[LAU] M-Audio fast track pro mic input fails with smaller buffer size

[James Harkins]

At Sat, 27 Oct 2012 16:18:43 +0800,
James Harkins wrote:
> Has anyone else had this problem? For some pieces using live mic input, I wanted to reduce latency
> by pulling the Jack IO buffer size down to 512 samples from the default 1024. (I also tried 256
> samples, but that just made Jack crash.)
> 
> But with the smaller buffer, the mic gets an additional 30-40 dB of gain, making the input
> unusable. If I turn the preamp on the fast track down very very low and speak quietly into the
> mic, the sound comes through without obvious distortion or glitches, so it doesn't seem to be an
> xrun thing. But it distorts very easily and very badly.
> 
> If I switch back to 1024 samples, the problem disappears.

Just reconfirming this issue -- with 512 samples in the hardware buffer, the noise floor was about -20 dB. At 1024 samples, it was -70 dB.

Baffled (and, I guess, resigned to 46.4 ms latency in my concert...),

hjh


--
James Harkins /// dewdrop world
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