Adjusting the L/R balance on laptop speakers

pendulus-maximus · 2015-06-25 23:36:02

HOKAY

So I have this hand-me-down Acer laptop that's got some mileage on it. The right channel speaker does not work for whatever reason. This is problematic when listening to music recorded in stereo. It features most prominently on old classic rock tracks -- the guitar solo will be on the right channel and the rhythm section on the left, so I only hear this little tiny faint whisper of the guitar solo.

Strangely enough, headphones work fine. I get both channels.

So my question is:

Is there a way to pipe both the left and right channels to the left speaker? If I were running the audio output through a receiver, I would just throw the balance knob all the way over to the left. Can I accomplish this with software? If so, how? Alsamixer does not appear to have this functionality.

Last edited by pendulus-maximus (2015-06-25 23:40:02)

Trilby · 2015-06-25 23:45:37

Adjusting the balance would do nothing of the sort - that would only increase the volume on one channel and decrease the volume on the other. You need to downmix the channels to mono. Check out the alsa wiki to adjust as needed, but something like the following should do in ~/.asoudrc

pcm.!default mono

pcm.mono {
    type route
    slave.pcm "hw:0"
    ttable {
        0.0 1    # in-channel 0, out-channel 0, 100% volume
        1.0 1    # in-channel 1, out-channel 0, 100% volume
    }
}

The ttable is the relevant part there - the rest may need to be adjusted. If Brebs or Emeres pop in they'll definitely be able to give more details - they seem to be our resident alsa experts.

pendulus-maximus · 2015-06-26 01:13:47

Arright, awesome! Thanks for the response. I'll give it a shot and see what happens.

To follow up: Would there be a way, then, to flip between different "profiles"--as it were--depending on whether the audio is going through the speaker or headphones? Or would I have to edit the config file each time I plugged the 'phones in?

Arch Linux

#1 2015-06-25 23:36:02

Adjusting the L/R balance on laptop speakers

#2 2015-06-25 23:45:37

Re: Adjusting the L/R balance on laptop speakers

#3 2015-06-26 01:13:47

Re: Adjusting the L/R balance on laptop speakers

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