Audible differences between different CD-R media used for audio?

Blank Media
#21

I’ll take that thought a step further. ANY listening tests are suspect. Just try doing it yourself and you’ll see how fast you become overloaded and confused.

The only testing that has meaning would be done with scopes, spectrum analyzers and the like, and be free of any human perceptions. There are no audible anomalies that cannot be measured, whether it’s harmonics, clipping or any kind of distortion. And it should be measurable in the line signals before it ever reaches a speaker.

IMHO, even double blind listening tests are poor “science”, and their only purpose would be to prove or disprove that a measurable anomaly can be heard.

Medical science has been grappling with human perceptions for a long time, and the best research available in that area suggests that 40% of people will report changes in perceptions even in the absense of any intervention. If you apply that to listening tests, 40% of people will report differences when there are none.

Add to that the multitude of small physical changes that can affect our hearing, like body temperature, a slight tilt of the head or any change of body position, visual perceptions, and the list goes on.

#22

Yes there is absolutely a limit to how long you can concentrate really hard on hearing minuscule differences in audio material. Personally I’m exhausted after an hour of doing listening tests.

That’s a nice theory, but unfortunately it is not completely understood what kind of differences should be measured, so in practice you cannot avoid using human listeners for determining whether high-end audio sounds as it should.

It’s not bad science if the statistical methods used are valid. Measuring whether an anomaly can be heard (with statistical significance) is EXACTLY what scientific listening tests are used for since this cannot be done by non-human equipment. You may call it “poor” science, but that’s a moot point since it is the only science available!

I wouldn’t know about the 40% but there is certainly many that will do so, perhaps because it unconsciously makes many people feel better to be “able” to hear a difference rather than admitting “defeat” in not being able to hear it.

That still doesn’t mean that it is impossible to conduct a double-blind listening test and draw statistically valid conclusions from it.

#23

Sorry, but if 40% of listeners will report a difference when there is none, (or even 25%), then the value of any such listening tests is dubious. The most likely outcome of any properly run double blind will be to prove that listening tests do not produce “statistically significant” results at all. All you are documenting is a statistical representation of personal perceptions, which means nothing. A properly run test would include random examples of identical material to be compared, and this will provide a percentage of listeners who report a difference when there is none. If the final results are less than or close to this figure, then the whole test is thrown out. If this percentage of false positives varies greatly from one test sample to another, then you’ve got big problems again.

You can argue statistics all day, but you’re still trying to measure that which cannot be measured. But if makes someone happy to use a specific brand of CDR because it sounds better, I don’t think anyone will really care. Proclaiming that that media brand is “better” because of that is another matter altogether.

#24

Wow, terrific find, Francksoy. Thanks for the link.

#25

Just a quicky …

Can anyone hear the little squeaking noises that some drives make when they read certain CDR/DVDR discs?
How about the buzz that most AC/DC adapters make?

If you can’t hear it, it won’t affect you.
Those of us with sensitive hearing can hear the TV buzzing when it’s muted or even in standby, can hear the hum from ac->dc converters and can hear the disc (hitting the heads?) while reading.

Of course reading the data back from a two different reliable brand CDR’s isn’t gona make a difference, as they are doing their job properly. Obviously a crap cd is gonna be worse, because anyone with sensitive hearing can hear the players motor crapping itself rewinding the head for re-reads, and the motor spinning the discs accelerating/decelerating after an error. How about the noise created on the power line, affecting the amp, hence coming through your speakers as the drives motor changes speed?

There are many things which I might point out cannot easily be verified by anyone over the age of 30, as most scientists agree that human hearing deteriorates with age. Those high frequency noises which really spoil your enjoyment of your music simply cannot be picked up anymore. Please state what percentage of “Experts” are under 30?

That said, I still can’t hear any reasonable difference between CDR brands. Cheap CDR’s cause issues (as stated above) which DOES NOT EFFECT the audio playback, if the player is a good brand and is doing it’s job properly and the output is filtered.
On cheap players/systems, the CDR does make a difference, as read issues cause noise.

#26

Did you read the test linked by Francksoy above? They included an anonymous copy of the reference disc numbered randomly, so that they could measure how many listeners proclaimed to hear the difference between two identical discs, and also how different it was rated. I don’t think it’s fair to imply that all listening tests are performed in a flawed and invalid fashion. At least it seems to me that this is what you are implying?

