how to fix low sound output on a lenovo t510 running linux with alsa

to increase the sound output level on a lenovo t510 running linux (all distro’s seem to be using the alsa sound system, these days), add the following to etc/asound.conf.

pcm.!default {
      type plug
      slave.pcm "softvol"
  }

pcm.softvol {
  type softvol
  slave {
    pcm "dmix"
  }
  control {
    name "Pre-Amp"
    card 0
  }
  min_dB -5.0
  max_dB 40.0
  resolution 6
}

a new control will appear, Pre-Amp, in alsamixer. adjust to suit.

test:

if the alsa speaker-test command is available:

speaker-test -c sine

if the alsa sound files are in the usual place:

+aplay /usr/share/sounds/alsa/Front_Left.wav+