[LAU] Pro Audio? OT rant.

Fons Adriaensen fons at linuxaudio.org
Sun Dec 23 10:45:27 UTC 2012


On Sat, Dec 22, 2012 at 08:53:10PM -0500, Thomas Vecchione wrote:

[ about using 44.1 kHz sample rate ]

> If you are going to CD only, it removes the need to do a sample rate
> conversion, which obviously means less noise, and while there may
> certainly be some differences in audio quality, some people believe
> the difference from said conversion is greater than the difference
> in audio quality form 44.1 vs 96, etc.

Some people believe the strangest things. That doesn't make those
things true.

SRC amounts to applying a low-pass filter. That's it. There is no
other magic involved. The fact that this filter is producing output
samples at a rate which is different from the input sample rate does
not change it in any fundamental way. It just means using different
coefficients, which are no better or worse than those used by a 1:1
rate filter.

The operation will add some round-off noise, but no more than a simple
EQ or even a fader. That noise will be at a level at least 40 dB below
what will be added by reducing to 16 bit for a CD. Which means it makes
a difference of less than 1/1000 of a dB, if anything at all. It does
not add distortion or degrade the signal in any way. If you're looking
for that, you'll get a zillion times as much by using even the simplest
dynamic effect.

Given that most audio interfaces will perform better at 48 kHz than at
44.1, if there is any significant difference at all you're probably better
of producing a CD at 48 kHz and converting it to 44.1 right at the end of
the chain, the same place where you reduce to 16 bit and add dithering,
for example in Ardour's export dialog.

There is no good reason to use 44.1 kHz *ever*, except for the signal
stored on an audio CD.

> Not to mention that most sessions I find online that I give to my students
> for assignments are still exported stems at 44.1 so obviously I am not the
> only one that still uses it professionally.

True. In particular electro-acoustic composers using Max/MSP on their MACs
all seem to use 44.1 kHz, it's a continuous source of trouble at the LABEL
and the CdS. Must be something with the defaults of that SW or system. In
some cases they weren't even able to switch to 48 kHz. 

-- 
FA

A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)



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