[alsa-devel] Recording sound from microphone isn't good working that playback sound is distortion.

[Mark Brown]

On Tue, Jul 31, 2012 at 03:00:16PM +0800, Xiaoyong Wen wrote:

> 		 3. Recording sound from microphone isn't good working that playback sound is distortion. 
> 		 #arecord -D 'hw:0,0' -r 48000 -f S16_LE -c 2 | aplay -D 'hw:0,0' -c 2 &
> 		 or
> 		 #arecord -d 10 -fdat test2.wav
> 		 I hear the sound is very distortion and low.
> 	     ~~~~~~~~~~~~~~~~~~~~~~~~~~
> 		 If I excute "amixer cset numid=9 3; amixer cset numid=7 31; amixer cset numid=87 on; amixer cset numid=6 31,31" command, and then volume is high.

This sounds fairly normal - microphones do need quite a bit of gain
applying to get useful signals.  I don't know what controls those are
(the control names are much more useful, the numids do change between
boards) but I would expect that microphone configuration wouldn't be
ideal out of the box and would need some tuning for your system.