema projectors have this 2048x1080 image size as a supported resolution and in many cases, as a maximum resolution. Here the data at 2048x1080 need not undergo a photochemical process; it can stay data for its path to projection.


Usually defined as 4096 x 4097, However, the vertical resolution of the K’s can vary by quite a bit. A 4K scan of the entire 35mm film frame will be 4096x3112. A 4K image for a 1.85:1 output will be 4096x2214. A 4K 2.39:1 output could be 4096x3112 or 4096x1714 depending on whether it is anamorphic or not. To simplify things just remember this, 4K has four times the number of pixels as 2K for the same aspect ratio. 2K has 13% more pixels than HD. In all other areas, such as bit depth and color format, 4K, 2K, and HD RGB are identical. 4K has many advantages, and may someday become the standard for digital intermediate work, but with today’s technology the costs of working in 4K often exceed the benefits.


5.1 is a surround sound setup that consists of five speakers that emit five audio channels–center, right, left, and surround sound right and left–and one subwoofer speaker that emits a low-frequency sound.


6.1 is a surround sound setup that consists of six speakers that emit six audio channels–center, right, left, and surround sound right and left, and rear–and one subwoofer speaker that emits a low-frequency sound.


7.1 is a surround sound setup that consists of seven speakers which emit seven audio channels–center, right, left, and surround sound right and left, and two in the rear–and one subwoofer speaker that emits a low-frequency sound.


5 company Digital Transmission Content Protection. An HDTV copy-protection encryption method for devices connected via FireWire, this allows one of three copy states: copy always (all ATSC broadcast and “in the clear” QAM cable broadcasts); copy once (premium cable); and, copy never (pay per view, video-on-demand). Bidirectional system requires 5C chips in every device in an A/V system (in other words, a set-top box, a TV, and so on); the TV “requests” acknowledgment before allowing the signal to be viewed or recorded. Proposed and sponsored by Hitachi, Intel, Matsushita (Panasonic), Sony, and Toshiba–the five companies.


A data encryption standard. As its name suggests, 3DES is a three-step data encryption algorithm that evolved from DES. 3DES provides greater security than DES because it encrypts, decrypts, and encrypts the data using three keys instead of just one. The size of a 3DES key is also three times bigger: 168 bits to 56 bits for DES.



Measurement based roughly on the uneven frequency sensitivity of the human ear. The influences of low and high frequencies are reduced in comparison to midrange frequencies because people are most sensitive to midrange sounds.


Advanced Access Content System, the content protection system used by BD-ROM.

Absolute Polarity

A recording with correct absolute polarity played back through a system with correct absolute polarity will produce a positive pressure wave from the loudspeakers in response to a positive pressure wave at the original acoustic event. Incorrect absolute polarity introduces a 180 phase reversal of both channels. Absolute polarity is audible with some instruments and to some listeners.


The 5.1-channel sound system specified in the Standard for Digital-HDTV. Also known as “Dolby Digital,” AC-3 delivers CD-quality digital audio and provides five full-bandwidth channels for front left, front right, center, surround left and surround right speakers, plus an LFE (low frequency effect) subwoofer, for a total of 5.1 channels.

AC line-conditioner/protector

A device that filters noise from the AC power line and isolates equipment from voltage spikes and surges. Some AC line-conditioners/protectors also protect equipment from lightning strokes. Home-theater equipment is plugged into the AC line-conditioner/protector, and the conditioner is plugged into the wall.

Academy Curve

An intentional roll-off in a theatrical system’s playback response above ~2kHz (to -18dB at 8kHz) to minimize noise in mono optical tracks. Some (many) transfers to home video of mono movies have neglected to add the Academy filter during transfer, giving many old movies a screechy sound they were never intended to have. A few home processors have an Academy filter option, making them a must for old-movie buffs. Has been used since 1938.


Advisory Committee on Advanced Television Service; special FCC committee that recommended DTV standards in 1997.

Acoustic Absorber

Any material that absorbs sound, such as carpet, drapes, and thickly upholstered furniture.

Acoustic Diffuser

Any material that scatters sound.

Acoustic Panel Absorber

A device that absorbs low to mid frequencies by diaphragmatic action. That is, sound striking the panel absorber causes the panel to move, converting acoustic energy into a minute amount of heat in the panel.

Acoustic Suspension

A sealed speaker enclosure that uses the air trapped in the cabinet as a reinforcing spring to help control the motion of the woofer(s).


The science of sound behavior.

Acoustically Transparent Screen

This screen is used when speakers are place directly behind the screen. Material that does not have acoustical transparency will block the sound wave and create a distortion in the audio.

Active Format Description

(AFD) is a signal that broadcasters can transmit with the picture to enable both 4:3 and 16:9 television sets to optimally present pictures transmitted in either format. Essentially, AFD is a standard set of codes sent in the MPEG video stream that provides information to the decoder about where in the coded picture the active video is. They can then use this information, together with knowledge of the display shape and user preferences, to choose a presentation mode.

Active Subwoofer

A speaker designed to reproduce only low frequencies, and which includes an integral power amplifier to drive the speaker.

Advanced Content

One of two HD DVD specifications defined by the DVD Forum. Advanced Content enables a majority of the new capabilities in the HD DVD format.


The Advanced Encryption Standard is a data encryption scheme that trumps DES and even 3DES by using three different key sizes (128-bit, 192-bit, and 256-bit) but only one encryption step to encrypt data in 128-bit blocks. Based upon the Rijndael (pronounced “rain doll” or “Rhine Dahl”) algorithm created by Joan Daemen and Vincent Rijmen of Belgium, AES was adopted by the U.S. government in 2002 as the encryption standard for protecting sensitive but unclassified electronic data. With the arrival of AES, the United States officially phased out DES except for in legacy systems, but as of this writing, 3DES is still an acceptable alternative.

Advanced Television Systems Committee (ATSC)

The ATSC is the committee responsible for developing and establishing Digital-HDTV Standards; as well as all (18) formats of Digital TV.


Analog to digital conversion (or converter). Used at transmission end of broadcast.

Addressable Resolution

The highest resolution signal that a display device (TV or monitor) can accept. Caution: Consumers should be aware however, that although a particular device (Digital-HDTV) is able to receive the resolution, it may not be capable of displaying it.

After Color Temp

It is the color temperature at a given brightness level after grayscale calibration. Usually expressed in degrees Kelvin ideally as close to 6,500K as possible.

After Grayscale Variation

After calibration, the average amount of variation from an ideal of 6,500K, measured over the entire range of the grayscale–typically 20 to 100 IRE in 10-IRE increments.


Sonic description of bass that can follow quicidy changing pitches and dynamics.


Spatial aspects of a film soundtrack that create a sense of size and atmosphere, usually reproduced by the surround speakers.

Analog Hole

A movie industry term for the potential to create high quality copies of copy protected digital content by digitizing the analog output that is unprotected. Digital streams can be copy protected using encryption whereas analog signals cannot.

Anamorphic Widescreen

Adopted from the film technique of shooting a wide-screen image on a square 35mm frame, it’s the process of compressing wide-screen images to fit into the squarer standard 4:3 television signal. The images are then expanded for viewing in their original format on a wide-screen display device. Wide-screen or letterboxed DVDs that are not anamorphic have less detail when projected on a wide-screen monitor. In other words, a nonanamorphic wide-screen DVD is designed to be shown letterboxed on a standard “square” TV but appears with a black box all around the image when shown on a larger 16:9 wide-screen TV. To fill a 16:9 screen, a nonanamorphic DVD has to be blown up, resulting in loss of resolution and detail. Conversely, a DVD that is anamorphic, enhanced for 16:9, or enhanced for wide-screen delivers 33 percent more resolution than regular letterboxed transfers, is designed to be shown on a 16:9 TV, and does not need to be blown up. When one of these DVDs is shown on a “square” TV, it is often subject to anamorphic down conversion artifacts unless the TV has a vertical compression feature.

ANSI Lumens

Light-output specification set in 1993 used mainly to measure brightness of front-projection televisions; more exact than undefined lumens. The average 7-inch, CRT front-projection television is capable of between 150 and 175 ANSI lumens, while 9-inch CRT sets emit between 200 and 240. DLP and LCD projectors range from 600 to 7,000, depending on the model.


A device that controls amount of light admitted.

Aperture Correction

Compensation for the loss in sharpness of detail because of the finite dimensions of the image elements or the dot-pitch of the monitor.


Sonic description of a component that clearly resolves pitches.


Unwanted visible effects in the picture created by disturbances in the transmission or image processing, such as ‘edge crawl’ or ‘hanging dots’ in analog pictures, or ‘pixilation’ in digital pictures.

Aspect Ratio

Aspect ratios are mathematically expressed as x:y. The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1. Two common video graphic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently.

Academy - 1.33:1 (current) or 1.37:1 (before a soundtrack is added)

The Academy ratio (1.37:1 before a soundtrack was incorporated onto the film) was the primary original aspect ratio. Most movies (if not all) that were released before The Robe (the first movie to be shown in widescreen) were shown in this ratio.

When televisions first came on the scene, they were (and still are) designed with an aspect ratio matching the Academy ratio so that movies would be shown in the same way as in the theatres. Movies that were filmed in an Academy ratio will not have a “widescreen” version because they fit perfectly on the TV. Such movies include The Wizard of Oz, Casablanca, Citizen Kane, and many, many others.

Cinemascope - 2.35:1 to 2.55:1

This was once the most commonly used method of filming movies because its only major requirement was a special CinemaScope projector lens. This lens was and still is available at many movie theatres. CinemaScope was originally created by 20th Century Fox, but it is no longer in use in its original format.

The 2.55:1 ratio was pretty much dead by 1957 when the last holdout, Fox, adopted magoptical over mag-only prints. From that point until the early 1970s a standard of 2.35:1 was used; however, there is usually slight matting in theatres which results in a theatrical aspect ratio closer to 2.40:1. All of the Star Wars movies and even the 1997 animated version of Anastasia were filmed in CinemaScope, as were classics like The Robe and 20,000 Leagues Under the Sea.

Cinerama - 2.35:1 when transferred, 2.60:1 originally

This method of filming actually used three cameras, after which the three images were interlocked together. This created an extremely wide presentation of up to 2.60:1. However, any transfer to video would be from a 35mm anamorphic reduction print. Therefore, home video transfers have a 2.35:1 ratio. Several movies were filmed in Cinerama, including How the West Was Won, The Wonderful World of The Brothers Grimm, and Seven Wonders of the World.

Cinerama also required the screen onto which the image was projected to be deeply curved or else the resulting picture would suffer from severe distortions as a result of projecting at different angles. (This is the “trapezoid” effect that you get when a projector is not at an exact angle to the screen.) Therefore, it is not really possible to make a “widescreen” version of a Cinerama film suitable for viewing on a television unless some form of corrections are applied to eliminate the distortion.

Hard Matte / Open Matte - 1.66:1 to 1.85:1

Both hard and soft matting involves filming a movie onto a 1.33:1 frame and matting the frame during post-production to get its intended aspect ratio. The main difference between the two is how the movie is processed for home viewing.

Most open matte films have the mattes removed when transfered to a “full frame” home video release. This can dramatically increase the potential for unexpected material such as boom mikes to appear in the home video version. In fact, some directors simply placed cardboard on the monitors to simulate the matted theatrical version. This would have made them unaware during filming if the boom mikes and so forth were actually on the frame because the cardboard was blocking that part out.

Hard matted films are “locked” to their aspect ratio and are subjected to the pan-and-scan process for the “full frame” home video release. This results in the loss of visual information on the sides of the frame. Movies such as Memphis Belle are hard matted.

Panavision - 2.40:1 (anamorphic) / Various (flat)

The Panavision company is now the most successful maker and distributor of lenses and filming equipment. In the 1970s their Panavision lenses became the “standard” for widescreen and non-widescreen movies. Panavision still makes or sells the lenses for most of the major studio productions today, including lenses for films made with matting as opposed to true widescreen. These matted films are not necessarily 2.40:1, but are most likely 1.85:1.

Because Panavision now represents the manufacturer and distributor more than the filming process, it is not uncommon to see that many television shows are filmed with Panavision lenses. Therefore, it is important to note that “Filmed with Panavision cameras and lenses” does not automatically constitute a widescreen process.

Super 35 - Various

This process does not involve widescreen lenses, but rather it involves framing the picture to fit the ratio of the screen. The top and bottom of the frame are “matted” out and removed from the picture completely, resulting in a rectangular picture.

