5.1 audio on unity 5.6?

Switched my project speaker mode to 5.1 audio and see the mixer has 5.1 channels. I can see the various levels as I play sounds under windows in the editor. However under Linux I only seem to get stereo.

Debug.Log("Caps: " + AudioSettings.driverCapabilities);
Debug.Log("Speaker mode: " + AudioSettings.speakerMode);

where caps is stereo and speaker mode is Mode5point1 in the Linux log.

I have tried pulseaudio+alsa and just alsa by itself. Every default is set to 6 channel/5.1 sound and from the command line, speaker tests play correctly out of every configuration I've tried. But Unity doesn't see anything but stereo. Tried 5.6.0f3 and 5.6.2p4 with the same results. Running Ubuntu 16.04.03 LTS and is up to date via apt update/upgrade/distupgrade - kernel is 4.4.0-91. We do run a very minimal install that has a bare bones X setup and not a full desktop. We run in kiosk type environments so keep everything as minimal as possible. I can see in the unity logs that it is seeing pulse or alsa depending on which way Linux is configured.

Is there some trick or setting that I'm missing? What is Unity looking for from Linux to enable 5.1 audio?

 

I am also running into this issue. We're building a game which must play certain sounds on specific speakers. We have the game outputting to the correct 5.1 channels on Windows, but not under Linux. Does anyone else have any specific information on this?

Additional note: I have tried testing this on Ubuntu and Mint with the same problem experienced on both. The project is currently being built with Unity 2017.3.0f3.

 

I sent in a bug report on this issue. You can track updates here: https://fogbugz.unity3d.com/default.asp?1027819_lp56ls2e11r2n22q