Comparing rips


I did an experiment and the results are mystifying to me. I ripped the same track with three different programs:

iTunes (error correction on)
dbpoweramp (free version) - AccurateRip verified
Exact Audio Copy - AccurateRip verified

I ripped them all to WAV.

iTunes and EAC returned the same number of bits (there are all "size on disk" numbers):
191,135,744

dbpoweramp returned a slightly larger file:
191,172,608

I then converted them to Apple Lossless files using the encoder in iTunes.

Again, two of the files matched the number of bits, but this time it was EAC and dbpoweramp!:
85,237,760

iTunes returned a different number:
71,892,990

I then ripped the track directly to Apple Lossless from dbpoweramp and dbpoweramp (EAC doesn't do this) and the results were as before:
iTunes: 71,892,990
dbpoweramp: 85,237,760

What is up with this? Has anyone seen these kind of results also?

Thanks for your help.
Mark
markhyams
One thing to check out is the issue of drive offset numbers. If I remember correctly, iTunes gives you no control over the drive offset and EAC and dBpoweramp both do. When I played with this a while ago, once I got EAC and iTunes to use the same drive offset, then the WAV files compared exactly. If I remember correctly, I had to set it to 0 in EAC to get EAC and iTUnes to produce exactly the same files. Not sure if I compared dBpoweramp at that time. But it something to consider.
could it be the track information? The reason I use dbpoweramp is because it works at attaching the library track information for wav... others I have used had problems.
Dtc is correct, it is probably offset. iTunes does not get it right. In resolving systems you can hear the difference too. Offset is the number of nulls before the music data starts.

I recommend using dbpoweramp always with Accurate-Rip enabled. Gets the data file correct and the offset correct.

Steve N.
Empirical Audio