Remove pre-emphasis from cd's

Hey, I have a couple of cd’s that have the pre-emphasis on them. The high frequencies are boosted. When I play them through my upsampling d/a converter at home, the highs are not reduced. So I want to remove the pre-emphais and make the copies like regular cd’s. I am wondering if there is any software that can remove the pre-emphasis? Or is there a filter or plugin that I can use? I do have Sound Forge 7. Any help is appreciated.

Brian :slight_smile:

Hi Brian.

Can you explain how you know that emphasis is turned on please? To my knowledge, this is only determined by the Q channel of the subcode that is on the original CD. If it is in the audio itself, then I don’t know of anyway to get rid of it, but I’m sure there might be something out there. If it is in the subcode only, then a simple rip should get rid of it I would think.

Richman, I do have an old cd player that displays if a cd has the pre-emphasis. The pre-emphasis flag on the disc turns on a high frequency filter on the cd player to reduce the high frequency content on such a disc. There aren’t many discs that have this luckily. The purpose is to reduce high frequency noise on playback, but dac’s have gotten really good that I don’t think anybody makes these discs anymore.

Brian

I can only assume that if you rip these CDs that the emphasis bit will be removed since it only exists in subcode. I am pretty sure of this but I can only confirm it at work tomorrow. Have you tried ripping and reburning yet? If so, what was the result and what did you use to rip?

All of the software that I rip the cd to the harddrive does not do a de-emphasis. The highfrequencies are still louder than they should be. I’ve used Nero, Sound Forge, EAC, Fureio. Know of any software that might work?

Brian

I wasn’t yet able to look through the RED book to determine if this is just in subcode or if it is actually part of the audio. From what you say, it sounds like it is in the audio too. If this is the case, I really don’t know what to suggest. Several people where I work use GoldWave to edit audio. You might give it a look.

I don’t realize any software that does that (in fact, I don’t know how to detect if a disc has pre-emphasis), but cuesheets have command for that option…

http://www.dcsoft.com/cue_mastering_progs.htm

The problem is probably to find a program that interpret that command in the cuesheet.
I would try the original: CDRWin.
If it doesn’t work, then Feurio and EAC.

I just want to let everyone know that I did find out that Waves Q10 does have a preset to remove the CD pre-emphasis from a wave. You can check them out here http://www.waves.com/htmls/prods/indi/q10.html#
Thanks for everyones help,
Brian :slight_smile:

30th June 2009

I apologise that this reply does not directly answer your question,
but I just wanted to say that

The BEST ‘no compromise’ ‘high end’ method to solve your problem
is to build an
’old fashioned’ analogue filter
that should only cost about GBP £1 to GBP £10 (USD $15)
( ignoring the cost of a power supply / mains adapter of the correct voltage )


Boost / Pre emphasis the high frequency to REDUCE NOISE
has been done for more than 50 years on ‘old fashioned’ vinyl records.
The designers of CD have used this ‘time proven’ method for some CD.

For most recording,
the BEST method of producing a CD is to boost / pre emphasis the high frequency
followed by
The CD player or DAC (digital to Analogue Converter) will produce music that has too much high frequency
followed by
The CD Player or DAC will check if the CD has been ‘pre emphasis’.
If the CD has been 'pre emphasis’
the CD player will put the signal through an ‘old fashion’ analogue filter
(which is just a few cheap capacitors , a few cheap resistors)
(and a cheap 20 pence or 30 cents ‘op amp’ or transistor or valve / tube)
which will remove the CORRECT amount of high frequency.

The BEST method is so complicated, and will produce the following advantages …

  1. Reduce distortion for very quiet high frequency

All DAC (Digital to Analogue Converter) IC (Integrated Circuits) costing from GBP £3 (used in most CD players and DAC
selling for GBP £110 to GBP £2000)
to GBP £50 for a set of 3 IC for CD players that usually sell in ‘High Street’ shops for GBP £5,000 to GBP £20,000)
are
very good for producing very LOUD LOW frequency sound, with barely any distortion)
(but CD player produce a lot of of distortion for very QUIET HIGH frequency sound.)

If you boost / pre emphasis the music for high frequency,
the quiet high frequency sound will be louder,
so
the problem with reproducing very quiet high frequency is reduced
so the distortion is reduced

  1. Any high frequency noise,
    any ultrasonic noise (that might irritate the amplifier)
    produce by the GBP £3 DAC IC
    and the GBP £0.30 (that is correct 30 pence !) op amp IC
    (that converts the electric current from the DAC IC)
    (into electrical voltage for the amplifer)
    is also reduced by the cheap ‘old fashioned’ ‘analogue’ filter

( Please look at 10000 Hertz square wave performance )
( into difficult loads with 8 ohm resistor + 0.1 uF to 2 uF capacitors )
( of some ‘high end’ amplifiers selling for thousand of pounds,
( and you will see that )
( ultrasonic noise can create ‘over shoot’ and ringing ! )


If you are into serious ‘High End’ equipment,
and spend an insane amount of money on HIgh FIdelity equipment,
I THINK that you should be able to hear the difference,
but I need the same recordings on CD with and without pre emphasis

  • ‘old fashioned’ analogue filter to reduce the CORRECT amount of high frequencies
    to prove
    if my ears can (or cannot) hear the difference

affordablevalvecompany CDemp001.htm