Mono, please

It bugs me when I hear stereo audio that’s only using one channel. By default Gnome alsa mixer didn’t include a ‘mix mono’ option, so I figured out how to do so via ~/.asoundrc

Edit: I’d just like to make clear this post has nothing to do with the FLOSS port of the .NET base.

For anyone who read my recent post about YouTube censorship, xenutv, and Scientology, you may have viewed the Jason Beghe interview conducted by xenutv.

That video commits one of the biggest sins in online video in my book, one I wrote about way back in May 2006 (A Word on Audio), having stereo sound with only one channel of audio. I listen with headphones, so it’s like I’m deaf in one ear when they pull that crap.

Unfortunately my new computer’s sound drivers are a little different. Mainly, there’s no ‘mono mix’ checkbox in Gnome Alsamixer, for reasons beyond my comprehension. But, alsa is highly configurable if you take the time to figure it out. Which I have:

  1. Create a ~/.asoundrc if one does not exist.
  2. Edit it per below.
  3. Save it.
  4. Restart any sound-using programs.
  5. Rename the ‘pcm.!default’ to something (pcm.notdefault) & repeat 4 to disable mono.

The code:

pcm.!default {
  type plug
  slave {
    pcm "d"
    channels 1
pcm.d {
  type plug
  slave {
    pcm "hw:0,0"

This assumes your default audio device is hw:0,0

If it’s not, you’ll need to figure out what it is. One way to do that is to study the output of:

aplay -Ll

There’s probably some way you can add a checkbox, or make this more automated. I’ll look at that later. For now I’m just glad to have the option of monaural audio when I need it. Upon reflection having monaural audio is also a boon to people who actually are deaf in one ear; they can then hear the second channel mixed in.

I just wish I could figure out how to add this as a setting in alsa mixer so it would be a little simpler to switch.



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