[LAU] digital voodoo: master fader should be set at 0db

Arnold Krille arnold at arnoldarts.de
Wed Apr 14 17:39:44 EDT 2010


On Wednesday 14 April 2010 23:17:05 micromoog wrote:
> On Wed, Apr 14, 2010 at 3:06 PM, Arnold Krille <arnold at arnoldarts.de> wrote:
> > Going into psychoacoustics is not really contradicting the "machines
> > can't measure it, still it exists". Machines can measure the frequencies
> > the human
> > ear can't hear but which still have an effect how we perceive the sound.
> > Only
> > the effects aren't looked into as deep as the frequencies below 20kHz
> > are. To
> > the result that most scientific research wasn't able to give reliable
> > results.
> > Which in turn makes most audio people discard frequencies >22kHz light-
> > heartedly. And they are right as the scientific (thus neutral) proof of
> > the effect of the frequencies below 22kHz is _much_ greater then above.
> > That doesn't deny the psycho-acoustic effects, it only ignores them for
> > the sake of
> > bandwidth, reliability and cost...
> Sorry to pick on you, but this is the piece of audio voodoo that irks me
> most of all.  There is no evidence I'm aware of that supports the idea that
> ultrasound has any effect whatsoever on human perception of anything.

I am not into that field of science but as far as I know there is research in 
that there are effects when >22kHz frequencies are in a normal sound, it makes 
a different effect then when the signal is clipped frequency-wise at 22kHz. 
Difference between a violin played inside the room you are and a violin-
recording you hear from CD.
But I don't actually know if that is proven enough or if its voodoo...

> If you doubt this, as many people do, try the experiment I used to prove it
> to myself:
> 1) Set up some good synthesizer software (e.g. SuperCollider, csound,
> PureData, etc.)
> 2) Generate pure sine tones of increasing frequency until you reach the
> point where you can't hear it (for me this point is just over 16k; for an
> older colleague of mine it's just under 14k) (warning: this revelation can
> be depressing)

Back-nitpicking: You have to go down with the frequency if you want to test 
your upper frequency limit. Otherwise your ear will claim that it hears 
something after you actually stopped hearing it. Or switch the frequencies 
randomly... Similar to phantom-images in your eyes, your ears can hear 

> 3) Start cranking up the volume.  Your VUs will tell you it's there . . .
> your amp clipping lights will tell you it's there . . . your dog that runs
> screaming from the room will tell you it's there . . . your exploding
> tweeters will tell you it's there . . . but you won't hear it.  Ever.
> 4) Now that you've got this horrifyingly loud sound blasting throughout the
> room, live your life.  Watch some TV.  Listen to some music.  You won't
> notice anything.  Better yet, have someone else turn it off and on
> periodically, and you note when it's on.  You won't reliably be able to.

What if you you realize that you feel better with that frequency on?
If its only you out of 100 people, its voodoo. If its 99 out of 100 people, 
its a fact proven by science.

Might be I feel better with such a tone around me. Because I don't like dogs 
that much. :-P

> So . . . if an ungodly pure tone at, say, 18k has no impact on my senses at
> all, ain't *no way* that the "air" of a symphony at 30k will.  Until some
> unbiased A/B/X tests start showing up that prove otherwise, ultrasound is
> pointless in music.
> I'd love to be proven wrong here.

Might be you are proven wrong here. As others claimed in this thread, the ear 
is not linear (not even logarithmic in every aspect). Might be that 18kHz 
don't affect you while 30kHz do:-)

> Footnote: Yes, there's a valid argument for higher than 44.1k when
> recording, which involves the filters in A/D converter hardware.  There is
> no argument for it in the listener space.

Actually I am not defending the "you have to record at 192kHz, everything else 
is crap". From my experience, 48kHz is enough. And cheaper on disk-space...

Have fun,

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