4 channel audio not fully working

Unity Engine
,
1

Hi!
I’m trying to figure out how to do multi channel audio in unity, and it looks like something isn’t working correctly.

here is my setup:

  • Blank unity project (unity 2020.3.0f1)
  • Set project settings > audio > default speaker mode to “Quad”
  • Create a 4-channel audio clip with audacity (1 “click” on each channel, one at a time)
  • Import the clip into unity with default settings

7968651--1022070--upload_2022-3-16_16-56-31.png
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I don’t have an external sound card (yet) so I’m using VB-Cable as a virtual 4-channel output

VB-Cable provides a Control panel where I can see the levels for each channel.
Playing back the source file with quicktime, I can see the channel 1,2,3 and 4 levels moving as I expect.
However, playing back the imported audio clip in unity’s asset preview merges channel 1 with 3, and 2 with 4. The same thing happens when playing the audio in-game.

Another setup I’ve tried is the same as above, but setting up my computer to use an “aggregate audio device”:

With this setup, playing back the clip in Quicktime or in the unity asset preview works as expected (I hear the channels 1 and 2 through the Built-in output and “see” the channels 3 and 4 on the VB-Cable control panel).
Playing the clip in-game however, only the channels 1,2 and 3 seem to work. Nothing happens on channel 4 (Even using a unity audio mixer, I can see channels 1,2 and 3 “lighting up” but 4 stays silent)

I know changing audio config with unity opened is not guaranteed to work, so for every test I do, I quit and restart Unity.

I hope I’ve explained the issue properly. If not, I’ve attached a zip file with the test unity project (including the 4 channel audio track), and screen recording of different tests I’ve made. If you need more info, I’ll be happy to provide it for you

System:
MacBook Pro (Retina, 13-inch, Late 2013)
MacOS 11.6.2
16GB RAM
2,8 GHz Dual-Core Intel Core i7

7968651–1022040–unity audio bug.zip (1.6 MB)

7968651--1022070--upload_2022-3-16_16-56-31.png
7968651--1022070--upload_2022-3-16_16-56-31.png846×430 25 KB

2

this fixed it for me: https://thomasmountainborn.com/2016/06/10/sending-audio-directly-to-a-speaker-in-unity/

Channels 3 and 4 are for center and bass. you have to use channels 5 & 6 for back left and back right speakers.

3

Your link is broken. I have tried audio clips with audio on 1,2,3,4 and 1,2,5,6 and neither works. I still only get 1,2 and 3 during playback in Unity, but not in asset preview.