[LAD] A little quiz about audio measurements...

[Robin Gareus]

On 05/28/2010 05:05 PM, Ralf Mardorf wrote:
> Chris Cannam wrote:
>> Why 1015 Hz?
> 
> Slew rate of card x's input op-amps?

Slew-rates of op-amps are higher by at least an order of magnitude:
off-the shelf cheap op-amps have ~ 10V/us. Fons' test signal may be
~50mV peak-to peak.
In reply to Olivier message Fons already stated that it's not an issue
with sampling. Besides there's usually a low-pass filter on each analog
input.

He probably choose 1015 Hz for aliasing: 48000/1015 or 44100/1015 is not
a common ratio. ~1000 Hz is also in the middle of the card's spectrum
and there's rarely sth. around your house that oscillates at frequency.

There may be more to it, though. Fons?