Burning 24-bit audio to CD

[Xoanon]

Using Nero as an example, if I drag and drop a 24-bit audio file into a CD and burn it, will it cause issues when I play it back?

I was under the impression that files must be dithered down to 16-bit depth before burning to CD but I wondered if I just burned a file as-is if it would be OK?

[MOVIEGEEK]

I doubt Nero will accept a 24bit audio file and if it did it would convert it to 16bit, even if you were able to make a 24bit audio CD your standalone players wouldn't support it. If you made a data CD then some software players would support it(assuming you have a 24bit soundcard).

[Xoanon]

Well I can drag it into the burning window and it shows up OK. I just wondered if I could burn it (Ive not got that far yet).

[hech54]

Audio CD spec is 16Bit...plain and simple.

[Xoanon]

I know that, but you do see CDs saying "20 bit" on them, so I guess I am saying I wondered if Nero does the dithering itself if you burn from a 24 bit source?

[yoda313]

I think that refers to the recording method not the playback method.

I have the Joe Satriani concert dvd from a few years ago that says it was recorded in "high definition" but it is a dvd so that statement really doesn't mean anything. THat just means what source it was derived from.

[jman98]

I know that, but you do see CDs saying "20 bit" on them, so I guess I am saying I wondered if Nero does the dithering itself if you burn from a 24 bit source?

Yes, Nero will absolutely convert your audio to 16 bits so that it conforms to audio CD standards.

"20 bit" can mean one of 2 things.
1) The work was done in 20 bits until it came time to master and then it was converted to 16 bits.
2) You have an HDCD which through proprietary and patented processes has a way to pack 20 bit info into a 16 bit field that is fully compatible with current CD technology yet allows HDCD player the ability to extract a little extra info out of it. Wikipedia has an article on it if you want more details.

[Xoanon]

OK but surely Nero's in-built 24-to-16bit technology is no subsitute for dithering to 16-bit in something like Audition and then burning? I forget what the Audition help file says but if you dont dither to 16-bit then it introduces artefacts into the audio?

[MOVIEGEEK]

For resampling WAV I like to use CDWave, I'm sure Audition will do a better job than Nero.
Have you thought of making a DVD-Audio disc?

[Xoanon]

No I use Audition for all my mastering and I always mix at 24 bit then dither down to 16. I just wondered if I didnt do this step, how would the resulting audio sound?

[SingSing]

Have you found any speakers that can play back at 16 or 24 bit resolution ?

[Xoanon]

Yes I have some, I just wondered about the theory before being able to drag a 24-bit file into Nero and burning the track as is, if it would cause any issues.

[Cornucopia]

Any app that accepts 24bit audio (as you say that Nero says it does) and is going to a standard AudioCD (not DataCD, not HDCD) MUST be outputting 16bit.
So basically you're left with 3 ways to do it:

1. Truncate (BAD, BAD, BAD!!!!)
2. Round & Truncate (Common and accepted, but still not great)
3. Dithered, Round & Truncate (High quality)

You could further add Noise-shaping in there...

The best hardware and the best audio apps (incl. Audition, ProTools, Oxford) do #3 (or "4"). Nero probably does #2. I sure hope it doesn't do #1.

If you HAVE Audition, there's no reason NOT to use it as your main downrezzing app instead of Nero.

Scott

[greymalkin]

Have you found any speakers that can play back at 16 or 24 bit resolution ?

huh? speakers have nothing to do with this.

[Xoanon]

1. Truncate (BAD, BAD, BAD!!!!)
2. Round & Truncate (Common and accepted, but still not great)
3. Dithered, Round & Truncate (High quality)

Thanks for a reply Scott, these are terms I was looking out for. Can you explain what each one is and why they are bad/important where applicable?

[Cornucopia]

All of the processes must finally truncate. This is where you lop off the bottom 8 bits from a 24bit signal, leaving only the top 16bits.

Rounding is just what it sounds like. Just like you can round any number to a certain degree of accuracy (Whole Integer, 10ths, 100ths, 1000ths, etc), you also round the signal (each sample) to the nearest 16th bit accuracy.

Dithering applies pseudo-random noise to the signal prior to rounding to make the rounding be Unpredictable (if it's predictable, it's actually more like distortion and sounds like distortion--random/white/pink noise at that small level is MUCH less objectionable).
Dithering also has the added bonus of retaining some of the perceived 24bit resolution...

The analogy used most often is this:
Try to look at a house through a picket fence. You know the house is a whole image, but the picket fence cuts it up so you can't see but sections of it. (That's like 16bit)
Now move you body so that the pickets move back and forth past your eyes and a fairly fast rate.
Yes, you get a certain blur from the pickets in the foreground, but now it's like you can see the whole house!