Super35 movies are filmed using flat lenses. Using an optical printer, the “interpositive” image is then contact-printed to produce an “internegative” anamorphic release print. As a result, an anamorphic image from a Super35 original tends to have a “gritty but sharp” look that is “harder” in a way than an anamorphic image, which has a “smooth” look.

Many movies made in Super35 are transferred to video with the top and bottom of the frame restored, so that you actually see more of the picture on video than you did in the theater. However, scenes which include special effects in them are almost always filmed hard-matted in the appropriate widescreen ratio and therefore must be subjected to the pan-and-scan process.

Super Panavision - 2.20:1

Super Panavision 70 was a 70mm version of the Panavision process meant to compete directly with the 70mm Todd-AO process. Super Panavision 70 has also been known as Panavision 70, Super Panavision, Panavision, and Panavision Super 70. With an anamorphic lens, SP70 movies could have a final aspect ratio of 2.76:1. Famous movies that were filmed in Super Panavision 70 are My Fair Lady, 2001: A Space Odyssey, and Chitty Chitty Bang Bang.

Technirama - 2.20:1 (70mm) / 2.35:1 (35mm)

This process was developed by the Technicolor Corporation, as a way to continue using its three-strip Technicolor cameras. It required both a specially developed camera to run the film sideways (like VistaVision) with a widescreen lens (like CinemaScope).

Technirama was shot with VistaVision cameras and an anamorphic lens squeezing the image by 25%. The entire 1.5:1 image area was then either optically unsqueezed to 70mm yielding a 2.21:1 aspect ratio, or given an additional squeeze to 35mm 2.35:1 4-perforated (four sprocket holes per frame) Panavision. For purposes of video transfer only an A/R of 2.35:1 would apply since there was never a 65/70mm negative involved in the process.

Todd-AO - 2.20:1 (during filming) / 2.35:1 (final 35mm print)

This process uses a 65mm negative printed onto 70mm film, with a six-track soundtrack, producing a very high quality picture. The original filming was done in an aspect ratio of 2.2:1; however, during the printing to 70mm film, the aspect ratio ended up being closer to a 2.35:1 aspect ratio. The original Todd-AO format also was shot at 30 frames per second, as opposed to the current standard of 24 frames per second.

Many of the great epics and musicals of the 50s and 60s used this format.

Ultra Panavision 70 - 2.76:1 (65/70mm) / 2.35:1 (35mm)

Ultra Panavision 70, created by MGM, was created to compensate a shortcoming with the original CinemaScope format called “CinemaScope mumps” where close-up images in the center of the screen did not get compressed properly. UP70 used anamorphic lenses and a consistent frame rate of 24 frames per second, which was not yet a standard among the various film formats. This was done with a camera that MGM called the “MGM Camera 65”.

UP70 was used to film some of the most popular movies in movie history, like Ben Hur, Mutiny on the Bounty, and It’s a Mad, Mad, Mad, Mad World.

VistaVision - 1.66:1 / 1.85:1 / 2.0:1

This system was more flexible than others, allowing for more aspect ratios. But Paramount’s specs always referenced a preferred A/R of 1.85:1. All VV prints were hard matted to around 1.66:1 to allow some flexibility in framing.

VistaVision movies were filmed with a specially designed camera that was mounted on its side. This special filming method required a special projector, but its image quality was better than standard 35mm.

Movies that are shot in VistaVision were photographed on a double-width frame of 35mm running right to left horizontally. The films were generally “reduction printed” to 35mm 4-perforated (four sprocket holes per frame) in dye-transfer Technicolor and projected with a 1.85:1 ratio. The image area was extracted optically from the full frame. For some special venues the double-frame 35mm film was cropped to 1.85:1 during projection. VistaVision movies include Vertigo, North By Northwest, and White Christmas.


To turn down, reduce, decrease the level of; the opposite of boost.


“Advanced Television” is an earlier term used to describe the development and advance applications of digital television, now
simply referred to as DTV.


This is a digital video camera standard for recording 1080i and 720p HD video sources onto memory cards such as the SD Memory Card, and onto DVD discs, by using MPEG-4 AVC/H.264 high-compression technology. When Dolby Digital or linear PCM is used, this system enables Dolby Digital audio recording in maximum 5.1-channel surround sound.



The front surface of a loudspeaker on which the drivers are mounted.

Balanced Input

A connection with three conductors: two identical signal conductors that are 180 degrees out of phase with each other, and one ground. This type of connection is very resistant to line noise.

Banana Jack

A small tubular connector found on loudspeakers and power amplifiers for connecting speaker cables terminated with banana plugs.

Banana Plug

A common speaker-cable termination that fits into a banana jack.


A two-part filter that cuts both higher and lower frequencies around a center band. A bandpass enclosure cuts high frequencies by acoustic cancellation and low frequencies by natural physical limitations on bass response.


This term describes data-carrying capacity–in other words, how much (and how fast) data flows on a given transmission path.

Barn Doors

A term used in television production to describe the effect that occurs when a 4:3 image is viewed on a 16:9 screen. When this happens, viewers see black bars on the sides of the screen or “barn doors.”


Low frequencies; those below approximately 200 Hz.

Bass Extension

The lowest frequency an audio system will reproduce. A measure of how deeply an audio system or loudspeaker will reproduce bass.

Bass Reflex

Speaker with a hole or slot in the cabinet that allows sound inside the cabinet to emerge into the listening room. Bass reflex speakers have deeper bass extension than speakers with sealed cabinets but that bass is generally less tightly controlled Also called vented or ported. Contrast with “infinite baffle.”

Before Color Temp

The color temperature at a given brightness level before grayscale calibration. Usually expressed in degrees Kelvin; ideally as close to 6,500K as possible.

Before Grayscale Variation

Before calibration, using the television’s best available presets, the average amount of variation from an ideal of 6,500K, measured over the entire range of the grayscale–typically 20 to 100 IRE in 10-IRE increments.


The frame around a CRT or LCD screen.

Binding Post

A connection on power amplifiers and loudspeakers for attaching loudspeaker cables.


  1. The condition of possessing two pole sets. In a conventional (non-FET) transistor, one pole set exists between the base and collector, and the other pole set exists between the base and emitter.

  2. Speakers that consist of two driver arrays facing opposite directions and wired in electrical phase with one another to create a more diffuse soundstage.

Bipolar Speaker

A speaker that produces sound equally from the front and the back. Unlike the dipolar speaker, the bipolar front and rear soundwaves are in-phase with each other.

Bipolar Transistor

Most common transistor type in audio electronics. Name bipolar(two poles) comes from fact that current flows through two types of semiconductor material, P and N. Bipolar transistors are either NPN or PNP types, which refers to the polarity of their operating voltages.


An abbreviation for binary digit. This is a single-digit binary value, consisting of the number 1 or 0. Each tiny pit on the surface of an optical disc holds one bit of information.


Bitstream refers to a method of transmitting recorded digital signals as a digital stream without any conversion.

Bit Rate

A range of frequencies used to transmit information such as picture and sound. For TV broadcasters, the FCC has allocated 6 MHz for each channel. For DTV, the maximum bit rate possible within the bandwidth is 19.4 Mbps, which is one HDTV channel. SDTV has a lower bit rate; therefore the bandwidth can accommodate more than one channel.


A method of connecting an amplifier or receiver to a speaker in which separate wires are run between the amp and the woofer and the amp and the tweeter.

Black Level

Black level is the measurement of the deepest level of black as configured in a TV’s settings. Most TVs need to be calibrated so that the black level is a true black; otherwise the colors will be muddled.


Sonic description of a component that emphasizes the upper harmonics of an instruments sound, while de-emphasizing the lower harmonics and fundamental. A bleached sound is thin, bright, and lacking warmth.


Sonic description of a sense of air around instrumental images. Boomy Excessive bass, particularly over a wide band of frequencies.


Blu-ray disc is a next-generation entertainment optical storage format. Though it resembles a DVD, a Blu-ray disc has a current maximum capacity of 50 GB and can only be played on a player with a Blu-ray drive. This produces a progressive video image resolution of up to 1920 x 1080, better known as 1080p–the best picture quality currently available. Blu-ray’s picture presentation even tops that of an HDTV broadcast, and its hard coating is also much more resistant to scratches and fingerprints than DVDs or CDs.

Bone Front and Rear Projection Screen

The bone color is a Hybrid to allow both front and rear
projection. These screens have higher gain from the rear.


To increase, make louder or brighter; opposite of attenuate.


Combining two channels of an amplifier to make one channel that’s more powerful. One channel amplifies the positive portion of an audio signal and the other channel amplifies the negative portion, which are then combined at the output.


A measurement of the light output that can be displayed. The lower the brightness, the more that ambient room light will interfere with a display. Measured in nits.


A midrange or treble character that makes instrumental timbres sound harsh. Contrast with liquid.


Electronic circuit that isolates one component or circuit stage from another. A preamplifier is a buffer because it acts as an intermediary between source components and a power amplifier. The preamplifier buffering function relieves the source components of the burden of driving a power amplifier.



CableCARD is an actual credit card-sized card that cable television companies provide to their users so that they can receive high-definition television programming. The card is fitted into an HD-ready TV. The term can also refer to systems of giving their users high-definition TV without an actual card that some cable companies provide.

Cable Equalization

A technology used in many HDMI receiver chips to boost the incoming signal, allowing the sink device (TV, projector, monitor, etc.) to compensate for weaker signals. Components employing cable equalization technology can be connected with longer cable runs than might otherwise be practical.


To properly enjoy television or movies in high definition, your new HDTV needs to be calibrated so that the black levels are true black and the white levels are true white–this keeps the colors from getting muddled. You can do this yourself or hire a professional to calibrate your HDTV for you.


The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation.

Capacitive Reactance

Property of capacitance that blocks low frequencies but passes high frequencies. Capacitive reactance makes a capacitor behave as a frequency-dependent resistor. Because of capacitive reactance, a capacitor connected to a tweeter allows treble to pass but blocks bass.

Cascading Crossovers

Two crossovers used in series on the same signal in the same frequency range causing greater attenuation of the out-of-band signal. For example,using the crossover in a receiver’s bass management setting and the one in a subwoofer simultaneously will create an exaggerated loss of signal.

CAT-5/CAT-6 Cable

Category 5 and Category 6 cabling is used in Ethernet and Fast Ethernet networks, and has also been adapted to transmit an HDMI signal. Both cables feature four twisted-pair copper wires and an RJ-45 connector, with the main difference being that CAT-6 has tighter tolerances for line noise and crosstalk. CAT-5/CAT-6 has been successfully used to transmit HDMI over extremely long cable runs, i.e. 40-50 meters.


Technical name for the TV signal that carries the color information (red, green, and blue) needed to produce a color picture; often called chroma.

Chrominance-To-Luminance Delay

Video artifact caused by the color signal lagging the brightness signal; appears as color smearing on the left edges of some onscreen objects; easiest to see with a test pattern that has a colored vertical stripe running down the middle of a white field.


Mode of amplifier operation in which a transistor or tube amplifies the entire audio signal.


Mode of amplifier operation in which one tube or transistor amplifies the positive half of an audio signal, and a second tube or transistor amplifies the negative half.


Mode of amplifier operation in which the output stage operates in Class-A at low output power, then switches to Class-B at higher output power.

Coaxial Cables: Analog and Digital

Coaxial cables are analog and are used to carry high-frequency signals over long distances and are shielded by three layers to prevent accumulating background noise over the journey. They are still in wide use today for transmitting radio communication, cable television, and Internet.

Digital coaxial cables are used for connecting things over short distances, such as those between DVD players and TVs. They are falling out of favor in preference of component video cables and, even more so, HDMI cables.

Color Balance

A CRT monitor uses three electron guns (red, green, and blue) to excite the phosphors that make up the pixels in an image. Color balance refers to the relative strength of the signal from each of the three guns. If the blue gun is turned up higher than the other two, for example, you will see a bluish tint on the screen. Many monitors provide color-adjustment controls that allow you to adjust the color balance.

Color Decoder

Component in all televisions that translates color-signal information from the source for display on the TV. ATSC and NTSC require two separate decoder matrices. Practically speaking, many color decoders accentuate red to compensate for a blue color temperature, a phenomenon known as red push.

