I’m using PlexAmp on many devices (android phone, IOS, Linux desktop, and windows desktop) One very annoying thing is that on windows even if I choose system default audio output, which is a realtek quadriphonie audio output. it only output in stereo on my front speaker, no rear channel and in fact no subwoofer 
on the same PC if I play the same PlexServer and the same track in the webPlayer I have the full channel used! is there an option in plexamp I am missing ? or is plexamp using the audio driver a different way and not respecting my system default audio settings which I tripled check, and is 4 channels.
Best regards
There are 2 places in the Plexamp settings where you must disable “Downmix to Stereo”.
One is in Settings - Playback,
the other is in Settings - Playback - Quality
Speaker setup in Windows has to be set to 4.0 or 5.1 as well.
Carefully examine how your speakers are connected to the sound interface. If the subwoofer is fed from the front L and R speakers, you don’t have a 5.1 configuration, but a 5.0 or 4.0. The “.1” is the dedicated channel for the sub (or more correctly “LFE”).
The playback session has to begin with an actual surround audio file. Because if the first track is in stereo, then the internal audio chain of Plexamp will also only be in stereo for the remainder of the playback session.
You will need to stop playback completely (long press on the Pause button), wait a few seconds, then start playback of a surround file.
Ok thanks for the trick. But wouldn’t it be more simple and proper to add a simple option to upmix stereo to surround in the playback option?
Personnaly I don’t have a surround audio file in my library and even if I had one, I would have to start all of my playlist with this file
Regarding the number of related thread and questions about this surround problem, it would be so nice to have the clear option in settings.
Best regards
Apologies, I misunderstood your question.
Plex doesn’t do “fake surround”. If you want that, you either use an amplifier with surround processing,
or you tell Windows to simulate “3D room sound”. There should be something to that effect in the Windows sound settings.
