So I got a new AV receiver and 3.1 speakers but I'm unable to tell by just playing snippets of content on Netflix and Plex if the 3.1 is actually working. I've tried setting the sound setting to PCM and SPDIF.
Sometimes, it sounds like the 3 speakers are just playing the same thing. When I press the wrong button on the AVR remote ("STRAIGHT"), only the center channel plays. Is there an easy way to play something in only left, only center, only right channel so I can test it out?
There are Audio Test Apps available for Android and Android TV that will allow you to test to make sure that everything is working as expected.
I used an App called "Sound Test for Android TV" (yeah, original name) on my MiBox 3 and was able to test each channel on my 5.1 SB.
I didn't try any others, because this one worked for me.
Hope this made sense and was helpful.
Best wishes and good luck!