Color Purity

Because CRT monitors use electromagnetism to control their electron guns, magnetic fields build up within the monitor and cause distortions that appear as colored patches on the screen. A monitor has good color purity if no such discolorations are visible (they are easiest to see on a white background). The magnetic fields that cause problems with color purity can sometimes be eliminated by degaussing.

Color saturation

A monitor with good color saturation can display subtle color changes distinctly so that the human eye perceives the differences. If similar colors blend together or if colors appear dark, they are oversaturated; colors that appear washed-out and faded are undersaturated.

Color Temperature

Sometimes called white balance and expressed in degrees Kelvin or just Kelvins, this is the color of gray at different levels from black to white. Since color information overlays the black-and-white information in a TV signal, color temperature affects the entire range of color. The National Television Standards Committee (NTSC) standard is 6,500K, but typically manufacturers ship their TVs with color temperatures ranging from about 7,000K to 12,000K, on the blue side of the color spectrum, to make sets as bright as possible to stand out on a brightly lit showroom sales floor. Some sets have a selectable color temperature.

Color Tracking

Each pixel on a CRT monitor’s screen consists of red, green, and blue spots of phosphor, each lit up by a separate electron gun. Color tracking refers to a monitor’s ability to keep all three electron guns operating at equal strength when displaying different brightness levels. In practice, one gun tends to overpower the other two, resulting in slight reddish, greenish, or bluish hues that are visible in dark-gray areas of an image.

Color Wheel

A device used in single-chip DLP front- and rear-projection that filters light into red, green, and blue components, which are then combined to create a picture. The color wheel is positioned between the lamp and the screen, and it spins faster than the eye can see to select the correct color. The speed of the color wheel is a significant factor in the prevalence of the rainbow effect.

Comb Filter

Component in all televisions that separates the chrominance and luminance from one another in composite-video connections. Good comb filtering enhances fine detail, cleans up image outlines, and eliminates most extraneous colors. Comb filters do not affect S-Video, component-video or digital-video connections.

Component Video

The elements that make up a video signal, consisting of luminance and two separate chrominance signals, expressed either as Y R-Y B-Y or Y Pb Pr.

Composite Video

A type of video signal in which all the necessary video information is combined into one signal. This is the type of signal used for broadcast TV in the United States. Most computer monitors use RGB video, in which the red, blue, and green signals are sent separately to produce a sharper image.


Compression: Taking a large amount of information/data, and ‘re-writing’ it so that the new data takes up less space (on a Blu-ray or CD, for examples). This is known as “compressing” the data (or “encoding”). Before the data can be used again, it must be “decompressed” (or “decoded”). Some Blu-ray players can decompress data on their own – then send it to the receiver (as uncompressed PCM) to play it. Some must send the compressed data to an audio receiver first, and the audio receiver must then perform the decompression and play the audio. This depends on what compression method has been used, and if that player is capable of performing the decompression itself. Additionally, not all compression methods are equal. Some processes allow for exact copies of the original audio to be produced (Lossless), others do not produce exact copies of the original data and therefore some information is lost (Lossy). Some of the ‘styles’ of audio compression include: Dolby Digital, DTS, Dolby TrueHD, DTS-HD Master Audio (MA). See Bitstream. See PCM. See Lossy. See Lossless.

Contrast Ratio

The difference in light intensity between the brightest white and the darkest black that a display device can produce. A higher the contrast ratio is better than a lower one.


Color CRTs rely on three separate electrical beams to project simultaneous red, green, and blue images; these combine to form a full-color image. If these beams are not precisely aligned, the red, green, and blue portions of the image may not overlap correctly, degrading the overall image quality. When the three beams converge correctly at all points on the display, you get a perfect image.


A component that divides an audio signal into two or more ranges by frequency, sending, for example, low frequencies to one output and high frequencies to another. An active crossover is powered and divides the line-level audio signal prior to amplification. A passive crossover uses no external power supply and may be used either at line level or, more commonly, at speaker level to divide the signal after amplification and send the low frequencies to the woofer and the high frequencies to the tweeter.

Crossover Frequency

The frequency at which an audio signal is divided. 80 Hz is a typical subwoofer crossover point and is the recommended crossover point in theatrical and home THX systems. Frequencies below 80 Hz are sent to the subwoofer; signals above 80 Hz are sent to the main speakers.

Crossover Slope

The rate of attenuation expressed in decibels of change for every octave away from the crossover frequency.



Of or pertaining to the control of vibration by electrical or mechanical means.

Damping Material

Any material that absorbs sound waves and eliminates acoustic energy by converting it into a different form. Fibrous material, for example, turns acoustic energy into heat via friction.


Vertically symmetrical driver array. Typically consists of a tweeter mounted between two woofers. Creates a more-vertically directional sound with evenly spaced lobes in the off-axis response when compared with asymmetrical driver arrays.


Abbreviation of “Digital Broadcast Satellite” - refers to digital TV transmissions via satellite.
Defeatable edge enhancement

Ability of a TV to not introduce any extra edge enhancement.


The Display Data Channel, one of the channels in an HDMI connection. DDC allows devices to assess each others’ capabilities and adjust themselves accordingly. For example, a DVD player can discover the maximum resolution of the monitor it’s connected to by reading the monitor’s EDID ROM chip, and optimize its signal output to match that monitor’s display capabilities.


Digital Digital Digital. A designation that indicates the recorded material was first recorded with digital equipment, then remixed on digital equipment and finally placed onto a digital recording medium…

Decibel (dB)

A logarithmic measurement unit that describes a sound’s relative loudness, though it can also be used to describe the relative difference between two power levels. A decibel is one tenth of a Bel. In sound, decibels generally measure a scale from 0 (the threshold of hearing) to 120-140 dB (the threshold of pain). A 3dB difference equates to a doubling of power. A 10dB difference is required to double the subjective volume. A 1dB difference over a broad frequency range is noticeable to most people, while a 0.2dB difference can affect the subjective impression of a sound.

Deep Color

Deep Color refers to the use of various color depths in displays, up from the 24­bit depths in previous versions of the HDMI specification. This extra bit depth allows HDTV’s and other displays go from millions of colors to billions of colors and eliminate on ­screen color banding for smooth tonal transitions and subtle gradations between colors. The increased contrast ratio can represent many times more shades of gray between black and white. Also Deep Color increases the number of available colors within the boundaries defined by the RGB or YCbCr color space.


The earth’s natural magnetism can cause unwanted magnetic fields to build up inside a monitor, causing a loss of color purity. A monitor’s degaussing control removes these stray fields.


The time difference between a sonic event and its perception at the listening position (sound traveling through space is delayed according to the distance it travels). People perceive spaciousness by the delay between the arrival of direct and reflected sound (larger spaces cause longer delays).


The part of a dynamic loudspeaker attached to the voice coil that produces sound. It usually has the shape of a cone or dome.


In audio, the scattering of sound waves, reducing the sense of localization. In video, the scattering of light waves, reducing hot spotting, as in a diffusion screen.


Acoustical treatment device that preserves sound energy by reflecting it evenly in multiple directions, as opposed to a flat surface, which reflects a majority of the sound energy in one direction.

Digital Intermediate (often abbreviated as DI)

Describes the process of digitizing a motion picture and manipulating color and other image characteristics to change the look, and is usually the final creative adjustment to a movie before distribution in theaters. It is distinguished from the telecine process in which film is scanned and color is manipulated but only intended for video and television distribution. A digital intermediate is also customarily done at higher resolution and with greater color fidelity than telecine transfers and utilizes only digital tools (no analog video devices).

Digital Cable Ready

Official term for an HDTV that conforms to the plug-and-play digital cable TV standard using POD (point of deployment) access cards, also called CableCARDs. With cable systems that comply with the standard, users can plug the cable directly into an HDTV set, then enjoy HDTV and digital cable without having to use a separate set-top box. Sets with interactive functionality are labeled Interactive Digital Cable Ready.

Digital Comb Filter

Device that separates the luminance and chrominance parts of a video signal in the digital domain, which provides enhanced color purity and reduced dot crawl over the analog variety.

Digital Television (DTV)

Refers to all formats of digital television, including high definition television (HDTV), and standard definition television (SDTV). Also referred to as ATV (Advanced TV)


Direct-drive Image Light Amplifier LCoS-based rear-projection technology developed and used by JVC. In its rear-projection products, the company calls the technology HD-ILA.


Speakers with drivers on opposite faces that are wired electrically out of phase, creating an area of cancellation to the sides. Recommended by THX for use as surround speakers, with null directed at the listener to create a more ambient and non-localizable effect.

Direct-Stream Digital

A format for encoding high-resolution audio signals. It uses a 1-bit encoder with a sampling rate of 2,822,400 samples per second (verses 44,100 for CD). Used to encode six high-resolution channels on SACD.

Direct-View Television

Display whose image is created on the surface from which it is viewed.

Display Size

A display’s length (in inches or centimeters) taken diagonally from one corner to the opposite corner. Unless it specifically states viewable screen area, a CRT’s measurement encompasses the full face of the picture tube, including the part concealed by the bezel. On an LCD, only the viewable screen is measured.


Creating the illusion of new colors and shades by varying the pattern of dots.


Digital light processing. A micro display technology invented by Texas Instruments, DLP is based on a digital micro mirror device (DMD), a chip with millions of hinged, microscopic mirrors attached, each of which corresponds to a single pixel in the projected image. Red, green, and blue light filtered through a color wheel is directed alternately onto the DMD, which switches on and off up to 5,000 times a second. The reflected light is directed through a lens and onto a screen, creating an image. High-end HDTV projectors use a three-chip solution, with separate DMD’s for green, red, and blue, and fore go the color wheel.

Dolby Digital

Dolby Digital is a proprietary technology used for creating and reproducing digital surround sound (also called AC-3, or 5:1). The 5:1 format refers to the way digital sound is recorded on six separate tracks: front left, front right, front center, rear left, and rear right, with an extra track reserved for very low bass. This method mimics the three-dimensional quality of sound in real life. Although analog surround sound (called Dolby Pro Logic) also often uses six speakers, the analog format simply splits a traditional stereo signal into front and rear components.

Dolby Digital EX

Dolby Digital EX creates 6 full bandwidth output channels from 5.1­channel sources. This is done using a matrix decoder that derives 3 surround channels from the 2 in the original recording. For the best results, Dolby Digital EX should be used with movie sound tracks recorded with Dolby Digital Surround EX. With this additional channel, you can experience more dynamic and realistic moving sound especially with scenes with “fly­over” and “fly around” effects.

Dolby Digital Surround EX

Dolby Digital Surround EX was co-developed by Dolby and Lucas film THX in time for the release in May 1999 of Star Wars Episode I: The Phantom Menace. It provides an economical and backwards-compatible means for 5.1 soundtracks to carry a sixth, center back surround channel for improved localization of effects. The extra surround channel is matrix encoded onto the discrete Left Surround and Right Surround channels of the 5.1 mix, much like the front center channel on Dolby Surround encoded stereo soundtracks. The result can be played without loss of information on standard 5.1 systems, or played in 6.1 or 7.1 on systems equipped with Surround EX decoding and additional speakers. Dolby Digital Surround EX has since been used for the Star Wars prequels on the DVD versions and also the remastered original Star Wars trilogy. A number of DVDs have Dolby Digital Surround EX audio option.

Dolby Digital Plus

Dolby Digital Plus is an advanced audio technology developed or high definition programming and media including HD broadcasts, HD DVD, and Blu-­ray Disc. Selected as a mandatory audio standard for HD DVD and as an optional audio standard for Blu-­ray Disc, this technology delivers multichannel sound with discrete channel output. Supporting bit rates up to 6.0 Mbps,Dolby Digital Plus can carry up to 7.1 discreet audio channels simultaneously. Supported by HDMI version 1.3 and designed for the optical disc players and AV receivers/amplifiers of the future, Dolby Digital Plus also remains fully compatible with the existing multichannel audio systems that incorporate Dolby Digital.

Dolby Pro Logic

The analog version of surround sound for home video, Dolby Pro Logic splits a regular stereo signal into front and back components, and then usually puts a slight delay on the rear speakers to create an illusion of 3D audio depth. A mono center speaker is usually added to reduce disorientation caused by hearing stereo sound from the sides while watching video in the center.

Dolby Pro Logic II

Dolby Pro Logic II is an improved technique used to decode vast numbers of existing Dolby Surround sources. This new technology enables a discrete 5­channel playback with 2 front left and right channels, 1 center channel, and 2 surround left and right channels instead of only 1 surround channel for conventional Pro Logic technology. There are three modes available: “Music mode” for music sources, “Movie mode” for movie sources and “Game mode” for game sources.

