Audio Audio Filter only works on 2 channels (5.1 Audio Installation)

Hey,

I'm a freelancer currently working on an 5.1 Audio Installation project and have been researching ways to work with multi-channel Audio in Unity.

My goal is to make a solution that allows tweaking the volumes of every channel of an AudioClip during Playback. (Realtime - not during creation.)

I achieved that using multiple AudioSources and by using a method from following blog:
https://thomasmountainborn.com/2016/06/10/sending-audio-directly-to-a-speaker-in-unity/

Now I was hoping I could create a more elegant solution using AudioFilter (https://docs.unity3d.com/ScriptReference/MonoBehaviour.OnAudioFilterRead.html), but after testing the AudioFilter seems to only work on two channels. Event function parameter "channels" is 2 even if the audio played has 6 channels.

Could not found anything about that neither in Docs nor in Forums.
Is there some magic I'm missing? Or is this a bug/feature?

Thanks.

 

if you change default output mode in project settings -> audio you'll get appropriate # of channels in filter callback

 

That solved the issue, Thanks!

I'll just set it by script using the highest driver capability.