[LAU] Sample rates

[Ralf Mardorf]

On Thu, 2013-02-14 at 20:32 -0700, Bob van der Poel wrote:
> Now, if I have an app like audacity set to 48K does it (or jack?) send
> a message to the box to enable 48 (or 44.1)? If that is the case, I
> assume that using 44.1 or 48 should have the identical latency issues?
> 48K should send a bit more data back to the computer?

All audio devices I know automatically are set to the sample rate set by
alsa, 'jackd -d alsa --help'.

No, the latency will differ for different sample rates:

512 samples / 44.1 kHz = 11.609977324 ms
11.609977324 * 2 = 23.219954649 ms ≈ 23.2 ms

512 samples / 48.0 kHz = 10.666666667 ms
10.666666667 * 2 = 21.333333334 ms ≈ 21.3 ms

Higher sample rate = more data at equal bit depth.