The world of DAE has only recently captured my interest so I admittedly have a limited knowledge of the subject; however, I have been doing a lot of experimenting over the last couple of weeks by extracting audio from my CDs to HD for archival purposes. Since I want to be sure I'm not compromising my results, for each CD, I've been extracting the audio from each CD several times, and with a wide variety of the popular software programs out there. In addition, I've been using multiple source drives. For each unique combination of CD/Drive/Software/Extraction Speed, I've recordered the results by calculating the CRC32 of the sound from the WAV file. I found a program which seems to do this quite nicely, and for free from the following URL: http://www.kagi.com/cyberdyne/

For obvious reasons a regular CRC32 *file* checking utility will often report different results even with identical audio.

The drives I've been using are a LiteOn-LTD63D (GHR7 firmware), and the Plextor 48/24/48A (ATAPI).

Thus far, it hasn't seemed to make a difference which software package, drive, ripping or recording speed I've used. E.g. even ripping/burning on the fly at 40x and then extracting the wav files off the *copy* has yielded "bit-for-bit" perfect copies of the WAV files. There has been the odd track that does not compare 100% equally, (perhaps there is a fraction of a microsecond difference), but that is the exception to the rule, and doesn't seem to follow any pattern.

I was shocked to find out that my $40 piece of crap LITE-ON LTD63D is actually highly regarded (so it seems) in the various forums for its DAE ability.

Anyway, would be interested to hear anyone's comments/feedback on my experience thus far...

-Dave

The software is very important if you read / copy damaged discs (such as heavily scratched discs or Cactus 200 discs). But, of course, without hardware which can handle such thing, the software won't help either...

You mean the offsets. The data will be displaced depending on drive.
That's right. That's the common behaviour with modern drives. Perfect DAE if the CD is in good condition.

But you won't get identical copies if the CD is scratched or its quality is poor.
EAC reads twice and compares, so it will inform if there are errors.
Plextools relies on C2 errors to repeating reading only when it's necessary, so it's faster and as reliable (the best with the Plextor)
Feurio will report C2 errors, so the extraction is perfect if there is none.
To compare WAVs I use "Compare WAVs" tool in EAC.

Yes, the EAC tool "compare wavs" can detect offsets, and skippings in the audio, a regular CRC checking can't.

There is also AccurateRip which compares (after offset correction) the CRC of your file with the one got by all previous users that ripped the same CD.

For documentation about offsets : http://www.ping.be/satcp/tutorials.htm