Dolby Pro Logic IIx

Dolby Pro Logic IIx is a new technology enabling discrete multi­channel playback from 2­channel or multi­channel sources. There are three modes available: “Music mode” for music sources,” Movie mode” for movie sources (for 2­channel sources only) and “Game mode” for game sources.

Dolby Surround

Dolby Surround uses a 4­channel analog recording system to reproduce realistic and dynamic sound effects: 2 front left and right channels (stereo), a center channel for dialog (monaural), and a surround channel for special sound effects (monaural). The surround channel reproduces sound within a narrow frequency range. Dolby Surround is widely used with nearly all video tapes and laser discs and in many TV and cable broadcasts as well.

Dolby TrueHD

Dolby TrueHD is an advanced lossless audio technology developed for high definition disc based media including HD DVD and Blu-­ray Disc. Selected as a mandatory audio standard for HD DVD and as an optional audio standard for Blu-­ray Disc, this technology delivers sound that is bit ­for ­bit identical to the studio master, offering a high definition home theater experience. Supporting bit rates up to 18.0 Mbps, Dolby TrueHD can carry up to 8 discrete channels of 24­bit/96 kHz audio simultaneously. supported by HDMI version 1.3 and designed for the optical disc players and AV receivers/amplifiers of the future, Dolby TrueHD also remains fully compatible with the existing multi-channel audio systems and retains the metadata capability of Dolby Digital, allowing dialog normalization and dynamic range control.


In DTV, the conversion from a higher-resolution input signal number to a lower one. For example, some DTV receivers can be set to downconvert an HDTV 1080i signal to a standard 480i signal that any TV can display.


Missing information from a broadcast or recorded media and typically show up as white specks in an analog environment. Dropout is more pronounced with interframe compression techniques such as MPEG because the error displays until the next complete frame is drawn, otherwise known as an I-frame. This can take up to ½ a second.


Direct Stream Digital (DSD) technology stores audio signals on digital storage media, such as Super Audio CDs. Using DSD, signals are stored as single bit values at a high ­frequency sampling rate of 2.8224 MHz, while noise shaping and over sampling are used to reduce distortion, a common occurrence with very high quantization of audio signals. Due to the high sampling rate, better audio quality can be achieved than that offered by the PCM format used for normal audio CDs.

DSP (Digital Signal Processing)

The process used to alter (usually in real time) an audio or video signal in such a way that it sounds or looks different from the original. Examples of signal processing include: boosting bass, simulating a 3D environment, reverb, chorus, and so on.


Digital Transmission Copy Protection, A HDTV copy-protection scheme more commonly called 5C.


Digital Transmission Licensing Administrator, The licensing organization for the 5C DTCP HDTV copy-protection technology.

DTS 96/24

DTS 96/24 offers an unprecedented level of audio quality for multi­channel sound on DVD video, and is fully backward compatible with all DTS decoders. “96” refers to a 96 kHz sampling rate compared to the typical 48 kHz sampling rate. “24” refers to 24­bit word length. DTS 96/24 offers sound quality transparent to the original 96/24 master, and 96/24 5.1­channel sound with full ­quality full ­motion video for music programs and motion picture soundtracks on DVD video.

DTS Digital Surround

DTS digital surround was developed to replace the analog soundtracks of movies with a 6.1 ­channel digital sound track, and is now rapidly gaining popularity in movie theaters around the world. DTS, Inc. has developed a home theater system so that you can enjoy the depth of sound and natural spatial representation of DTS digital surround in your home. This system produces practically distortion ­free 6.1­channel sound (technically, front left and right, center, surround left and right, and LFE 0.1 (subwoofer) channels for a total of 5.1 channels).

DTS Express

DTS Express is an advanced audio technology for the optional feature on Blu­ray Disc or HD DVD, which offers high ­quality, low bit rate audio optimized for network streaming, and Internet applications. DTS Express is used for the Secondary Audio feature of Blu-­ray Disc or the Sub Audio feature of HD DVD. These features deliver audio commentaries (for example, the additional commentaries made by the director of a film) on demand by the users via the Internet, etc. DTS Express signals are mixed down with the main audio stream on the player component, and the component sends the mixed audio stream to the AV receivers/amplifiers via digital coaxial, digital optical or analog connections.

DTS-­HD High Resolution Audio

DTS-­HD High Resolution Audio is an high resolution audio technology developed for high ­definition disc ­based media including HD DVD and Blu-­ray Disc. Selected as an optional audio standard for both HD DVD and Blu­ray Disc, this technology delivers sound that is virtually indistinguishable from the original, offering a high ­definition home theater experience. Supporting bitrates up to 3.0 Mbps for HD DVD and 6.0 Mbps for Blu-­ray Disc, DTS-­HD High Resolution Audio can carry up to 7.1 discrete channels of 24­bit/96 kHz audio simultaneously. Supported by HDMI version 1.3 and designed for the optical disc players and AV receivers/amplifiers of the future, DTS­HD High Resolution Audio also remains fully compatible with the existing multichannel audio systems that incorporate DTS Digital Surround.

DTS-­HD Master Audio

DTS-­HD Master Audio is an advanced lossless audio technology developed for high ­definition disc ­based media including HD DVD and Blu-­ray Disc. Selected as a mandatory audio standard for both HD DVD and Blu-­ray Disc, this technology delivers sound that is bit ­for ­bit identical to the studio master, offering a high ­definition home theater experience. Supporting bitrates up to 18.0 Mbps for HD DVD and up to 24.5 Mbps for Blu-­ray Disc, DTS-­HD Master Audio can carry up to 7.1 discrete channels of 24­bit/96 kHz audio simultaneously. Supported by HDMI version 1.3 and designed for the optical disc players and AV receivers/amplifiers of the future, DTS-­HD Master Audio also remains fully compatible with the existing multichannel audio systems that incorporate DTS Digital Surround.


Digital Visual Interface, A digital interface specification created by an industry consortium, the Digital Display Working Group. This universal standard for connecting flat-panel monitors is also used for data projectors, plasma displays, and digital TVs. Using a DVI connector and port, a digital signal sent to an analog device is converted into an analog signal (if the device is digital, such as a flat-panel monitor, no conversion is necessary). There are three different DVI configurations: DVI-A for analog signals, DVI-D for digital signals, and DVI-I (integrated) for both analog and digital signals.


Digital video recorder, A television recorder such as Replay and TiVo that uses a hard drive, an EPG, and internal processing to drastically simplify programmed recording and playback of recorded programs. A DVR vastly increases recording time compared to VCRs or DVD-recording decks; often enables smart programming, in which the device records an entire series or programming defined by keywords, genre, or personnel; and offers pause control over “live” broadcasts. Also called personal video recorder (PVR) or hard disk video recorder.


Edge Enhancement

Generic term for artificial edges created around onscreen objects. With already-sharp, high-resolution sources such as DVD and HDTV, it actually obscures detail and increases noise. Scan-velocity modulation circuits, a TV’s sharpness control, or the source itself (such as a DVD) are some possible sources of edge enhancement.


Enhanced Definition Television, Also used to describe plasma and other fixed-pixel displays that have 852x480 resolution. They can show an HDTV image but don’t provide as much detail as higher-resolution displays.

Electron Gun

A color CRT contains three electron guns that shoot electron beams, causing red ®, green (G), or blue (B) phosphors on the inside front of the screen to light up.


Electronic program guide. An on-screen display of channels and program data.


False Contouring

An artifact common to fixed-pixel displays that produces splotchy, distinct sections in what should be gradual gradations of color or shadows. Also referred to as solarization and posterization.

Fiber-Optic Cable

Fiber-optic cables consist of thin filaments of glass (or other transparent materials) that can carry beams of light. A laser transmitter encodes frequency signals into pulses of light and sends them down the optical fiber to a receiver, which translates the light signals back into frequencies. Less susceptible to noise and interference than other kinds of cables, optical fibers can transmit data greater distances without amplification. But because the glass filaments are fragile, optical fiber must be run underground rather than overhead on telephone poles.

Fixed-Pixel Display

Digital televisions that use discrete pixels to create a picture image, such as plasma, LCD, DLP, LCoS, or any non-CRT display device. In the case of DLP, for instance, each pixel is represented by one of the hundreds of thousands of tiny mirrors mounted on a DLP chip.

Flat-Panel Display

This term usually refers to the LCDs used for notebook computers and desktop displays, but it could also refer to other technologies, such as plasma, that produce flat-shaped screens as opposed to the bulkier CRT technology.

Flat-Panel TV

Video display typically using gas plasma or LCD technology and that measures only a few inches thick.


Frames per second. The number of individual still pictures that pass by every second to create a moving image. Film runs at 24fps, while video, including DVD, runs at 30fps. To compensate for the difference, 2:3 pull-down detection is used.


Take a look at a representation of an analog signal, and you’ll see a series of waves. We measure the frequency of these waves by determining how many of them pass a specific point in a given amount of time. This frequency is often measured in cycles per second, or hertz.

Front Projection

Type of TV system in which the picture is projected onto a reflective screen or even a wall. The larger the picture, the more visible the pixels or scan lines and the darker the image. CRT systems use three tubes (red, blue, and green), whereas LCD and DLP uses a single projection lens.

[B]A work in progress

This Glossary is a concise collection of some of the terminology that you may confront; it is not intended to be a complete compendium of technical terms.



Measures the light-reflecting ability of a projection screen. The higher the number, the greater the amount of light reflected back to the viewer.

[B]Geometric Distortion[/B]

Unnatural bowing of straight lines or other distortion of shapes, especially at the sides and corners in a TV picture.

[B]Geometric Linearity[/B]

Ability of a television to reproduce lines, shapes, and sizes accurately.


  1. A visual phenomenon in LCDs and other digital displays where an image moves faster than the display can redraw it, thereby leaving a trail of former versions of the image in the wake of the redrawn image Ghosting might also be called trailing or streaking. As LCDs evolve, faster pixel-response times are reducing the ghosting problem.

  2. In television and in flat-panel displays such as LCDs, a shadowy ghost of a displayed image that may appear due to signal interference. DTV broadcasts can suffer from ghosting, which is sometimes called multipath.

  3. CRTs that display the same image for a long period of time will eventually develop a permanent shadow burned onto the screen, called a ghost. The advent of screensavers has helped reduce the occurrence of ghosting.


Range of gray at different intensities from completely black to completely white. Since color information is overlaid atop black-and-white information in a composite, S-Video, and component-video signal, the ideal is to set the entire range of the grayscale as close to the standard of 6,500K as possible to preserve color fidelity.
Grayscale Variation[/B]

The average variation above or below 6,500K, measured on the grayscale from 20 to 100 IRE in 10-IRE increments.

[B]Grey Front Projection Screen[/B]

A grey screen will provide greater contrast and help bring out the blacks. The downside is the loss of gain.

[B]Grey Rear Projection Screen[/B]

Grey is a common color used in rear projection because it provides contrast and prevents a hot spot from the projector lamp. Rear projection screens have much higher gains than front screens and do not lose meaningful gain when grey.


[B]Hanging Dots[/B]

An artifact of composite video signals that appears as a stationary, zipper-like, horizontal border between colors.


High-bandwidth Digital Content Protection. Copy-protection scheme developed by Intel to be used in conjunction with DVI and HDMI connections.


The newest and currently the best type of cable connection for your HDTV is HDMI (High-Definition Multimedia Interface). An all-digital interface, HDMI carries both high-resolution video and uncompressed multichannel audio through a single cable. Use it to connect any digital audio/video source (set-top box, DVD player, PC, video game system, or AV receiver) with a compatible digital audio and/or video monitor (HDTV). It is an alternative to component video, separate video, DVI, coaxial, and other forms of connector interfaces, and is primarily used for transmitting video in high definition. Incorporates HDCP digital copy protection.

[B]HDMI 1.3[/B]

HDMI 1.3 is a new technology standard that roughly doubles the data-carrying bandwidth of HDMI cable from 5 Gbps to 10 Gbps. In order for this to happen, your HDMI input/outputs and HDMI cable must all be of the 1.3 standard. The extra data capacity enables even better picture (a wider range of colors can be displayed) and sound (more audio formats).

If you already have a home entertainment system, HDMI 1.3 is backwards compatible with HDMI 1.1, which is the current standard for most HDTVs, receivers, high and standard definition players.

