Aja, ExactAudioCopy and mastering differences...confusion!
Posted: Tue May 09, 2006 2:10 pm
I started the same thread at sh.tv, but I could use your experience as well.
I tried to compare the song "Peg" from my German unremastered Aja CD against a file sent by forum member DrJ from his US unremastered CD. I was always convinced that they were completely identical, save for some different leading lengths. However, there was this minimal EAC peak level difference: 88.7 versus 88.9.
Previously, I had just tested samples of 30 seconds of length or 1 minute. Once I had trimmed the leading lengths, inverted one file and pasted it over the other, I had always gotten an optical zero line, which means that they cancelled out completely. Or so I thought.
This time, DrJ sent me the complete song Peg. As usual, after trimming the beginnings, inverting one file and pasting, the resulting file looked as if it were totally silent. However, that was not the case. The peak level of that resulting "difference" file is 0.7%, and the music is still audible, however at a very low level.
If these two were from different masterings, they should not stay in synch, nor should the resulting "difference" file be of souch low volume.
If these two were from the same mastering, they should cancel out completely, not approximately.
I did the same attempt after normalizing the two files, and the result was similar: A "difference" file with very low volume music, peaking at 0.7%.
By the way, here is the "difference file":
http://download.yousendit.com/FA11DE187F0F6856
I tried to compare the song "Peg" from my German unremastered Aja CD against a file sent by forum member DrJ from his US unremastered CD. I was always convinced that they were completely identical, save for some different leading lengths. However, there was this minimal EAC peak level difference: 88.7 versus 88.9.
Previously, I had just tested samples of 30 seconds of length or 1 minute. Once I had trimmed the leading lengths, inverted one file and pasted it over the other, I had always gotten an optical zero line, which means that they cancelled out completely. Or so I thought.
This time, DrJ sent me the complete song Peg. As usual, after trimming the beginnings, inverting one file and pasting, the resulting file looked as if it were totally silent. However, that was not the case. The peak level of that resulting "difference" file is 0.7%, and the music is still audible, however at a very low level.
If these two were from different masterings, they should not stay in synch, nor should the resulting "difference" file be of souch low volume.
If these two were from the same mastering, they should cancel out completely, not approximately.
I did the same attempt after normalizing the two files, and the result was similar: A "difference" file with very low volume music, peaking at 0.7%.
By the way, here is the "difference file":
http://download.yousendit.com/FA11DE187F0F6856