Lord Hasenpfeffer wrote:

I still have to wonder about the "threshold of human hearing" they speak
about, because with playback systems that have a volume knob, it just doesn't
apply.

Unless I am mistaken, frequencies discarded during encoding remain
absent during playback regardless of volume.

Yep. That's why setting an absolute threshold (relative to FS) is strange to me. It
assumes that everybody is listening at the same level, which, with a volume knob,
isn't necessarily the case.

This would mean that indeed if you raise the level of a song, more stuff gets
encoded.

However, Bob has quite a point where he says that encoding more frequencies leaves
less bandwith for encoding the stronger frequencies correctly. This applies
especially to fixed bit rate encoding. Even more so, raising the absolute level of
the *noise* (what you're doing when raising the level of a whole song) will make
the encoder work harder to encode that noise more precisely, thus taking bandwith
away from encoding the real stuff. The whole idea of the lossy compression is to
leave out what you won't hear. Trying to get those frequencies back in goes against
the whole idea of compression, and will hurt the non-left-out frequencies.
Especially when it would be extra noise you're encoding.

The amount of noise, and the way it influences encoding, differs per song and
therefore results will vary between songs. So alas I think when you want to achieve
optimum results it is still a matter of listening, and not setting standard batch
levels for all songs.

Your own preferences OTOH are of course an entirely different matter. If I
understood it correctly, your wish of "normalizing" songs is also fed by the fact
that you want to standardize your listening experience. Nothing wrong with that,
it's just your own preference. Maybe it would be more wise to find out what crest
factor you really like and stick to that (and hope you won't change your preference
after the stuff is encoded), with the listening experience itself in mind and not
the encoding.

FWIW, I'm currently in the process of transferring my own CD collection to MP3 for
playback on the DVD player. The number of CD's I have just takes too much space in
the living room. So I will put the stuff on MP3 CD's for background music and keep
the CD's in the attic for archiving, and get a CD from there when I actually really
have the time to sit down and listen to the music (which will be only a few times a
year I guess).

I rust rip and encode, for two reasons: 1) it doesn't tamper with the music as-is,
2) it takes less time to do. For the encoding I use the lame windows encoder (pun
intended) with the setting VBR, highest quality, 64-320 kb/s. With the 50 CD's I've
already done so far, I didn't notice any very obvious artefacts yet (and I know
what to listen for.. swishy cymbals, strange bass to name a few). That's why I'm
interested in the tracks Peter mentioned, tracks that give encoders a hard time.
Having these disks myself makes it easy to try the test.

If you want to order a set as well to do the same tests with your encoder, you can
find the ordering info at http://www.recaudiopro.net
Ordering one is worth the enjoyment of the tracks, as well as the learning
experience by reading the liner notes: "how did they do that??". Highly
recommended.

Good luck,

Erwin Timmerman.