[B]HDMI Passthrough/Switching[/B]

No repeated handshakes of the HDCP codes. Will only allow video to pass through and requires a separate audio connection.

[B]HDMI Repeater[/B]

Repeats the the handshakes of the HDCP codes and allows both video and audio to pass through.

  • Note future updates of the HDCP code may require a firmware update or a device that support the change.

[B]HDMI Sink[/B]

A device that receives an HDMI signal, such as an HDTV.

[B]HDMI Source[/B]

A device that sends an HDMI signal, such as a DVD player or Set-top box.


High-definition digital video disc. Several formats have been proposed for these high-capacity DVDs, including Blu-ray.


High-definition Direct-drive Image Light Amplifier.


High-Definition Television, A TV signal that offers a much higher resolution and a wider aspect ratio than traditional NTSC (regular broadcast) signals. It can also refer to the actual television sets that pick up these signals.

High Definition Television. Not the same as DTV, it’s actually a subset of DTV. The HDTV standard requires a screen resolution of 720p or better.

  • 720p - The picture is 1280x720 pixels, sent at 60 complete frames per second.

  • 1080i - The picture is 1920x1080 pixels, sent at 60 interlaced frames per second (30 complete frames per second).

  • 1080p - The picture is 1920x1080 pixels, sent at 60 complete frames per second.

[B]HDTV Blur[/B]

It is a common term used to describe a number of different artifacts on consumer modern high definition television sets.

The following factors are generally the primary or secondary causes of HDTV blur; in some cases more than one of these factors may be in play at the studio or receiver end of the transmission chain.

  • Pixel response time on LCD displays (blur in the color response of the active pixel)

  • Slower camera shutter speeds common in Hollywood production films (blur in the HDV content of the film)

  • Blur from eye tracking fast moving objects on sample-and-hold LCD, Plasma, or Microdisplay.

  • Resolution resampling (blur due to resizing image to fit the native resolution of the HDTV)

  • Blur due to 3:2 pulldown and/or motion-speed irregularities in framerate conversions from film to video

  • Computer generated motion blur introduced by video games.


Used to describe any TV that can display high-definition formats when connected to a separate HDTV tuner or source. These TVs generally have built-in tuners for receiving regular NTSC broadcasts, but not ATSC digital broadcasts. The CEA’s official term for an HDTV-ready TV is HDTV monitor.

[B]HDTV Monitor[/B]

Official CEA term for HDTV-ready.

[B]High Gain Screen[/B]

Material that reflects more light than a reference material. Increases a projector’s light output at the expense of uniformity.

[B]High Pass[/B]

A filter that passes high frequencies, and attenuates low frequencies.

[B]Hz - Hertz[/B]

Also called cycles per second and in video displays is the rate at which an image is refreshed.



The Image Constraint Token (ICT) is a digital flag within the AACS (Advanced Access Content System) that determines how Blu-ray and HD DVD players output high defintion video signals through the player’s component outputs.

The Advanced Access Content System (AACS) is the digital rights management (DRM) standard which will be used by Blu-ray and HD DVD to protect movies from unauthorized duplication.

If the ICT token is set on a Blu-ray or HD DVD disc, then the player will down-convert the video resolution through analog outputs from 1920 by 1080 pixels to 960 by 540. The purpose of ICT is to prevent pirates from creating high resolution copies of HD DVD and Blu-ray discs via the unsecured analog outputs.

The video output through HDMI is unaffected by ICT since the HDMI output is copy protected by High-Bandwidth Digital Content Protection (HDCP).

The Image Constraint Token is set by the movie studio when a disc is mastered therefore whether the player down converts the video signal will be determined by the studio on a title by title basis. It is expected that most major movie studios will set the Image Constraint Token on all titles.

If the ICT is set, then your HDTV must have an HDMI input in order to watch high definition from a Blu-ray or HD DVD movie.

[B]IEEE 1394 (FireWire)[/B]

A digital interface developed by the IEEE 1394 working group. Transports data at 100, 200, or 400 Mbps. Can be used to connect digital television devices together. IEEE 1394 data transfer can be – “asynchronous” - or “isochronous.” Asynchronous transport is the traditional computer memory-mapped, load and store interface. Isochronous data channels provide guaranteed data transport at a pre-determined rate. This is especially important for time-critical multimedia data where just-in-time delivery eliminates the need for costly buffering.


An IRE is a unit used in the measurement of composite video signals. Its name is derived from the initials of the Institute of Radio Engineers.

[B]Integrated HDTV Tuner[/B]

The terrestrial ATSC high-definition tuner built into an HDTV, it allows the set to receive over-the-air HDTV broadcasts without having to attach a set-top box.

[B]Interlaced Display[/B]

A cathode-ray tube (CRT) display in which the electron guns skip every other line on their first pass, then fill in those lines on a second pass. This allows for a lower refresh rate at higher resolutions (such as 1,024x768) without producing flicker, but the scheme doesn’t work well when displaying animated graphics. Most monitors aren’t interlaced, but lower-quality display adapters pushed into high resolutions and high color sometimes do interlace. Opt for a noninterlaced monitor.

[B]Interlaced Scanning[/B]

Scan method used by the majority of televisions and the 1080i HDTV format. As opposed to progressive scanning in which the CRT’s electron beam scans or “paints” all lines at once, interlaced scanning TVs paint odd-numbered lines in succession, then go back and fill in the remaining even-numbered lines. This method is more prone to artifacts and less stable than progressive.

[B]I/O: Input/output[/B]

Typically refers to sending information or data signals to and from devices. Often used in referring to video/audio component connections.



A visual artifact that often occurs when film is transferred to video. The result is what appears to be jerky or stuttering camera movement, where it should be a smooth pan.


[B]Kelvin (K)[/B]

A temperature measurement scale where 0° Kelvin (0°K) is equal to absolute zero, the temperature at which all molecular movement ceases. One degree of Kelvin is equal to 1 degree of Celsius. The color temperature of large image devices is measured in Kelvin. The higher the temperature, the bluer the light.


Keystoning occurs when the projector is not perpendicular to the screen, thereby creating an image that is not rectangular.

[B]Keystone Correction[/B]

Keystone correction makes a projected image rectangular. This can be accomplished by positioning the projector to be perpendicular to the screen. Since this is not always possible, most projectors are equipped with keystone correction that allows the image to be keystone corrected (made rectangular) by adjusting optics, making mechanical adjustments, or applying digital scaling to the image. Keystone correction can be one or two dimensional and manual or automatic depending on the projector and the manufacturer. Be aware that digital scaling will introduce some artifacts that are more evident when viewing small text and less evident in presentation type material or video.


The time between a device being requested to do something and the start of the device actually doing it. It’s a measurement usually used for LCDs where the shorter the latency the better. NSTC requires a latency of no more than 16ms in order to update the screen in time without leaving a ghost of the previous image.


Liquid-Crystal Display, A television that employs a liquid-crystal display screen rather than a CRT; used in small, personal TVs, portable video equipment, front projectors, and larger flat-panel displays. An LCD projector uses a lamp to shine light through liquid-crystal panels, then through mirrors and lenses to the screen.


Liquid Crystal on Silicon. Whereas LCDs uses liquid crystals sandwiched between two glass plates, this newer hybrid projection TV technology employs liquid crystals coated on a silicon chip, which results in easier, lower-cost manufacturing and higher-resolution images.


Light-Emitting Diode,A semiconductor device that emits light when electrical current is applied to it. LEDs require very little power and can last for decades. They are used as indicator lights on electronic devices, for digital and alphanumeric readouts on equipment, in fiber optic data transmission, and in remote-control devices.

[B]Lens Shift[/B]

The Lens Shift feature of a projector allows the optical lens to be physically shifted up and down (vertical) and/or left and right (horizontal). Some lens shift mechanisms are motorized with vertical lens shift being the most popular. Lens shift can avoid or minimize the need for keystone correction. It is also used to geometrically align images when stacking projectors.


A wide-screen movie on DVD,laserdisc, or videotape presented in its original theatrical wide-screen width on a standard square 4:3 TV. The film is shown with black bars above and below the picture area to create the wider, theatrical image. Often used to indicate a nonanamorphic DVD.

[B]LFE 0.1 channel[/B]

This channel reproduces low­frequency signals. The frequency range of this channel is from 20 Hz to 120 Hz. This channel is counted as 0.1 because it only enforces a low­frequency range compared to the full­range reproduced by the other 5/6 channels in Dolby Digital or DTS 5.1/6.1­channel systems.

[B]Light Valve Projector[/B]

A projector that uses an imaging system that either blocks or reflects light such as LCD, LCoS or DLP.


Technology used in televisions to create a higher-quality picture by increasing the number of lines of resolution displayed; it can be a separate device or a feature built-in TVs, primarily DTVs. A poor-quality line-doubler can actually degrade the image from lower-resolution analog or digital signals.


A low-voltage pre-amplified signal usually between .3 and 5 volts.


A display’s ability to show an image’s geometric characteristics accurately. Also called geometric linearity.

[B]LNB: Low-Noise Block converter[/B]

The LNB sits at the end of a pole facing the dish of a satellite dish assembly. It converts the incoming signal to a lower set of frequencies to make them easier to send over a wire without distortion. The lower the rated degrees of an LNB, the cleaner the picture will be.

[B]Long Throw Lens[/B]

A long throw lens allows greater distance between the projector and the screen while being able to maintain the image size and brightness of a shorter throw lens for any given projector. Depending on the room, a long throw lens may be required due to mounting constraints nearer the projected image.


Lossless: Refers to audio that has been reproduced from the original source (Blu-ray disc, CD, eg.) without having lost any information. Lost information results in a ‘less-than-perfect’ reproduction of the audio track. Uncompressed PCM, Dolby True HD, and DTS-HD MA are examples of lossless audio feeds. All Blu-ray players are capable of transmitting uncompressed PCM data to a receiver using an HDMI cable. Not all players are capable of decoding/transmitting every type of compressed data. See your player’s user manual for details. See Compression. For comparison, See Lossy.


Lossy: Refers to audio that is not an exact reproduction of the original. During the recording/compression process, information has been lost, and may result in the perception of less quality/depth/richness of sound. Not all players are capable of decoding/transmitting every type of compressed data. See your player’s user manual for details. Examples of Lossy sound compression methods include DTS, Dolby Digital, and DTS-HD HR. See Compression. For comparison, See Lossless.

[B]Low Pass[/B]

A filter that only passes frequencies under a specified Hertz.


The unit of measure for the light output of a projector. Different manufacturers may rate their projectors’ light output differently, and these numbers are usually inflated. “Peak lumens” is measured by illuminating an area of about 10 percent of the screen size in the center of the display. This measurement ignores the reduction in brightness at the sides and corners of the screen.


Portion of a television transmission that controls brightness of the red, green, and blue proportions in a television picture. The standard luminance setting in a picture is 30 percent red, 60 percent green, and 10 percent blue. These numbers are adjusted to produce varying colors, grays, whites, and blacks.


[B]Macro Blocking[/B]

MPEG 2 encoding is a lossy compression based on Discrete Cosine Transformation (DCT). It breaks the image into small rectangular areas called macroblocks. Within these blocks the grid of picture elements (pixels) are encoded to represent their horizontal and vertical video frequencies. It does this so that when it has to throw out some information, it starts with the higher frequencies (finer detail) and works its way down.

Motion vectors is another compression technique that MPEG 2 uses to take advantage of redundant frame-to-frame information. The use of motion vectors allows the amount of DCT compression to be decreased. If there is so much motion that the encoder cannot keep up, it can no longer effectively use the motion vectors, and the amount of compression is increased. Fine detail is eliminated in each of the blocks, and what’s left is more of an average. Since each block probably has a different average, it makes a mosaic looking set of squares on the screen. When things slow down, and the encoder can decrease the amount of compression the detail will return.

[B]Moiré Pattern[/B]

An image artifact which is an interference pattern caused by two patterns overlaying each other. Looks like cross-hatching, herringbone or other patterns.

[B]Mosquito Noise[/B]

An artifact of MPEG compression which looks like a mosquito buzzing around. Usually found around sharp edges and most easily seen on solid color areas. It is a time dependent video compression impairment in which the high frequency spatial detail in video images having crisp edges is aliased intermittently.


Motion Picture Association of America, Industry association for producers of motion pictures.


