Re: Problems when audio capturing with headset

[Florian Kulzer <florian.kulzer+debian@icfo.es>]

On Tue, Apr 21, 2009 at 21:57:38 -0300, Daniel Bareiro wrote:
> On Tuesday, 21 April 2009 19:32:15 +0200,
> Florian Kulzer wrote:
> 
> > > > [...]
> > > >
> > > > What output do you get for this:
> > > > 
> > > > cat /proc/asound/{pcm,devices}
> > > 
> > > This is the output that I've obtained:
> > > 
> > > # cat /proc/asound/{pcm,devices}
> > > 00-01: ALC662 Digital : ALC662 Digital : playback 1 : capture 1
> > > 00-00: ALC662 Analog : ALC662 Analog : playback 1 : capture 1
> > >   0: [ 0]   : control
> > >  16: [ 0- 0]: digital audio playback
> > >  17: [ 0- 1]: digital audio playback
> > >  24: [ 0- 0]: digital audio capture
> > >  25: [ 0- 1]: digital audio capture
> > >  33:        : timer
>  
> > OK, the capture channels for this chipset are listed, but it is not
> > clear to me what their associated alsa mixer channels are called. Can
> > you paste the complete output of
> > 
> > amixer
> > 
> > on http://debian.pastebin.com/ (or a similar site) and post the link
> > here?
> 
> Interesting... I didn't know this site. This is the link:
> 
> http://debian.pastebin.com/m5c8e07e

Here are some guesses/suggestions:

Try to set this control to 'Mic':

    Simple mixer control 'Input Source',0
      Capabilities: cenum
      Items: 'Mic' 'Front Mic' 'Line' 'CD'
      Item0: 'Front Mic'

Try to reduce the volume of some of the channels, such as "surround",
"line", etc. Cranking up so many playback channels might overload the
hardware and trigger some mechanism that dampens everything.

Try to turn off capture for channels that you do not need while testing
the microphone, e.g. "IEC958", "Digital". Experiment with "Mic" and
"Front Mic" one at a time while reducing the volume on the other one.

Check with "arecord" if you can record from the microphone and look at
the recording with, e.g. audacity, to see the level of the signal and if
it is clipped. You can first try to record your normal playback to get a
feeling for how the capture controls and cvolume levels work.

-- 
Regards,            | http://users.icfo.es/Florian.Kulzer
          Florian   |