[linux-audio-user] Fwd: [Jamin] Re: soft clip: Achieving Gain, inconsequential overloads

[Malcolm Baldridge]

I've followed this thread with some amateur interest, as I am not and have
never even pretended to be an audio professional.  I will say this
however... I think there are a couple of levels of discrimination involved
with this "louder is better" thing, which is a bit similar to the similiarly
greatly annoying trend of television manufacturers' rising colour temperatures.

There's the immediate impression... "OOOH!  Louder!  I can "hear everything"
better" or whatever it really is.  And then there's the "Wait a moment,
where are the dynamics?  A piccolo doesn't really sound like it has a 200HP
air compressor hose attached to it."  Let's not even venture into the
shark-filled waters of how you're reducing effective detail by "raising the
floor" to such a degree, or the clearly obvious clipping and distortion
you're causing.

Incidentally, the "additional harmonics" argument is a little weak given the
fact that the digital audio chain is not perfect, not by a longshot.  For
one thing, anything above 22KHz is aliasing noise and should be filtered out
by your decoding sections.  For another, you have ZERO TOLERANCE for power
levels beyond +/- 32767.  Zero.  That nearly 90 degree shape in the
truncated waveforms means you've overlayed ~ 22Khz crap onto your 100-8Khz
sound.  That's NOISE, and what's worse it's at nearly maximum signal level too.

Even as an amateur audio consumer, I find FM radio annoyingly companded. 
It's like listened to a used car commercial.  To get that kind of audio out
of a CD would be completely unacceptable.  Alas, I am not a fan of rock
music so perhaps I'm just out of touch with its sonic priorities.

I have a friend who is a recording pro (who invariably sniggers and laughs
at my commentary on audio matters) and his remarks on alot of this "digital
misery" goes like the following....

"I am a firm believer in this studio philosophy: if you can't hear it, it
doesn't exist. Ignore what the machine shows you and LISTEN. That goes for
VU meters as well as digital waveform displays."

"Recording engineers need to LISTEN again instead of LOOKING."

"Values above the threshold are spat out at 32767. Ergo, you have a 
shitty sounding square wave brought on by a system with zero headroom."

"On tape, zero was an absolute reference which could be measured exactly. 
You then decided how far above zero to allow your recording. If you 
liked the result, you went with it. And tape being what it is, it is 
very forgiving and will naturally compress hot signals."

"In digital, zero means NOTHING. It means 'don't go past here because this 
is how we built our system, and if you do you're in square wave land.'"

"This is a problem. A generation of engineers is growing up with no basic
tracking skills because of this. They keep using their eyes instead of their
ears."

"The engineers who design this shit are even more guilty of that."

[Incidentally, he is a die-hard "Old School" (not host-based) Pro Tools
Snob, though you might be tempted think he's some analogue dinosaur.]

Back to Malcolm here.  There's NOTHING that says digital audio devices can't
have headroom, but it means calibrating your levels to avoid peaking above
-3dB or whatever the headroom you want to reserve.  There's the human
"greed" instinct of course which resents this sacrificing of come
resolution. [in a digital sample, this is about 1/2 the values!]  

It's this very greed which allowed The Dark Lord to ensnare the Kings of Men
with The Nine to start with.  You can be sure the Witch King of Angmar liked
maximum squeeze on his mastering projects.  Look what it got him in the end.

I think the best compromise of this is to provide dbx companders in a button
on consumer CD players, so that CD audio can be mastered properly with full
dynamics and unclipped sounds.  This way, when Joe Jughead wants his
compressed and clipped noise, it's just a button away.  Incidentally, I wish
I can say I claimed credit for this foul idea, but some college students
beat me to that.

Even The Dark Lord's mastering engineers didn't believe in clipped
waveforms, they preferred Quality,

=MB=
-- 
A focus on Quality.