[Bug 275998] Re: internal mic capture very low volume when routed through pulseaudio

Marcus Granado mrc.gran at gmail.com
Sun Dec 28 17:03:46 UTC 2008

I've just moved to Intrepid (alsa 1.0.17) on a Dell Inspiron 1720 with
Intel audio (00:1b.0 Audio device: Intel Corporation 82801H (ICH8
Family) HD Audio Controller (rev 02)), and I was having exactly this
same problem: my internal digital microphone on the top of the screen
would only capture my voice if I shouted.

I was able to quickly fix it by modifying my /etc/asound.conf. The idea
was to use ALSA's softvol dB-gain plugin to do a software mic boost and
pipe that to a new pulseaudio device "pulseboost" that can be used by
Skype etc.

After adding those lines below and rebooting, you should see a new
slider called "+50dB Mic Capture Volume" in gnome-volume-control's
Recording tab (if you don't see it, go to Preferences and check it).
Raise it to maximum (+50dB), or a bit below that in case the maximum
value clips your voice or captures too much noise in the environment.

In my case, Skype was able to list a new device named "pulseboost" in
its Options configuration dialog's SoundDevices tab. If you choose this
device for SoundIn, Skype can benefit from the +50dB softvol mic boost
in gnome-volume-control. I also chose it for my Skype's
soundout/ringing, but I think that's not required.

Is there a side-effect to this? Well, I guess that with this setup you
can only use the mic at one application at any time, because it directly
accesses the mic's hw:0,0, but at least you have a huge mic boost in
that application.

### my /etc/asound.conf:
pcm.pulseboost {
    type asym
    playback.pcm {
        type pulse
    #software gain upto 50dB for digital microphone
    capture.pcm {
        type softvol
        slave.pcm "hw:0,0"
        #slave.pcm "pulse0"
        control {
            name "+50dB Mic Capture Volume"
            card 0
        max_dB 50.0
ctl.pulseboost {
  type pulse

I also added the line 'load-module module-alsa-source device=pulseboost'
to my /etc/pulse/default.pa, and renamed my ~/.asoundrc to avoid any
conflicts with my previous alsa configuration, but I think that's

That would probably work with Hardy, Gutsy, Jaunty etc as well. Please
let me know if that works for anyone here.

internal mic capture very low volume when routed through pulseaudio
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