Audio over HDMI in Game Mode is crackly and distorted

[Pavestone24]

I just installed a fresh copy ChimeraOS (latest version, as of yesterday) on an older computer (i5-6500, RX480) and I am having trouble getting the HDMI sound working while in game mode. It's a completely clean install, here is what I've done and tried:

1. Log into steam
2. Noticed that UI sounds were not working. Went into Audio settings, changed device to HDMI and turned Steam's audio volume to the max.
3. I noticed I was getting some UI sounds from steam, but sometimes they would not play at all, and when they did it was distorted and crackly.
4. Downloaded a couple of games to try out the in-game sound. In both, the sound was barely there, and crackly and distorted when anything at all came out.
5. Switched to desktop, fired up Steam, and switched to Big Picture mode. I didn't notice any UI sounds (I don't think Big Picture uses UI sounds), but sound works perfectly in-game.

Honestly, I would just stay in big picture mode, but it's very laggy, and certain games do not use full screen or have proper controller support when I'm in desktop mode, so I'd much rather get the audio in Game Mode working.

For more context: I was previously on bazzite-deck, and had the same issues there (but worse, Bazzite would generally not play any sound at all, and games crashed more frequently on Bazzite.) This may be related to issues #499 and #939, but I haven't been able to find a working solution to either.

Thanks very much for any help you can provide!

EDITED TO ADD: Just a bit more context, the file I downloaded and installed is chimeraos-2024.09.20-x86_64.iso. I see from the changelog that in version 46-2 (released 2024-08-10) there is a note: "Added kernel patch to fix HDMI audio on AMD". Whatever that fix was, it's not working for me.

Also just wanted to add -- I checked the volume in alsamixer, it was not set to 10000%, so it's not that bug. I set it down to 75% just in case, and the sound in game mode does not cut out as often, but it is still weird and distorted (but not obnoxiously loud).

[Rosoboy19]

I experienced this issue on a new Chimera install this week and was able to resolve it by switching my HDMI input to “Standard” mode. If I used “Enhanced” or “Auto” the HDMI audio would crackle and distort in Game Mode (but not desktop mode). Hope this helps.

[Pavestone24]

Thanks for this! Can you tell me where that setting can be found? I assume it's accessible via the desktop, but I don't see it...

[Rosoboy19]

It’s a setting on my television. I have to go into the settings for the HDMI input to change it.

[Pavestone24]

Ah, got it -- unfortunately, this didn't fix it for me. Thanks for your help anyways!
I think I'm just gonna buy some cheap external speakers for my box at this point.

[NeroReflex]

Ah, got it -- unfortunately, this didn't fix it for me. Thanks for your help anyways! I think I'm just gonna buy some cheap external speakers for my box at this point.

Are you in unstable/beta software?

[dr-Fade]

I had this issue when connecting the new TV to the chimeraos box and entering the Game Mode.
Switching the HDMI audio to PCM mode in the TV settings resolved it for me.