A set of standards (pronounced “EM-peg”) for compressing multimedia files. MPEG-1 is used in CD-ROMs. MPEG-2 is used for a broad range of formats, including DVD, high-definition TV, and surround sound. MPEG-4 is a standard for low-bandwidth video telephony and multimedia on the World Wide Web. (MPEG-3 was merged into MPEG-2.) The acronym MPEG stands for Moving Picture Experts Group, a working group of the International Standards Organization.


Moving Picture Experts Group-2. Video-compression scheme used to condense digital video content for broadcast over thin TV bandwidths or via the Internet, and to squeeze full-length digital films onto a DVD.


Advanced compression scheme finalized October 1998, designed to enable transmission and reception of high-quality audio and video over the Internet and next-generation mobile telephones; potentially enables mobile video phones, video e-mail, and cordless video cameras. Two major versions are MPEG-4 Simple Profile for low-resolution digital video content, usually for distribution over the Internet, and MPEG-4 AVC (Advanced Video Coding), which offers faster and higher-quality compression than MPEG-2 for HDTV content.

[B]A work in progress

This Glossary is a concise collection of some of the terminology that you may confront; it is not intended to be a complete compendium of technical terms.


[B]Native Resolution[/B]

The resolution at which a TV or monitor is designed to display images. Image signals higher or lower than a specified native resolution must be converted to be displayed accurately. For example, a TV with a native resolution of 1080i can display 1080i images but may upconvert 480p images to 1080i. In contrast, a TV with a native resolution of 480p must downconvert a 1080i signal to 480p for display. CRT-based projection TVs can have more than one native resolution, but fixed-pixel displays such as LCD and DLP are limited to display one resolution and convert all others.


Neo:6 decodes the conventional 2 ­channel sources for 6­ channel playback by the specific decoder. It enables playback with the full ­range channels with higher separation just like digital discrete signal playback. There are two modes available: “Music mode” for music sources and “Cinema mode” for movie sources.

[B]Neural Surround[/B]

Neural Surround represents the latest advancement in surround technology and has been adopted by XM Satellite Radio for digital radio broadcast of surround recordings and live events in surround sound. Neural Surround™ employs psychoacoustic frequency domain processing which allows delivery of a more detailed sound stage with superior channel separation and localization of audio elements. System playback is scalable from 5.1 to 7.1 multi­channel surround playback.


A measurement of brightness. A nit is equal to one candela per square meter. The more nits, the greater the brightness.


A cathode-ray tube (CRT) display in which the electron guns paint every line on the screen each time they scan from top to bottom. This type of monitor produces less flicker than do interlaced displays.


A process that adjusts the volume of a sound recording so that it plays back at a consistent volume.

National Television Systems Committee, This body was established by the Federal Communications Commission (FCC) to set television and video standards in the United States. (The predominant standards outside the United States are PAL and SECAM.) The acronym refers to the television broadcast standard, which specifies 525 lines of resolution per second for broadcasts, and it combines blue, red, and green signals with an FM frequency for audio. NTSC should eventually be succeeded by HDTV (high-definition TV).



Organic Light-Emitting Diode, A display device that operates by sandwiching carbon-based films between two charged electrodes. OLED displays, originally developed by Kodak, are unlike LCDs in that they don’t require backlighting; instead, they emit light themselves. OLED displays offer many advantages over LCDs, including less power consumption and brighter output.

[B]Optical Fiber[/B]

A medium used for high-bandwidth data transmission in telecommunications and networking. Optical-fiber cables consist of bundles of thin glass or plastic filaments that carry beams of light. A laser transmitter encodes frequency signals into pulses of light and sends them down the optical fiber to a receiver, which translates the light signals back into frequencies. Less susceptible to noise and interference than other kinds of cable, optical fibers can transmit data for greater distances without requiring signal amplification. But because the filaments are fragile, optical-fiber cables must be run underground, which makes them expensive to install.


Onscreen Display, A dialog box that appears on a television screen and gives you access to display options and other functions, such as parental controls.



A component of an HDMV menu that is built up of different Button Object Groups (BOGs) Persistent Storage - The 64KB (minimum) of built-in player memory.


Phase Alternation Line, The television broadcast standard used in the U.K. and in many European countries. This standard specifies broadcasts of 625 horizontal lines of resolution per second, nearly 20 percent more than the U.S. standard, NTSC, of 525 lines.


Process of transferring a movie or other source material to videocassette, DVD, or broadcast so that it fits the 4:3 aspect ratio of most current TVs. This results in a significant amount of lost picture information, particularly in the width of the image, and sometimes involves panning unnaturally across the frame. At the beginning of a movie, there is often a disclaimer about the movie having been “…formatted to fit your TV.” That means it’s been converted to pan-and-scan.

[B]Passive Radiator[/B]

A radiating surface (usually similar to a conventional speaker cone) that is not electrically driven but shares the same air space in a sealed cabinet withan electrically driven loudspeaker. This arrangement is functionally similar to a loudspeaker with a vented (ported) cabinet, with the passive radiator serving the duties of the air in the port.

[B]PCM (Linear PCM)[/B]

PCM: “Pulse Code Modulation”. A specific way of transmitting digital sound information from one place to another. The PCM ‘style’ of data transmission sends the info “uncompressed”. This means that when it is sent from the data source (a Blu-ray disc, CD, etc.) to a piece of audio equipment – it can be instantly ‘read’ and played. Compressed data has been previously ‘packaged’, or squashed down to save space on the disc. Compressed data must be Decompressed (or “decoded”) in order to be ‘read’ – like boxing up your book collection when you move, you must unpack your books before you can read them again. PCM is different. Since the data has not been ‘boxed up’, it does not have to be ‘unboxed’ (or “decoded”) before it is usable. See Compression.

[B]Perforated Matte White Front Projection Screen[/B]

This screen is perforated with thousands of small holes to allow sound to pass through the screen material. For screening rooms with seating less than 20’ from the screen, this screen is not recommended because the holes will be visible during projection. A micro perforated screen is available for fewer than 20’.

[B]Phosphor Burn-in[/B]

Colloquially known as screen burn, is a permanent disfigurement of areas on an electronic display.

[B]Pillar Box[/B]

The pillar box effect occurs in widescreen video displays when black bars (mattes or masking) are placed on the sides of the image.


A single point on a computer display. In a CRT monitor, each pixel is a blend of red, green, and blue phosphor dots that are activated by electron guns. In a LCD monitor, each point in the display grid constitutes a pixel. The term is a contraction of picture element.

[B]Pixel Buffer[/B]

A part of the Blu-ray player’s memory that renders graphical elements before they’re displayed.

[B]Pixel Density[/B]

is the actual amount of physical picture elements on a screen surface or an LCD/DLP projection chip. LCD/DLP projectors have a fixed number of pixels on their chips. With reference to Video, the higher the native pixel count, the higher the resolution capability of the video display device. A native pixel count of 1024x768 (1,024 pixels across vs 768 pixels down) is sufficient for DVD. However, 720p HDTV signals require a 1280x720 pixel count to give you a one-for-one signal representation, while a 1080i HDTV input signal needs a native pixel count of 1920x1080 for a one-for-one representation of the 1080i signal.

[B]Pixel Response Time[/B]

[COLOR=DarkGreen]The time it takes for a pixel to switch from active to inactive. Slow response time, more than 16 milliseconds, results in motion trails following fast moving objects on screen.[/COLOR]


Pixelation occurs when a monitor doesn’t have enough video memory to enable it to render graphics properly. The result is that you can see individual pixels: the graphics have jaggy edges.

[B]Plasma Display Panel[/B]

An emissive flat-screen technology in which ionized gas is sandwiched between panels of glass that are embedded with wire. The wires meet at right angles, creating pixels. Images are created by sending an electrical current through selected intersections, causing the gas to break down at those points and produce plasma discharges that excite nearby phosphors and cause them to glow. These displays are slim (about 4 inches deep) and can be created in sizes as large as 60 inches diagonally; they are generally used in flat-panel TVs.


An aperture in a loudspeaker enclosure that helps extend the usable low-frequency output. A ported enclosure is also called vented or bass reflex.


Occurs when the color depth, sometimes called bit depth, is insufficient to accurately sample a continuous gradation of color tone. As a result, a continuous gradient appears as a series of discrete steps or bands of color — hence the name. When discussing fixed pixel displays, such as LCD and plasma televisions, this effect is also referred to as false contouring.

[B]Progressive Scan[/B]

A method of displaying images on a CRT monitor or a high-definition TV in which all the lines of a picture are drawn in one quick burst, from left to right and from top to bottom. Compare this to interlacing, in which every other line is displayed in two successive swoops to form a complete picture.


A projection unit, typically DLP or LCD, that projects an image on a wall or screen. Projectors are much smaller than standard display units and can create various screen sizes depending on distance from the screen. Until recently most HDTV projectors were 720p capable; 1080p units are now available.

[B]PSIP: Program and System Information Protocol.[/B]

A part of the ATSC digital television specification that enables a DTV receiver to identify program information from the station and use it to create easy-to-recognize electronic program guides for the viewer at home. The PSIP generator inserts data related to channel selection and electronic program guides into the ATSC MPEG transport stream.


Personal video player. Portable device designed to play back video files from a hard drive; may or may not include a small LCD screen.


Personal video recorder.



The magnification or resonance factor of any resonant device or circuit. Also the width of affected frequencies in an equalizer. Shaped somewhat like an adjustable width bell curve.


Quadrature Amplitude Modulation. Type of digital cable tuner. Televisions and other products equipped with QAM tuners can tune unscrambled digital cable channels from some cable providers, but to view scrambled channels a CableCard is required.

[B]Quadrature Phase Shift Keying[/B]

A digital frequency modulation technique used for sending data over coaxial cable and digital satellite networks. Since it’s both easy to implement and fairly resistant to noise, QPSK is used primarily for sending data from the cable subscriber upstream to the Internet.


[B]Rainbow Effect[/B]

A visual artifact that occurs in single-chip DLP displays, caused by the fact that the single DLP chip uses a color wheel to create red, green, and blue, and hence all colors. Occurs primarily when the eye looks across the screen or when adjacent areas of very dark and very light material move quickly. The occurrence of these rainbows has been significantly reduced with the advent of newer, faster color wheels, and most people who watch a DLP never see rainbows at all–and the few who do, usually see them only occasionally.

[B]Rear Projection[/B]

TV system where the picture is projected onto the rear of a translucent screen via a series of mirrors and viewed as you would an average television.

[B]Red Push[/B]

Tendency of the color decoder in many TVs to accentuate the color of red compared to blue and green. Red push is typically introduced intentionally to compensate for an overly blue color temperature.

[B]Refresh Rate[/B]

The maximum number of times per second that a monitor can redraw an image. The refresh rate, expressed in hertz (Hz). The higher the refresh rate, the easier the monitor is to view; rates lower than 75Hz can produce irritating screen flicker.


A measurement of the finest (smallest) detail that is visible, or can be resolved, in a video image. TV Resolutions may be expressed as “number of pixels” in an image; or more commonly, "As Total Number of (horizontally scanned) Lines used to create the image.

While a TV’s Resolution can be influenced by the number of pixels in the image, it is important to note that the pixel numbers do not define ultimate resolution; ONLY the resolution of that part of the equipment. Many other variables must be taken into account - such as, the quality of lenses, display tubes, film process and film scanners, etc. used to produce the image on the screen - as well as what measurement-methods are used.

[B]Resonant Frequency[/B]

The frequency at which any system vibrates naturally when excited by a stimulus. A tuning fork, for example, resonates at a specific frequency when struck.

[B]Return Loss[/B]

The ratio of signal power transmitted into a system, to the power reflected or returned. This is like an echo that is reflected back by impedance changes in the system.

Variation in impedance from the source results in some returned signal. Cabling systems lack perfect impedance structure and matching, and have a measurable return loss. At every connection, the potential exists that the impedance will change, resulting in part of the signal being reflected back to the source. Each impedance change contributes to signal loss (attenuation) and directly causes return loss.


The reflections of sound within a closed space.

[B]Reverberation Time[/B]

The amount of time it takes the reverberation to decay 60 dB from the level of the original sound.


The abbreviation for red, green and blue signals, the primary colors of light (and television). Cameras and telecines have red, blue and green receptors, the TV screen has red, green and blue phosphors illuminated by red, green and blue guns. Much of the picture monitoring in a production center is in RGB. RGB is digitized with 4:4:4 sampling which occupies 50 percent more data than 4:2:2.

