[PlanetCCRMA] delay test

Fernando Pablo Lopez-Lezcano nando@ccrma.Stanford.EDU
Wed Apr 14 19:12:00 2004

> The problem is that I need an external soundsource as a reference signal. 
> What I did was this :
> mono source to stereo source
> left channel directly to left channel of recording device
> right channel sent to ALSA-PC LineIn
> line out of PC sent to right channel of recording device
> The gap between the left and the right channel indicates the delay BUT the
> ALSA PC sends the input directly bypassing the soundcard which is why I
> measure a delay of 0 ms (same signal of course). 
> When I´m muting the capture channel the signal might get captured but I
> doesn´t appear on the master anymore.     

You have to use alsamixer (or gamix) to see which switch and/or level
controls the direct "monitoring" of the input to the output. Which
soundcard is it that you are using?

-- Fernando