There's a couple things you're hinting at that can be explained with math
and one that can be explained psychologically:
Signals with compact support in the time domain have infinitely long
support in the frequency domain. When you color a sound with non-flat
frequency response, you lose the compactness of the original signal.
Muddiness comes about when the frequencies have different group delays or
when some frequencies are cut.
The best mix preserves the distinctness of each part. One of my favorite
articles is "Tone and Voice" by David Huron. The article makes it clear
that musical practice derives itself from balance and independence of its
parts (specifically as applied to voice leading but when applied more
generally it has some insights for engineering more modern music)
Chuck
On Apr 5, 2013 9:32 PM, "Ralf Mardorf" <ralf.mardorf(a)alice-dsl.net>
wrote:
I try to find better words in English now.
I care less about the bandwidth of the frequency. If the bandwith
becomes smaller or does colour some frequencies, it's ok for my taste,
assumed it is not too much. If the range endet at 18KHz for the original
and a copy or transformed by a codec has loss, by ending at 15KHz, I'm
able to notice this, but won't name it "I hear loss of highs", as long
as the transparency and loudness dynamic, IOW the atmosphere of the
recording is the same.
It's important that the loudness ratio between the instruments is kept,
the room is kept.
Good recordings made with a 4-Track cassette recorder do sound less good
than a recording with professional gear, if you take care about those
things, when listening on professional gear, but it's impossible to hear
it on an averaged consumer hifi.
Taking care about the bandwith of the frequencies is not completely
unimportant, but even something important as signal separation, is not
very important, as long as you take care about this limitations, when
doing the mastering.
The music will sound completely different biased on different consumer
hifi gear, it doesn't matter if it was recorded in a professional or in
a home studio.
A good audio engineer takes care that the sound is most transparent,
even if the frequencies are cut etc..
Sure, if you play a good recording on a very bad hifi, it does sound
ugly, but very often it does sound better, than at least the old MP3s I
know, because the ratio between the instruments etc. seems to be more
biased by MP3s than by bad gear.
Optimal is 48 KHz, but I also mentioned that for some recordings even
32 KHz is ok. For me it's bad when "transparent" sound becomes
"muddy".
"Muddy" doesn't mean less highs only (it often comes with less highs),
"muddy" is for a loss of transparency. The original sound might separate
guitar and trompete very good, even when they are in the same position
of the room, but they have accentuations by different frequency bands.
If a codec does remove frequencies, those instruments will be less good
separated. This is the kind of loss I can't tolerate. The loss of highs
and a little bit noise are less important for me.
Many people nowadays aren't aware how to make sound transparent even
with cheap analog home recording gear, but it's possible. We even don't
need a compressor, many things a compressor does, can be done by EQs.
Quality doesn't mean 2 Hz to 22 KHz and 200 dB S/N ratio. When using an
analog tape 40 Hz to 14 KHz and 67 dB S/N ratio (EIAJ) and I take care
about frequency issues and less good channel separation by the mix, I
can do an amazing transparent mixes.
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