I said pseudo-random, because one really neat thing about digital is that you don't really have completely random signal. Because of this, you can "remember" this signal and partly subtract it from the resulting truncated signal which allows you to keep much of the resolution benefits of the 24bit original, yet be 16bit and not have added noise.

Noise shaping is an extension of this. Since this random signal isn't really random, you can manipulate the numbers so that the "rounded" output is statistically stronger in the frequencies that are less sensitive to the ear (very high and very low) and statistically weaker in the more sensitive middle sections. So this "added noise" is even quieter.

What this all means is that if you just use #1, you'll get much more gritty distortion, particularly in the quiet sections. #2 might sound better and be OK for many casual listeners, but it also doesn't have the clarity and transparency that was in the original. #3 pretty much does. It sounds "natural". and #4 also does, but with less noticeable background noise.

Scott

[Xoanon]

Many thanks indeed!

So burning a 24 bit with Nero, one would assume it just does #1?

[SingSing]

Have you found any speakers that can play back at 16 or 24 bit resolution ?

huh? speakers have nothing to do with this.

It does matter. there are two new formats after audio CD: the audio DVD and the SACD, and both can go beyond 16 bits. See their wiki.

They both soundly rejected by cosumers, because you can't hear the different.

[MOVIEGEEK]

Have you found any speakers that can play back at 16 or 24 bit resolution ?

huh? speakers have nothing to do with this.

SingSing,
I also thought you were kidding(ie digital speakers) but there's no difference because speakers are analog.
The only thing that matters is frequency, as long as the speakers can reproduce 20-20,000Hz you are good.
BTW: DVD-Audio and SACD are superior to CD but that's another topic.

Now back to Nero's dithering capabilities.....

[olyteddy]

Many thanks indeed!

So burning a 24 bit with Nero, one would assume it just does #1?

Why not just try it? What's a blank CD cost? $.25 US or so...

[edDV]

Many thanks indeed!

So burning a 24 bit with Nero, one would assume it just does #1?

Have you thought to ask Nero?

You will need a very high end audio system (or very high end earphones) to judge the difference.

[netmask56]

Many thanks indeed!

So burning a 24 bit with Nero, one would assume it just does #1?

Why not just try it? What's a blank CD cost? $.25 US or so...

Yeah! I agree CD's cost around $0.15 AU so put us all out of our misery and burn a b%$@&y disc and report back...!

[greymalkin]

Have you found any speakers that can play back at 16 or 24 bit resolution ?

huh? speakers have nothing to do with this.

It does matter. there are two new formats after audio CD: the audio DVD and the SACD, and both can go beyond 16 bits. See their wiki.

They both soundly rejected by cosumers, because you can't hear the different.

MOVIEGEEK answered the speaker thing, but I just wanted to say I have a lower end SACD/DVD-AUDIO Player and my surround sound system is also not very high end and I can tell a major difference between them and regular CD. anyone who can't hear the difference has hearing damage. Even the stereo SACD's I have are noticably better.

[edDV]

Have you found any speakers that can play back at 16 or 24 bit resolution ?

huh? speakers have nothing to do with this.

It does matter. there are two new formats after audio CD: the audio DVD and the SACD, and both can go beyond 16 bits. See their wiki.

They both soundly rejected by cosumers, because you can't hear the different.

MOVIEGEEK answered the speaker thing, but I just wanted to say I have a lower end SACD/DVD-AUDIO Player and my surround sound system is also not very high end and I can tell a major difference between them and regular CD. anyone who can't hear the difference has hearing damage. Even the stereo SACD's I have are noticably better.

Yes if you say so but those are pro remastered recordings. GavSalkeld is bit reducing his Adobe Audition generated audio from 24 to 16 bit. Granted he said nothing about the source quality. Nor did he mention using 96Kb/s sample rate.

[Alex_ander]

Why not to author it as mini-DVD and burn to CDR (Nero has that option)? With 24bit/48kHz the bitrate is not dramatically higher than with standard CDs. The mechanical speed needs 1.75 factor, but those SVCD capable DVD players provide double speed. So it even looks possible to make a CDR-based mini-DVD 'audio+stills' (DVDLab 2.xx), working in most players.

P.S. Corrected: SVCDs, not SACDs of course.

[Xoanon]

So it even looks possible to make a CDR-based mini-DVD 'audio+stills' (DVDLab 2.xx), working in most players.

I didnt know that was possible

[edDV]

24bit/48kHz uncompressed PCM would require 50% more bit rate. Are you suggesting Mpg or AC-3 compression?

[Alex_ander]

No, I suggest to keep LPCM. The only problem with reading at as high bitrate (1.64 times higher) is faster rotation. SVCDs need double rotation speed for reading at higher bitrates, but this is solved in most DVD players.