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Topic: Judging quality of burns by comparing WAV's? (Read 2847 times) previous topic - next topic
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Judging quality of burns by comparing WAV's?

I've been looking for a way to count c1 errors with my drives (Asus E616 & Teac W524E) for a while now but it seems there isn't a way, so I've been trying to figure out a way to judge the quality of my burned CD's. An idea I have is this:

- Rip an Audio CD to wav
- Write that WAV to a CDR
- Extract WAV from CDR
- Compare original & new WAV to see percentage difference.

Obviously there are a few flaws in this, e.g media quality and drive reading quality but assuming I use Mitsui or Taiyo Yuden it should give some indication shouldn't it?

Thing is, how can I get a figure of difference between the 2 files, either a percentage or the number of different samples or something like that?

Cheers,
-dave

Judging quality of burns by comparing WAV's?

Reply #1 –
EAC will allow you to compare wavs with the "compare wavs" command of the "tools" menu. However, you should never find any difference exept offset.
C1 errors are corrected by the drive, as well as C2 errors. Red book states that the C1 error rate must be below 220 per second averaged on 10 seconds, and that there should never be any uncorrectable C2 error, that is, exept offsets, that your wav files should always be exactly the same.

In practice, any CDR from good to bad can give you identical wavs. A CDR returning you some errors in a wave is very close to be a coaster.

See, you've got C1 errors (no effect on the wav). Then, C1 uncorrectable errors become C2 errors (no effect on the wav), then C2 uncorrectable errors become differences in your wavs (quite inaudible), then, differences that couldn't be concealed become audible clicks.

To measure C1 errors, you need CD Doctor, but it should only work with Sanyo and LiteOn drives.

Judging quality of burns by comparing WAV's?

Reply #2 –
Quote
EAC will allow you to compare wavs with the "compare wavs" command of the "tools" menu. However, you should never find any difference exept offset.
C1 errors are corrected by the drive, as well as C2 errors. Red book states that the C1 error rate must be below 220 per second averaged on 10 seconds, and that there should never be any uncorrectable C2 error, that is, exept offsets, that your wav files should always be exactly the same.

In practice, any CDR from good to bad can give you identical wavs. A CDR returning you some errors in a wave is very close to be a coaster.

See, you've got C1 errors (no effect on the wav). Then, C1 uncorrectable errors become C2 errors (no effect on the wav), then C2 uncorrectable errors become differences in your wavs (quite inaudible), then, differences that couldn't be concealed become audible clicks.

To measure C1 errors, you need CD Doctor, but it should only work with Sanyo and LiteOn drives.

So why all the fuss about c1 errors?

Are you trying to tell me that as long as my c1 errors per second is below 220 and I have no C2 errors then every CDR will sound exactly the same and give me the same CRC every time I rip, even if I use a different drive?

Now I'm doubting the usefulness of EAC.

I've had even brand new pressed CD's show a few errors (resulting in 99.8% quality for example) with EAC. What causes this? Surely there aren't C2 errors or an excessive amount of C1 errors? These are CD's that are totally clean BTW.

Hmm, now I'm confused.

-dave

Judging quality of burns by comparing WAV's?

Reply #3 –
dgover2:

On pressed copy-protected CDs (such as Cactus Data Shield and other shit...) you can count in common up to 10000 (ten thousand) or even more intentional C2 errors... Recently I got into hands one copy-protected Audio CD (Czech provenience) where on 13 tracks were more than FORTY THOUSAND C2 errors, but Feurio! just sent the message O.K., there were xxx C2 errors  I heard the original CD (and the burnt out CD-R) at least ten times very carefully on vintage equipment and there is nothing disturbing or audible...  (w00t)

Judging quality of burns by comparing WAV's?

Reply #4 –
Quote
Are you trying to tell me that as long as my c1 errors per second is below 220 and I have no C2 errors then every CDR will sound exactly the same and give me the same CRC every time I rip, even if I use a different drive?


Sure, no C2 errors means perfect Wav.

Quote
I've had even brand new pressed CD's show a few errors (resulting in 99.8% quality for example) with EAC. What causes this? Surely there aren't C2 errors or an excessive amount of C1 errors? These are CD's that are totally clean BTW.


Any wav error comes from a C2 error (otherwise your computer hard drive or RAM are dying). Any C2 error comes from a C1 error.
Errors are not a property of the CD, but of the playback. The same CDR can be read without error in a given drive, and not be recognized at all in another.
CD ROM drive read audio CD at the maximum speed they can, that is the speed a whitch the error rate is the highest, but doesn't cross the "uncorrectable C2" boundary. But sometimes, a C2 error can occur akll the same.
The red book definition of no C2 error applies on 1x playback on calibrated drives, certainly not on 32x ripping.

Quote
So why all the fuss about c1 errors?


They are a good way to compare burning quality on CDRs, that are an unreliable format. Mostly a matter of speed. Burners won't always succeed to burn CDRs at 48x without errors. It's also a matter of CDR media / writer association. More generally, they show you if the CD reading is perfect, correct, average, bad, etc.

Quote
Now I'm doubting the usefulness of EAC.


EAC has not been proven very useful as long as you rip only brand new pressed CDRs on a well working drive. But this ideal case is seldom seen in real life. As soon as you rip used CDs, or any CDRs, or use an average drive, EAC becomes very useful. Not to mention that you can always scratch a CD by accident, without noticing it.
 

Judging quality of burns by comparing WAV's?

Reply #5 –
Thanks Pio2001, that cleared some things up.