I was happily playing a game in my VM and noticed that audio channels were reversed. In testing front left sound is coming from the rightside of my headset and vice versa. Tested the same on Host, and it has the same issue.
Quick googling didn’t offer any solutions. Anybody else had this issue?
You have your headset on backwards. 
@His_Turdness Maybe this helps? Look at swap left & right channels.
https://wiki.archlinux.org/index.php/PulseAudio/Examples#Remap_left_or_right_to_mono
I don’t use pulse audio. 
Well i guess that doesn’t help then. What do you use then? Just alsa?
Yeah, just ALSA. Funny thing is that HDMI is not reversed. It’s only SPDIF/analog.
You can change it on alsa …not sure if that is going to afffect HDMI but i doubt it because i think you have to set each hardware individually.
Is there a setting somewhere for ALSA or do I have to do it via terminal? I’ve read something on arch wiki, but those instructions are not easy to follow.
After some digging it turned out that GNOME installs pulse by default, so I had it after all. Finally got my multi channel output reversed with this command (found it and copied it from ubuntu forums):
load-module module-remap-sink sink_name=reverse-stereo master=0 channels=2 master_channel_map=front-right,front-le>
set-default-sink reverse-stereo
I added that to the end of my /etc/pulse/default.pa
Now I’d like to make the same happen to my SPDIF. Or maybe even get 7.1 working, cause I use the SPDIF with my 7.1 headset.
You are on the right track. Here is some more info. It actually explains most of it in the file when you open it to edit it.
I take it back. Both channels play left and right, so nothing is fixed. 
Switched back to KDE. Audio seems to be working much better here. Maybe because I originally installed Antergos with KDE?
KDE sucks with 4K screens though. Can’t win everything…
Yes, i think there is always something that makes it not a perfect setup. I guess you just have to decide what’s more important to you and put up with the little issues that maybe can’t be exactly as you want. 
Got channels reversed now. It’s really dumb that you have to do it via terminal and can’t do it with GUI. And I’m not sure if this solution is permanent or not.
Added this line to my pulse config: load-module module-remap-sink sink_name=reverse-stereo master=0 channels=2 master_channel_map=front-right,front-left channel_map=front-left,front-right
Had to change the device in pulse GUI, so that it’s using my digital S/PDIF and not USB/analog, but at least stereo is reversed (set correctly) now.
Progress lost. I had perfectly working S/PDIF set as my default sound, but after wake from suspend the HDMI is set as default. It works, but S/PDIF was supposed to be the default. Now it doesn’t even show up in sound drop down menu under devices list. 
Edit: seems like you can either pick HDMI or SPDIF + analog. That’s dumb. I’d prefer SPDIF + HDMI. Or maybe HDMI & SPDIF combined. And both to have stereo channels set up correclty of course. 
Is there really no way to load more than 2 or 3 devices under sounds? Like let’s say:
-analog stereo
-digital stereo
-hdmi stereo
-digital stero + hdmi stereo combined
-digital 7.1
-hdmi 7.1
-digital 7.1 + hdmi 7.1 combined
I don’t think anyone is going to have a quick and easy answer for this. Unfortunately you’re going to have to read up on the technical aspects of the hardware configurations that are possible. Then it will have to be some good old trial and error to see what works and what doesn’t. I can only point you hopefully in the right direction.
https://wiki.archlinux.org/index.php/PulseAudio/Troubleshooting
https://wiki.archlinux.org/index.php/Advanced_Linux_Sound_Architecture/Troubleshooting
Quote from wiki:
Swap left/right channels
This is the same as "reverse stereo", where the left and right channels are to be swapped.
First, identify the card you want its channels swapped:
$ cat /proc/asound/cards
and use the name string for the device you wish to use (the one in square brackets, e.g. [Intel]).
Edit /etc/pulse/default.pa and comment out module-hal-detect and module-detect lines.
Search for the commented-out line that starts "#load-module module-alsa-sink", uncomment it and change it to
load-module module-alsa-sink device=hw:"device_name" channel_map=right,left
Restart the pulseaudio deamon by running
pulseaudio -k; pulseaudio -D
I’ve tried pretty much everything in “device_name”, but nothing makes a difference. Numbers, text, with or without quotes… nothing.
Well maybe just keep looking … & trial and error. 
Managed to lose my settings and not get it back.
Deleted all pulse and alsa configs that I could think of, reinstalled all alsa and pulse packages that I could think of. That got me back to be able to use my SPDIF, but only that.
But funny thing is… when I log into gnome, can pick any of my sound devices. AND I can pick a virtual surround device I tried to create in KDE.
This trial and error thing is bullshit. Might just reinstall the whole thing soon.
Reinstalled GNOME, deleted KDE, installed dcaenc(AUR) in GNOME. Rebooted. Now stereo is no longer reversed!
I also have now the option for digital surround 5.1 under S/PDIF. Sadly, it doesn’t work. But I’m fine with that for now. At least stereo works correctly. 