[B]Ribbon Speaker[/B]

A loudspeaker that consists of a thin, corrugated, metallic ribbon suspended in a magnetic field. The ribbon acts electrically like a low-impedance voice

coil and mechanically as a diaphragm.



Refers to the amount of color in a picture. Zero saturation results in a black-and-white picture, while too much saturation results in garish colors.


Circuitry or device that converts a video signal to a resolution other than its original format. Scaling can involve upconversion or downconversion, and may also include a conversion between progressive- and interlaced-scan formats. A scaler can be built into a TV, an HDTV set-top box, a DVD player, or another video source, or it may be a standalone component.

[B]Scan velocity Modulation (SVM)[/B]

TV feature; a circuit that increases the speed of electrons to their respective phosphor dots. Often produces an artificial “hard edge,” which is why it should be switched off for sources such as DVD and HDTV. Used in professional projectors as a form of dithering to reduce the visibility of scan lines. Also called velocity scan modulation or, generically, edge enhancement.


Standard-definition television. Digital television format that includes 480-line resolution in both interlaced (480i) and progressively scanned (480p) formats; offers discernible improvement over conventional analog NTSC picture resolution, with less noise; similar to DVD or satellite TV quality but not considered high-definition television (HDTV).


Sequential Couleur Avec Mémoire, Also called Système Électronique Couleur Avec Memoire, or sequential color with memory. Analog color television broadcast standard developed in the mid-1960s and used in France, its former possessions, and some eastern European countries, including former members of the Soviet Union; offers 819 lines of horizontal resolution. SECAM is one of three main television standards; the other two are NTSC and PAL.


Surface-Conduction Electron-Emitter Display, A display technology developed by Toshiba and Canon that uses phosphors activated by an electron emitter, just as standard CRT tube televisions do. Supposedly, the result is tube-level picture quality in a flat form factor. SED TVs are not yet available, but the partners claim these TVs will offer low power consumption, fast response time, and high resolution.

[B]Selectable Aspect Ratios[/B]

TV feature, especially on a wide-screen and/or digital model, that allows the adjustment of screen proportions for the material being viewed; an image can be adjusted to fill the screen or to have blank bands placed at the top and bottom of a wide-screen image, or the left and right for a 4:3 image on a wide-screen set.

[B]Selectable Color Temperature[/B]

Large-screen TV feature, especially a high-end set, that allows the adjustment of the color temperature.

[B]Signal-to-Noise Ratio[/B]

A signal to noise level comparison, used to measure the clarity of a signal.


Simsub, or Simultaneous substitution is the practice by which cable, direct broadcast satellite and multichannel multipoint distribution service television distribution companies substitute a local or regional signal over a foreign or non-local signal, when two or more stations are airing the same programming at the same time. It is sometimes erroneously referred to as “simulcasting”; that term refers to the simultaneous broadcast of a program over two channels, regardless of whether or not there is signal replacement.

An interest, either of civic/national pride, or of protecting smaller commercial interests, is usually involved. The practice has close similarities between Canada and the United States.


Full-color displays are made by combining red, green, and blue light in varying degrees to produce different shades of colors. In a display with a fixed pixel structure, such as LCDs or plasma panels, the red, green, and blue light comes from adjacent cells in the display’s physical structure. The light from these three subpixels–one for each color–combine to create a single pixel. There are also pixel structures that do not rely on three subpixels.


A specialized speaker that reproduces sound from the lower frequencies of the audible spectrum, usually below 80Hz.

[B]Surround Sound[/B]

A system for recording and reproducing sound that involves three or more channels and speakers. Such a system creates an environment in which the speaker is effectively surrounded by sound sources. In addition to being used in movie theaters, this type of arrangement is now available in the home. Surround-sound systems are available in digital and analog versions. Digital surround sound uses the 5.1 format to record sound. Dolby Pro Logic technology is used for analog surround sound.[U][B]3.0 Channel Surround (analog matrixed: Dolby Surround)[/B][/U]

Extracts 3 audio channels from a specially encoded two-channel source:

 * Two channels for speakers at the front—left (L) and right (R).
 * One channel for surround speaker or speakers at the rear—surround (S).
 * Describes the numerous matrixed (pre- Pro Logic) surround processors.

Placement: (three speakers in total) Three identical speakers placed equidistant around a central listening position. If two rear speakers are used they should also be placed above ear height, slightly behind the listening position, and should be of bi-polar construction.

[U][B]4.0 Channel Surround (analog matrixed/discrete: Quadraphonic)[/B][/U]

Extracts four audio channels from either a specially encoded two-channel source or a four-channel source:

 * Two channels for speakers at the front—left (L) and right (R).
 * Two channels for surround speakers at the rear—surround left (LS) and surround right (RS). Some newer receivers support the LFE channel.
 * Describes the early matrixed systems and discrete Quadraphonic surround systems. Source media, usually LP record or tape, is often branded four channel stereo.

Placement: Quadraphonics is a system designed for music only. All speakers should be at an ±45˚. All speakers should be above ear height.

[U][B]4.0 Channel Surround (analog matrixed: Dolby Pro Logic)[/B][/U]

Extracts four audio channels from a specially encoded two-channel source:

 * Two channels for speakers at the front—left (L) and right (R).
 * One channel for speaker at the center—center (C).
 * One channel for both surround speakers at the rear—mono surround channel (S).
 * Describes the Dolby Pro Logic matrixed surround system. Source media, usually VHS, Laser Disc, television broadcast or CableTV/Satellite is often branded with "Dolby Surround" logo. This is the encoding used on the analog optical track for theatrical motion picture films.

Placement: (Five speakers in total) The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a TV, and as close to ear-high as possible. Surround channel speakers should be placed above ear height, slightly behind the listening position, and should be of bi-pole construction.

[U][B]5.1 Channel Surround (3-2 Stereo) (analog matrixed: Dolby Pro Logic II)[/B][/U]

Extracts Five audio channels from either a specially encoded two-channel or a stereo source:

 * Two channels for speakers at the front—left (L) and right (R).
 * One channel for speaker at the center—center (C).
 * Two channels for surround speakers at the rear—surround left (LS) and surround right (RS).
 * One low-frequency effects channel (LFE).
 * Describes the Dolby Pro Logic II matrixed surround system. Source media is often gaming systems including Playstation 2, GameCube and Wii games branded with "Pro Logic II" logo.

5.1 surround sound may also be referred to as 3-2 stereo. This defines the configuration that has been standardised for numerous surround sound applications. The term 3-2 refers to 3 front speakers and 2 rear speakers.

Placement: 5.1 speaker layouts should conform to the ITU-R BS.775 standard, despite the myth that music and video content require different placements. The ITU standard states that the left and right speakers are located at ±30Ëš, while the rear speakers should be positioned approximately ±110Ëš. There is speculation that rear loudspeakers at ±150Ëš provide “more exciting surround effects”.

[U][B]5.1 Channel Surround (70 mm 6-Track) (analog magnetic)[/B][/U]

Delivers six audio channels from a 6 channel source:

 * Four channels for speakers at the front-left (L), left center (LC), right center (RC), and right (R).
 * One channel for speaker at the center-center (C)
 * One channel for surround speaker at the rear-monaural surround (S)

[U][B]5.1 Channel Surround (3-2 Stereo) (analog magnetic: Dolby Stereo “Baby Boom”)[/B][/U]

Delivers five audio channels and 1 LFE channel from a 6 channel source:

 * Two channels for speakers at the front—left (L) and right (R).
 * One channel for speaker at the center—center (C).
 * Two channels for surround speakers at the rear—surround left (LS) and surround right (RS).
 * One low-frequency effects channel (LFE).

[U][B]5.1 Channel Surround (3-2 Stereo) (digital discrete: Dolby Digital, DTS, SDDS)[/B][/U]

Delivers Five discrete audio channels and 1 LFE channel from a 6 channel source:

 * Two channels for speakers at the front—left (L) and right (R).
 * One channel for speaker at the center—center (C).
 * Two channels for surround speakers at the rear—surround left (LS) and surround right (RS).
 * One low-frequency effects channel (LFE).
 * Describes the Dolby Digital, Digital Theater System (DTS), and Sony Dynamic Digital Sound (SDDS) systems. Source media, usually DVD and sometimes Laser Disc or satellite/digital cable is often branded with "Dolby Digital" and/or DTS logos.
 * DTS uses a higher data rate than Dolby Digital, so DTS can achieve higher fidelity.   

5.1 surround sound may also be referred to as 3-2 stereo. This defines the configuration that has been standardised for numerous surround sound applications. The term 3-2 refers to 3 front speakers and 2 rear speakers.

Placement: 5.1 speaker layouts should conform to the ITU-R BS.775 standard, despite the myth that music and video content require different placements. The ITU standard states that the left and right speakers are located at ±30Ëš, while the rear speakers should be positioned approximately ±110Ëš. There is speculation that rear loudspeakers at ±150Ëš provide “more exciting surround effects”.

[U][B]5.2 Channel Surround (3-2 Stereo) (digital discrete: Dolby Digital, DTS, SDDS)[/B][/U]

Same as above with addtional subwoofer.

[U][B]6.1 Channel Surround (analog matrixed: Dolby Pro Logic IIx)[/B][/U]

Extracts six audio channels and one low-frequency channel from either a specially encoded two-channel or stereo source. Expands a back surround channel from a 5.1 channel source:

 * Two channels for speakers at the front—left (L) and right (R).
 * One channel for speaker at the center—center (C).
 * Two channels for surround speakers at the sides—side left (LS) and side right (RS).
 * One channel for surround speakers at the rear—back surround channel (BS).
 * One low-frequency channel to drive a sub-woofer.
 * Describes the Dolby Pro Logic IIx matrixed surround system. Source media is the same as both Dolby Pro Logic and Dolby Pro Logic II.

Placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location. The center speaker should be placed behind the screen (when using projection) or over or under a TV. Side channel speakers should be placed to the left and right of the listening position, equidistant from the front speakers and the rear speakers. Rear channel speakers should be placed slightly behind the listening position, and should have a normal high-quality monopolar construction. Front speakers should be at ear height and surrounds should be above.

[U][B]6.1-7.1 Channel Surround (digital partially discrete: Dolby Digital EX)[/B][/U]

Delivers five audio channels, one extracted audio channel and one LFE channel from a six channel source:

 * Two discrete channels for speakers at the front—left (L) and right (R).
 * One discrete channel for speaker at the center—center (C).
 * Two channels for surround speakers at the sides—left surround (LS) and right surround (RS). The discrete LS and RS channels are dematrixed into LS, RS, and back surround (BS).
 * One channel for surround speakers at the rear—back surround channel (BS). The back surround channel can be made into two channels by the receiver.
 * One low-frequency effects channel (LFE).
 * Describes the Dolby Digital EX discrete/matrixed hybrid Surround system. Source media, usually DVD is often branded with "Dolby Digital EX" logo. This format is used in some theatrical motion picture films.

Placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location. The center speaker should be placed behind the screen (when using projection) or over or under a TV. Side channel speakers should be placed to the left and right of the listening position, equidistant from the front speakers and the rear speakers. Rear channel speakers should be placed slightly behind the listening position, and should have a normal high-quality monopolar construction. Front speakers should be at ear height and surrounds should be above ear height.

[U][B]6.1 Channel Surround (digital discrete: DTS-ES)[/B][/U]

Delivers six discrete audio channels and 1 LFE channel from a seven channel source:

 * Two channels for speakers at the front—left (L) and right (R).
 * One channel for speaker at the center—center (C).
 * Two channels for surround speakers at the sides—side left (LS) and side right (RS).
 * One channel for surround speakers at the rear—back surround channel (BS).
 * One low-frequency effects channel (LFE).
 * Describes the DTS ES discrete Surround system. Source media, usually DVD is often branded with "DTS ES" logo. In theatrical motion picture film, this format does not exist, and the name "DTS-ES" refers to the above hybrid format used for Dolby Digital EX.

Placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location. The center speaker should be placed behind the screen (when using projection) or over or under a TV. Side channel speakers should be placed to the left and right of the listening position, equidistant from the front speakers and the rear speakers. Rear channel speakers should be placed slightly behind the listening position, and should have a normal high-quality monopolar construction. Front speakers should be at ear height and surrounds should be above ear height.