#27

ok i can understand people claiming that records (analog sound) have differences, non digital tape also, but cd’s??? come on they are 0’s and 1’s there is no tonal difference from this 1 to that 1. the only difference you might here is due to the fact that CD-A has no error correction like data cd’s have so the reading drive has to interpolate if it is unable to read… and we have all heard the difference… It sounds like a skip or a click.

there is plainly no other way the music can change. all of the sound characteristics are 0 and 1 which do not change when burned to any media.

sound is a force (wave motion) which can be completely quantified so show me some sound scans that demonstrate a difference rather than psychosomatic imagined differences. until then this is as true as the tabloids. :rolleyes:

#28

:iagree: totally, with the assumption that mechanical devices are not used to read the data.
However, mechanical devices are used to read the data, hence the practical retrieval of data is subject to imperfections and the mechanical devices can generate electrical noise which can affect cheap amplifiers (which of course is not apparent on well maintained professional audio equipment), and the resultant reconstruction of sound will be imperfect.
Different reflectivity / different writers can, and do affect players (mostly cheap players) ability to read back data from a disc.

Sound scans would need to to cover a very broad frequency band between 0->92Khz to be at all relevant as low frequencies can be felt, if not heard and can affect a users perception. Similarly, high frequency noise, put through a 44.1Khz Filter may result in lower frequency noise!

#29

Dont forget that after the DAC the data is analog. There can still be noise affecting the data which then can not be corrected. So the 1 and 0 can be 100% read with no difficulties but that does not say that the sound can not be different.

I just stumbled accross and read an article in a Japanese Audio Mag (about 4 years old) where a respected Univ. Professor stated that when reading CD-Rs of different make the laser power used to read is different. It is also different compared to Pressed Discs. He also states that different discs have different weight (printables/non-printables etc) and that the player needs more power to rotate the disc the more weight the disc has. Focusing is different on all CD-R types too. So the bottom line is that power used to read the disc by the player changes with different discs (ex: power used to read TY is not the same as the power used to read CMC discs). He then goes on and says that most cheap players (1 box players) have bad designed PCBs and that the noise on the power line influences/distorts the analog data leading to different sound. That he says is why with high end systems with a good PCB design and/or external power supply the difference in sound can not be heard or only slightly. He writes that portables or players with Radio, clock etc integrated (those called CD boom box or ghetto blaster) are much more affected because they have many noise sources which can distort the analog part.
This article was written with the assumption that there are no reading errors during playback nor faulty discs.

For me this explanation sounds reasonable since noise interference leads to bad radio signals, slow ADSL/Modem connection speeds etc. So if a AM radio signal can interfere with ADSL lines and thus causing slow speeds (or even causing the conection to break down) the possibility of noise inside a CD Player interfering with the analog sound after the DAC seems logical to me.
Just my 2cents regarding cnlson’s post above

#30

Deja Vu?

#31

Yes, well - i think that’s true that mechanical parts can cause noise on the rails affecting the amplifiers, but if the supply was adequate/filtered this would not be a problem. I don’t think that designers of even cheap players are that incompetent as basic regulation/filtering is not that expensive. Maybe the noises coming from the laser deck (lower amplitude) don’t affect the sound as much (i did notice the deck produces noise during read because of the electronics involved) but I would think the supply would not be so badly affected to cause a SIGNIFICANT difference in sound quality.

#32

I am also skeptical that there are reliably-percieved differences between CD-R brands or between different runs of pressed CDs.

However, it’s not true that CD-A contains no error correction; in fact, even CD-A contains multiple levels of parity checks (called Reed-Solomon codes) that can detect errors in and (in almost all cases) perfectly reconstruct the digital data stream. In practice, the data stream from even a clean, well-made CD will require some of this error correction (these are the C1 and C2 errors familiar from quality scans). But with a clean, well-made disc, the player will only resort to interpolation very rarely or not at all.

It’s true that data CDs contain an extra layer of error correction, above and beyond those used on data CDs, since a click in your music is an annoyance, but a click in your data is a disaster.

#33

My own experience in the embedded electronics field would indicate that as far as the money men are concerned, there’s no such thing as too cheap. If they can save $0.25 per unit by eliminating a component that’s not absolutely necessary to make the thing work, that component is gone. A $25 portable CD player probably contains only $5 to $7 worth of components. The rest of the price is assembly, testing, packaging, shipping, marketing, retail markup, etc. Under such conditions, a few cents extra here and there in the name of quality looks pretty expensive indeed.

