[bayindirh]

I need to read the ALSA bugfixes because of PA to see and believe that.

On the other hand, I used multichannel audio since the last 20 years or so, on Linux, and it always worked with what I have. First with Live and Audigy, then with an Asus card.

No, pipewire is much more gentle on how it handles and takes the streams from other applications. It doesn't make an heavy-handed attempt to make it is also replacing ALSA and drivers at the same time. It's a much thinner layer and works what it should do. Most importantly it doesn't alter the streams it goes through it.

(Sorry, but upmixing a good stereo sound source to 5.1 is just butchering the sound. The resulting sound stage is an abomination of what it should be. For a musically inclined person (read: ex-orchestra player), it's just torture. It's so wrong on so many levels.)