Quadraphonic (4 channel) sound issue on Windows - missing 4th channel.

Unity Engine
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1

I’ve been working on an audio-visual installation running on a Windows PC which will use a 4 channel audio interface for its audio output.

In Windows this is configured as a quadraphonic device and all 4 channels work when previewing the sound in the Import Settings inspector, but while running the project (both in the editor and as a standalone build) the 4th channel is silent (channels 1-3 work as they should).

Running it through an Audio Mixer in the editor and watching the Master levels also shows channels 1-3 playing but channel 4 silent.

While developing it I used a 5.1 soundcard and Unity had no trouble playing 4 channel audio files (with channel 3 and 4 being assigned to SL/SR), also setting that same soundcard to quadraphonic mode in Windows reproduced the same issue with the missing 4th channel as the 4 channel audio interface.

Is there an issue with quadraphonic sound support currently, or is there some setting I have missed?

Thanks.

2

Another possibly related thing I just found, I forgot to switch the project speaker mode back to Surround 5.1 from Quad while testing on my 5.1 sound card, yet 5.1 samples played back in 5.1 mode. Checking the Audio Mixer only shows 4 channels (with channels 5 and 6 not visible but playing back fine), and AudioSettings.speakerMode returning Quad at runtime.

Changing the speaker mode to stereo causes 5.1 samples to be mixed down to 2 channels so the setting is working, could the problem be that Quad is incorrectly running in 5.1 mode?

3

Same issue here:

I have 2 test files with sound on channels 1 2 3 4 (quad file) and one with sound on 1 2 5 6 (5.1 file) and both play their sound on the left and right rear speakers when windows is on 5.1

With windows set on quad, my audio files don’t play on the right-rear speaker…

Please advice (and please don’t say never use a quad audio card?)