[MPlayer-users] high-pitched sound during mencoder recordings

[James Lancaster]

> Yeah, the signal coming out of a microphone has to be amplified
> tremendously to reach standard analog audio levels.  You were pushing a
> signal that was already that strong into the mic input, which means you
> were overdriving the mic pre-amps, resulting in clipped output from the
> pre-amps to the circuitry for standard levels.  The filters in the pre-amp
> (and probably also in the standard circuitry) filter out some of the higher
> levels of harmonics (i.e. the high odd numbers that make square waves "more
> square"), which you then hear as a continuous ringing noise as the removed
> components leave lots of high frequency remnants.
>
> If anybody wants to reply and make my response more technically correct,
> feel free to.  If you can correct my understanding of the goings on
> described above, I won't be offended.
>
> Glad you found this one cause I was curious what the heck could happen in
> software to do this.  Glad it wasn't the software.
>

Still doesn't explain my problem directly using the btaudio driver... Does 
anyone else using btaudio have this problem?