But (you knew that was coming, yes?) parts of your explanations really do not make sense, so I suspect that there is probably something else (other than bit-perfect copies producing different sounds through the same equipment) going on.
Here are some possibilities:
- Red Book CDs have no sector headers and much less error-correction information than data CDs. Reading them often produces soft errors, i.e., a second read might return different bits.
- mismatches between media formulations and drives means that burning a CD-R often creates a significant number of marginal bits, guaranteeing some soft errors; only some of these can be corrected by the drive firmware. Playing the disc allows even hard errors to be concealed; ripping is NOT playing.
- most of the sonic differences in both recording and playback occur in the analog circuitry, in the conversion to or from digits, or when converting electrical signals to mechanical motion. No two playback chains will sound exactly alike.
- any process that modifies the actual bits will change the sound; the purpose of your restoration work is to change the sound, and your tools are complex.
By comparison, FLAC is very simple: remove redundancy and create a table that lets you reconstruct the original. Not "approximate", reconstruct. It's zip for waveforms instead of text.
Here's an experiment: take any document you have, and zip/unzip it fifty times. If no errors are reported, the zip files were not corrupted, and the final output will be the same as the first input.
FLAC does the same thing for digitized sound files. Your playback chain should be time-independent: if you put the same bits in tomorrow that you put in today, you will get the same sound out tomorrow that you got today. If a FLAC file gives you the same WAV back again tomorrow that you put in today, and you use the same playback chain in the same functional condition, it will sound the same.
Whatever is happening to give you different sound is not the FLAC step.
Cheers -- m.
After this I will look at FLAC differently. I am still not clear why commercially made CDs aren’t currently made available in FLAC instead of WAV. I suppose it's that FLAC is not decodable in some players. As mentioned, multiple CD soundtrack sets are the default method when the running time of music goes over 80 minutes.
About CDRs, perhaps it's because of less-stringent Redbook standards that different CDR-brand discs - copied identically - sound different from each other. At one time I relied on favorite brands because of the detectable equalization-differences. Now I avoid this by copying directly onto drives.
My professional background was in pre-digital film restoration, but I have seen many changes in the time with many brand-name "upgrades" in technology that ended up being huge set-backs. Some were just wonderful - but many times "the way to go", sometimes just wasn't. The concern is that there is a huge amount of work involved for anyone transferring these discs. In order to feel "safe" one should of course back everything up in multiple copies. In dealing with FLAC, this just one adds one more issue. In order to be truly archival, it must also be truly retrievable. But the difference and expense in this kind of storage is so small - my question is, "Do I need to go that step, to make it even smaller?"
It's probably no big deal; it's just me. Someday everything will be much more miniaturized anyway. CDs will be copied with devices that will scan discs from pointers at long distances.
In the meantime, thanks, Mark. I really appreciate your wisdom and knowledge-base.
Now if someone would just invent a method of removing wow and flutter from music that doesn't read it as "vibratto"..