3

I've found that I can use pavucontrol to control the volume in my left and right speakers independently, by un-clicking the "lock channels together" button. However, I can't find a setting to let me send different output to the two speakers - i.e. I want to play audio track A on my left speaker and audio track B on my right speaker. How do I do this?

2

With sox(Sound eXchange); if you have two files with similar bitrates or already set to one channel:

play -M A.mp3 B.mp3

Otherwise:

play -m "|sox A.mp3 -p remix 0 1-2" "|sox B.mp3 -p remix 1-2 0"

What this does is simply play the output of two sox commands which output to pipe(-p); the first one remixes L/R to R and the second remixes L/R to L. If you're playing sources with different gain values etc. you may need to adjust the two sox commands(gain etc.).

  • play FAIL formats: no handler for file extension `mp3' - need libsox-fmt-mp3 as well for this. – Benubird Nov 21 '14 at 7:49
  • @Benubird Maybe you need something like libsox-fmt-all or something like that; are you on Ubuntu? – user44370 Nov 21 '14 at 7:55
  • Also, does not work: the default functionality of -M is to play the given files in sequence, not in parallel. You can tell it to mix them, but from what I can see that doesn't actually play them on separate channels, it just plays them both on one, AND will only work if they have the same sampling rate. – Benubird Nov 21 '14 at 7:56
  • I'm on ubuntu, yes. But reading the man for play seems to say that mix just plays them on top of each other. – Benubird Nov 21 '14 at 7:59
  • @Benubird When you get a chance take a look; this should work. Thank you! – user44370 Nov 22 '14 at 19:20
0

So, I found a solution. Turns out that if I run the media via two separate processes (i.e. "play a.mp3 &; play b.mp3") then pavucontrol will allow my to control their volume separately. I can unlock the channels, set one to 0% left, the other to 0% right, and this will work.

However, I feel like this doesn't quite answer the question - it works for my use case, but I'm not sure it will be useful to future people who come here with a similar question, who are most likely looking for a way to do it without going through the pavucontrol gui. Something that I would appreciate knowing how to do (if possible) as well.

So, I'll leave this open for more answers, and only mark this one correct if I get upvotes to indicate that other people find it helpful (or no other answers).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.