[U][B]6.1 Channel Surround (analog magnetic) Cinerama 7-Track[/B][/U]

Delivers seven audio channels from a 7 channel source:

 * Four channels for speakers at the front-left (L), left-center (LC), right-center (RC), and right (R).
 * One channel for the center (C)
 * Two channel switchable surround that could feed one channel on the left and right walls and the other in the rear or could feed one channel on the left and one on the right.

Placement: The first five speakers should be placed across the wall on top of the screen or behind the screen. There should be three surround channels on the left, right, and rear walls. Switchable surround sound was done manually by a theater engineer based upon cue marks.

[U][B]7.1 Channel Surround (digital discrete: Dolby Digital Plus, DTS-HD, Dolby TrueHD)[/B][/U]

Delivers seven audio channels and one LFE channel from an 8 channel source:

 * Two channels for speakers at the front—left (L) and right (R).
 * One channel for speaker at the center—center (C).
 * Two channels for surround speakers at the sides—left surround (LS) and right surround (RS).[7]
 * Two channels for surround speakers at the rear—left back (LB) and right back (RB).
 * One low-frequency effects channel (LFE).
 * Describes the Dolby Digital Plus discrete Surround system. Source media, usually Blu-Ray and sometimes HD DVD is often branded with "Dolby Digital Plus" and/or "DTS-HD" logos.

Layout variation for 7.1 widescreen cinema format:

 * Four channels for speakers at the front—left (L), Center-left (CL), right (R) and Center-Right (CR).
 * One channel for speaker at the center—center (C).
 * Two channels for surround speakers at the rear—surround left (LS) and surround right (RS).
 * One low-frequency effects channel (LFE).

This variation is becoming increasingly popular in home entertainment systems, as well as for large cinema auditoria where the screen width is such that the additional channels are needed to cover all angles between the loudspeakers satisfactorily for all seats in the auditorium.[8]

For music, speaker placement is unknown.

Placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a TV, and as close to ear height as possible. Side channel speakers should be placed on side walls, to the left and right of the listening position, equidistant from the front speakers and the rear speakers. Rear channel speakers should be placed on side walls, slightly behind the listening position, and should have a normal high-quality monopolar construction. Front speakers should be at ear height and surrounds should be above ear height.

[U][B]7.2 Channel Surround (digital discrete: Dolby Digital Plus, DTS-HD, Dolby TrueHD)[/B][/U]

Same as above with addtional subwoofer.

[U][B]10.2 Channel Surround[/B][/U]

10.2 is the surround sound format developed by THX creator Tomlinson Holman of TMH Labs and University of Southern California (schools of Cinema/Television and Engineering). Developed along with Chris Kyriakakis of the USC Viterbi School of Engineering, 10.2 refers to the format’s promotional slogan: “Twice as good as 5.1”. Advocates of 10.2 argue that it is the audio equivalent of IMAX.

10.2 augments the LS (left surround) and RS (right surround) channels by two point surround channels that can more finely manipulate sound—allowing the mixer to shift sounds in a distinct 360° circle around the movie watcher.

The 14 discrete channels are:

 * Five front speakers: Left Wide, Left, Center, Right and Right Wide
 * Five surround channels: Left Surround Diffuse, Left Surround Direct, Back Surround, Right Surround Diffuse and Right Surround Direct
 * Two LFE channels: LFE Left, LFE Right
 * Two Height channels: Left Height, Right Height

The .2 of the 10.2 refers to the addition of a second subwoofer. The system is bass managed such that all the speakers on the left side use the left sub and all the speakers on the right use the right sub. The Center and Back Surround speaker are split among the two subs. The two subs also serve as two discrete LFE (Low Frequency Effects) channels. Although low frequencies are not localizable, it was found that splitting the bass on either side of the audience increases the sense of envelopment.

[U][B]22.2 Channel Surround[/B][/U]

22.2 is the surround sound component of Ultra High Definition Video (Super Hi-vision TV with 4320 scanning lines), and has been developed by NHK Science & Technical Research Laboratories. As its name suggests, it uses 24 speakers. These are arranged in three layers: A middle layer of ten speakers, an upper layer of nine speakers, and a lower layer of three speakers and two sub-woofers. The system was demonstrated at Expo 2005, Aichi, Japan, the NAB 2006 conference, Las Vegas, and at IBC 2006 and IBC 2008, Amsterdam, Netherlands.[B][U]T[/U][/B]

[B]Tactile Transducer[/B]

A device that implements home theater audio by transmitting ultra-low bass frequencies in such a way that the sound waves are felt but not heard. Tactile transducers are typically mounted beneath home theater seating, and transfer vibrations directly into the furniture, so that anyone viewing a movie will not only see and hear the film, but will be able to feel it as well.

[B]Temporal Artifact[/B]

In a digital video image, a picture imperfection that occurs over several frames, often in smooth-textured areas and around high-contrast edges of moving video objects. Similar to spatial artifacts, both often referred to as mosquito noise.

[B]Temporal Resolution[/B]

One of two possible ways to measure resolution in a video image; the other is spatial. Describes the amount of picture detail in a moving image, measured by the number of lines of resolution delivered over a given period of time. When an image moves rapidly, a 720p HDTV display will provide more picture information than a 1080i HDTV display because progressive scan produces twice as many frames in the same period of time as 1080i.

[B]Terrestrial Broadcast[/B]

Standard over-the-air broadcasts, as opposed to satellite or cable transmission.

[B]THD- Total Harmonic Distortion[/B]

Expressed as a percentage, it is the measurement of distortion caused by an electronic component related to the harmonics it generates relative to a fundamental frequency.

[B]Throw Distance[/B]

Throw distance is the measurement from the projector’s lens to the screen. A projector with a zoom lens will have a range of throw distances for any given image size, while a projector without a zoom lens will only be able to project one image size at a given distance from the screen. In Projector Central’s articles, throw distance is normally quoted for a 100" diagonal screen.

[B]THX - Tom Holman’s eXperiment[/B]

A certification for audio equipment and installation done to a standard set by THX Ltd., a company owned by George Lucas. Usually geared towards audio playback for video and cinema.

[B]THX Select[/B]

THX certification for speakers, receivers and DVD players designed for small to medium sized home theaters and non-dedicated rooms of around 2000 cubic feet and performing to a specified standard.

[B]THX Select 2[/B]

THX certification specifically for receivers to a specified standard.

[B]THX Ultra[/B]

Certification program for speakers, receivers, amplifiers and interconnects that are not room size dependent and performing to a specified standard.

[B]THX Ultra 2[/B]

THX certification for speakers, receivers, controllers, DVD players for dedicated home theaters of about 3000 cubic feet which perform to a specified standard.


A type of digital connection that uses optical signals to send a signal flawlessly, without losing any information. It’s used for connecting MiniDisc players to stereos and certain sound cards.

[B]A work in progress

This Glossary is a concise collection of some of the terminology that you may confront; it is not intended to be a complete compendium of technical terms.


[B]Unbalanced Connection[/B]

Connection method in which the audio signal is carried on two conductors, called signal and ground. Contrasted with balanced connection, in which the audio signal is carried on three conductors.


In loudspeakers, woofer movement after the drive signal has stopped.

[B]Undemodulated Dolby Digital[/B]

A method of storing Dolby Digital that doesn’t require modulation to accommodate the laserdisc format. All Dolby Digital signals except those stored on laserdisc are unmodulated.


Even distribution across a given space. In video, uniformity can refer to the distribution of light (hot spotting) or color.

[B]Unity Gain[/B]

Output that equals the input. Unity gain screen material reflects as much light as the reference material. Has an even dispersion of light.


In DTV, the conversion from a lower-resolution input signal to a TV capable of displaying higher resolutions, such as from an SDTV 480p signal to an HDTV 1080i native display.


Technique of increasing the sampling frequency of a digital audio signal so that it can be converted to analog from the higher frequency.


A sound having too much treble and not enough bass.

[B]Usable Sensitivity[/B]

Tuner specification that states the voltage across the antenna required to produce an audio signal with a signal-to-noise ratio of 30dB. Contrast with the more stringent quieting sensitivity.



The volume of air that offers the same degree of restoring force on the loudspeaker driver’s cone as that of the cone’s suspension.

[B]Vertical Compression[/B]

Feature found on 4:3 TVs designed to take advantage of the extra resolution in anamorphic DVDs and other wide-screen content. Pioneered by Sony, this feature squeezes the TV raster so that the electron beam scans in a smaller area. It requires setting the DVD player to 16:9 mode, eliminates anamorphic downconversion artifacts, and ideally provides a 33 percent increase in resolution in the letterboxed image.
Vertical Frequency[/B]

In television, the number of vertical fields per second measured in hertz. NTSC has a vertical frequency of 60Hz, where as PAL has 50Hz.

[B]Vertical Resolution[/B]

The number of horizontal lines (or pixels) that can be resolved from the top of an image to the bottom. (Think of hundreds of horizontal lines or dots stacked on top of one another.) The vertical resolution of the analog NTSC TV standard is 525 lines. Some lines are used to carry other data such as closed-captioning text, test signals, and so on, so we end up with about 480 lines in the final image. All of the typical NTSC sources, including VHS VCRs, cable, and over-the-air broadcast TV (analog), non-HD digital satellite TV, DVD players, camcorders, and so forth, have a vertical resolution of 480 lines. DTV signals have vertical resolution that ranges from 480 lines for SDTV, to 720 or 1,080 lines for HDTV.

[B]Voice Coil[/B]

Coil of wire inside a loudspeaker driver through which current from the power amplifier flows.


Speakers that are “voice-matched” have the same timbre or tonal quality. Voice-matched speakers in a home theater system will result in a convincingly seamless encompassing sound.


[B]Wall-stud Resonance[/B]

Acoustic resonance of a listening rooms walls when struck by sound. Occurs only in drywall-on-stud construction.


Usually refers to a sound quality that results from not having more than the natural amount of treble. The opposite of “bright”.
Weighting Curve[/B]

A filter applied to noise or sound-pressure level measurements that approximates the perceived loudness or noise level.

[B]White Front Projection Screen[/B]

White is the most common color for a screen because it allows the highest volume of light to reflect off the screen.

[B]White Level[/B]

More commonly called contrast. The proper setting for contrast is 12 to 20 foot lumens. If you don’t have a meter handy, then turn the contrast way down and then back up to the point where white appears white. Most TVs are shipped with the contrast set too high.


Image with an aspect ratio greater than 1.33:1 or a picture wider and narrower than a standard television image. Typically refers to TVs in the 16:9 aspect ratio.

[B]Windowbox Bars[/B]

The blank bars on the left and right of a 4:3 image when displayed on a wide-screen 16:9 display. They can often be adjusted in intensity from black to gray; gray bars help exercise CRT and plasma displays more evenly across the screen.



An intentional roll-off in a theatrical system’s playback response above ~2kHz at 3dB per octave. A modern convention (standardized between 1975 and 1984) specified in ISO Bulletin 2969, it is measured at the rerecording position in a dubbing stage or two-thirds of the way back in a movie theater. Pink noise should measure flat to 2kHz and then should roll-off above that. Home THX processors add this roll-off, when engaged, so that a home video soundtrack will have the same response as it would in a theatrical setting.


The maximum linear cone excursion of a driver, measured in inches or millimeters.


[B]Y Pb Pr[/B]

Luminance, two chrominance channels of blue minus luminance, red minus luminance. Technical shorthand for component video.

[B]Y Cb Cr[/B]

Luminance, two chrominance channels of blue minus luminance, red minus luminance. Technical shorthand for component video.

[B]Y R-Y B-Y[/B]

Luminance, two chrominance channels of red minus luminance, blue minus luminance. Technical shorthand for component video.



To make an area of an image larger.

[B]Zoom Lens[/B]

Usually a lens with a long focal length that allows the camera operator to move his view in on progressively smaller portions of the currently visible scene and subsequently move his view back out and view the entire scene. Only the lens moves; the operator remains stationary.

[B]Zoom Range[/B]

The distance range for the placement of a video projector. The greater the distance from the screen, the larger the image. However, not all projectors yield the same image size at the same distance, so selection of a projector should be based upon the manufacturer’s statement of the image vs: distance ratio.

[B]Zoom Ratio[/B]

Is typically stated in a range of screen width/projection and distance.


One or more rooms powered by one or more amplifiers, which are all fed by one source. A home can be divided into multiple zones, which can play multiple sources, even though several rooms (say, the kitchen, dining room, and living room) all play the same source.