Interestingly enough, the rise of home theater has probably eliminated some of this electrical-isolation problem. When a DVD player is connected to a receiver with an optical or coaxial digital cable, the mechanical disc-playback stuff is very effectively isolated from the DACs. In effect, even an inexpensive home-theater setup qualifies as a “two box” CD player.

#34

It depends on how good your hearing is. Most people WON’T notice this, probably because they had too many crayons stuck up their noses and in their ears as children. And as stated above, as people’s hearing deteriorates with age.

I used to have some good ole ‘Princo’ (samsung branded silvers) audio cd compilations which caused a high pitched “ringing” sound from the drives of nearly all cd players it was put in. After about 20s of playing, it was amplified enough that it effected the sound coming from the speakers.

Most people couldn’t hear it, unless they had their ears pressed upto the speakers, or the drive (after which they agreed they could hear it). However, it drove me freaking crazy & after about 1 minute of listening to it, it gave me a headache and made me want to hit things … punching bags/people/walls which is totally against my usual nature.

#35

I suppose if you had a crappy burner you might hear some noise that is audible from the machine but that is not what this thread started as.( Re: Audible differences between different CD-R media used for audio?).
I am thinking that most everyone that is convinced that data disks will sound inferior to the audio disks are people that have wasted lots of cash paying the extra royalties or what ever the Companies charge for for the audio disks! :iagree: :iagree: :iagree:

#36

Data and Audio CD-Rs when from same manufacturer with same top coating sound the same when used in same CD-R burner.

#37

A little OFF-TOPIC but since inferiority is being mentioned I just wanted to add that sometimes pressed CDs can sound inferior compared with CD-Rs. It is said when using the right equipment (SONY CDW-900E, CDW-900P, SONY CD-ROM drive and CD Reproducer 1.20 with special dongle key) and right media (Ricoh NY74+MA) the copy on CD-R gives better sound than the original pressed one (problem is CD Reproducer with dongle, SONY CDW-900P and NY74+MA are not available to normal users). Fact is that Ricoh has a CD-R (NY74+MA) for pro-use (72.80USD/Disc in special case or 136.43USD/5disc Spindle!!! no joke!) which is only available to people who can identify themselves as working for a recording studio or pressing facility, because the studios and many sound engineers say that the sound when played back from this CD-R is better than the pressed copy of it. These Engineers, studios and copyright issues have influenced Ricoh to not sell this media on the open market. They say that when this CD-R is available to everyone pirated CDs using this CD-R would sell better than the pressed official release (this and other reasons is also why CD Reproducer with dongle and Sony 900P is not available to normal customers)…

But I also want to state that better sound for Person A must not be better sound for person X or Y. The same is with Audio equipment. Some people like TEAC Esoteric CD-Transport and JBL speakers and others like other brands. There is no meaning in fighting over which sounds better (and I wont talk about which sounds better or not). The only thing you can say is for sure is that different systems or CD-Rs sound different. (If any of you want to know what I like just PM me and I’ll give you a description of my setup and media I use to achieve the sound I like)

#38

Um … with professional gear … wouldn’t they read any CDR better?
As Cnlson already stated … Data is Data …

The only difference with these cdr would be that they have a longer life guarantee … aka they are Archival Quality Discs.

#39

I agree but as for Archival Quality Discs, I would never spend the money on them. I have hundreds of Fugis 48x made in Japan (TYs of course) that were burned years ago that still test perfectly. And they were purchased for pennies with BB rebates. I am curious as to what the life expectancy of the TYs are compared to so called “Archival Quality Discs”.

#40

ummm more likely it is their imagination that deteriourates… they stop imagining they have the best hearing :rolleyes:

Most people couldn’t hear it, unless they had their ears pressed upto the speakers, or the drive (after which they agreed they could hear it). However, it drove me freaking crazy & after about 1 minute of listening to it, it gave me a headache and made me want to hit things … punching bags/people/walls which is totally against my usual nature.
i can totally just picture this scene… you holding someones head against the speaker with the volume at 11 until they agreeded that “Oh yes, i hear it now.” i swear i know you or your doppleganger… he must be a little ahead of you though because he got hauled off to the nut-hut a while ago…