I have an nvidia gtx 1050 running on debian 9. I have 2 external monitors, one through Display port and one through HDMI. Both monitors output the sound just fine, but only one at a time. Is there any way to combine sound for both digital outputs?

I tried using Pulse audio preferences to add a virtual device, but that device is a bridger between the "Digital Ouput" (motherboard sound) and one of the HDMI outputs (whichever is currently enabled/active)

  • this is probably going to be dependent on your gfx driver. are you using the proprietary driver (what version?) or nouveau (what kernel version)? – quixotic Feb 4 '18 at 21:58
  • I have installed Nvidia X server, but I don't think this has anything to do with Sound. My kernel version: 4.9.0-4-amd64 – Seba Vasile Feb 6 '18 at 20:11

The "virtual device" in the Pulseaudio preferences adds a so-called "combined sink", module-combine-sink. The slaves property of that module determines the sinks it outputs to.

If you can't adjust that the with Pulseaudio preferences on your system, you can load and setup the module manually from the command line, with something like

pactl load-module module-combine-sink sink_name=combined sink_properties=device.description="Combined Sink" slaves=xxx,yyy

where xxx and yyy are the names of your sinks as seen in

pactl list short sinks

Details are in the module documentation.

  • I tried pasting the output of pactl list short sinks, but seems I am unable to properly format my comment. I have only one of the 2 digital outputs listed in pactl list shorty sinks, and it changes if I change the output device in pulse audio -> configuration. I would assume the GPU or drivers is unable to send sound to both monitors? – Seba Vasile Feb 6 '18 at 20:15
  • I think I was not clear enough. Under Pulseaudio Volume manager I have 2 devices, and HDA Nvidia, has 2 profiles, where I can choose either one output or another – Seba Vasile Feb 6 '18 at 20:28
  • Ah, the problem is that the default Pulseaudio profiles don't give you multiple HDMI sinks. See here for a solution to this problem. Unfortunately the solution isn't straightforward and needs quite a bit of fiddling with the Pulseaudio files. – dirkt Feb 7 '18 at 16:44

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.