WBRW wrote:
I would be somewhat surprised to learn that any mainstream commercial
release has ever gone out without being normalised (using the strict
definition of the term) to somewhere within 1db of FS.

How about this:

Snip list of tracks

Well, 89.1% (depending on if that is power or voltage) is about 1 percent
or so below FS.

"The Sign" was Ace Of Base's biggest U.S. hit ever, reaching #1 on the
Billboard chart in 1994 -- yet, on the album, it actually has the
LOWEST peak level of all the tracks, only hitting 56.2% of full scale,
or -5.0 dB!

Sounds like they normalled the whole album to retain relative levels
across the tracks. This is a perfectly reasonable thing to do.

And with regard to MP3 compression, an MP3 file can be LOSSLESSLY
NORMALIZED on a frame-by-frame basis in 1.5 dB increments. The actual
compressed data is NOT changed -- only an ancillary "loudness
scale-factor". You can even LOSSLESSLY add fade-ins and fade-outs to
MP3 files, by changing the scale-factor on a frame-by-frame basis.

Indeed, I had forgotten what the resolution was, but was aware of this
functionality, not that it makes any difference if the hypothesis that
spawned this discussion holds, the damage is done by then. However the
very presence of this gain factor in each frame hints that any competent
codec should not be sensitive to input level except in so far as it
modifies this value (Otherwise you have more less entropy in the output
file then you could have, and that is bad in a compressed stream).

In fact, you should be doing this anyway with any MP3 files you might
download, as today's over-compressed pop music often drives MP3
decoders into extreme amounts of clipping unless the level of the MP3
file is reduced to a "safe" value. (The MP3 ENCODING is fine -- it's
just the DECODER that adds its own extra clipping upon playback.)
I've seen downloaded MP3s where the file had to be knocked down by 6
dB, just to get it below the level of clipping during playback!

Ouch, but I suppose some overshoot in the reconstructed audio is
going to be present....

Regards, Dan.
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