how to tell bit resolution of redbook CDs (16, 20, 24 bit)?

Discussion in 'Music' started by Jason8, Dec 16, 2003.

  1. Jason8

    Jason8 Agent

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    Is there a way to tell the bit depth resolution of a regular audio CD? I know if it is higher than 16-bit, it will say on the packaging that it is 20-bit or 24-bit. But I have some remastered CDs that don't indicate bit resolution. If it doesn't say, then does that mean 16-bit? Perhaps is there some software utility that can say what it is? Thanks.
     
  2. Kevin C Brown

    Kevin C Brown Producer

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    CDs are always 16 bit/44.1 kHz. They might have been dithered down from 20 or 24 bit during mastering (if I'm saying that right), but 16/44.1 is all you get. You'd only know that if it was in the liner notes somewhere. Maybe someone can comment about XRCDs, HDCDs, etc, too.

    The funny thing is: if you read the measurements section of even the best DVD-A and SACD players reviewed in S&V, you *still* only get 18 to 20 bit resolution.
     
  3. ChrisPATT

    ChrisPATT Stunt Coordinator

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    Then why do some of my CDs read 24 bit on the cover?
     
  4. Brian L

    Brian L Cinematographer

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    Marketing of the fact that they were mastered using a certain process, I would wager.

    As Kevin said, a Redbook CD is 16/44.1, end of story.

    BGL
     
  5. Jason8

    Jason8 Agent

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    Thanks for the insight!

    So if all redbook cds are 16-bit/44khz, then why do the advertise some players being 24-bit/192khz? Is it just another marketing ploy, since not even high-rez audio cds can achieve that?
     
  6. Brian Perry

    Brian Perry Cinematographer

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  7. Kevin C Brown

    Kevin C Brown Producer

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    And... there are some advantages to using 24/192 DACs to decode 16/44 CDs rather than 16/44 DACs. Something to do with the steepness of the anti-aliasing filters used, among other things.
     
  8. Jason8

    Jason8 Agent

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    interesting...actually I have a DVD player that says it has 24bit/192khz DACs but it is not a DVD-Audio player, but I guess what Brian said about "anti-aliasing" filters or whatnot :b

    this is abit off-color, but when using Digital Optical or Digital Coaxial connection from DVD player to HT Receiver, can different DVD players sound better? I have heard some people comment that "oh, the audio from this DVD player has more warmth and detail" or something to that effect. But using a Digital optical/coaxial connection, you're just sending bits to your Receiver's DACs, so it's just your Receiver's DACs processing the info, correct? Or is there some "voodoo" involved?
     
  9. Brian L

    Brian L Cinematographer

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    Actually, it was my esteemed colleague Mr. Brown that commented on the filters...

    As for one player used as a transport sounding better than another, thats a subject of great debate. I personally think digital is digital in terms of moving the data from one place to another. Any sonic differences would be due to DACs, and any circuitry that is downstream of those.

    Of course, if you cruise over to Audio Asylum, you will probably find posts that say player "A" blows player "B" out of the water when used as a transport.

    These folks also think A/C wall outlets can impact the sound too.

    BGL
     
  10. Joel Fontenot

    Joel Fontenot Supporting Actor

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  11. LanceJ

    LanceJ Producer

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    From reading many posts on pro forums, most professionals very much believe in mastering in bit depths greater than 16 because it gives them an electrical "cushion" while doing whatever processing is needed. So if any computing mistakes occur, they will usually be confined to those last few bits. And when transferring to the CD standard of 44.1kHz/16bit, those mistakes will be left behind. Obviously, if you use analog processing methods then this doesn't apply (but analog can introduce it's own set of distortions so there is no free lunch here).

    As far as converting to 16 bits from say, 24 bits, all that is needed is to literally ignore those 8 extra bits--that's it. There isn't any true conversion process going on. What you are losing is the finer voltage steps that larger bit words provide, (which many recording people say is more important than the sampling rate as far as sound quality goes, at least on the high $$$ convertors they use in the studio):

    A 24 bit word gives the digital encoders/decoders 16,777,216 individual voltage steps to "choose" from to build the music waveform (a binary word has two possible values--1 or 0--in each place, so: 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 16,777,216).

    A 16 bit word only provides 65,536 individual voltage steps.

    And yes, many convertors aren't built well enough to squeeze out those extremely fine voltage steps found in the last few bits of a 24bit word. But I THINK I read somewhere that the average human can't hear better than 18bit resolution, so this may be a nearly moot point, (though the concept of processing using 24 bits is still valid).

    Now, converting from 96kHz or 48kHz down to that oddball 44.1kHz rate is where you can get into trouble--this is where high quality equipment is required for the best possible sound.

    LJ
     
  12. Joel Fontenot

    Joel Fontenot Supporting Actor

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    It's true that if you're going to be processing the sound in the digital realm, do it at a high bit-depth. I'll do that when I do my own needledrops of my LP's - I convert to 32-bit, process as I like, then re-convert back to 16 to make a CD-R of it.

    It's what the professionals do to the real masters in the digital realm that I don't like. I'd rather that they didn't digitally process at all. I know that analog processing adds it's own distortion, but it's a much more "agreeable" distortion that is much easier on the ears when done right.

    Joel
     
  13. Scott Strang

    Scott Strang Screenwriter

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    [quote}..do it at a high bit-depth. I'll do that when I do my own needledrops of my LP's. [/quote]

    Howdy Joel

    Are you using a soundcard with digital in and an outboard a/d? If so what a/d are you using? I've been wanting to transfer some reels and LP's to some hi-res format for storage probably in WAV format. I'd like to do them at at least 96khz/24bit.
     
  14. Ken_McAlinden

    Ken_McAlinden Producer
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  15. Joel Fontenot

    Joel Fontenot Supporting Actor

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