It's really silly that OBS doesn't support multichannel audio input (splitting it into multiple audio sources)... it makes the OBS mixer useless for mixing audio in sync! ;;
If you mix all audio outside of OBS (like I do) it works well, but then you can't record split tracks...
Most people will tell you to use something like VoiceMeeter (on Windows) to send audio via separate virtual devices to OBS... but that doesn't keep them in sync since OBS considers them completely independent so there is a random delay offset between them (I tested it).
@wuest Yeah, that doesn't guarantee sync between tracks but at least you can fix it in post if you need to... I did something similar for Cyan's stream just now (one track full mix, one track voice only).
@scherzog That's the problem, if you have separate instances of stereo streams there is no guarantee that they are synced together... there needs to be something on the OBS side that takes a synchronized multichannel input natively and splits it into sources/tracks in a way that guarantees the sync is preserved, but I don't think that exists...
@lina Aah, yes. I wonder if OBS itself supports multichannel streams? Would be nice if it was just a matter of improving the plugin to accept arbitrary channel configurations.
@scherzog OBS supports routing to separate tracks, so that is in some way a "multichannel" concept... but I don't know if it supports it at the source level. It might need some core code changes...
@imikoy I've done that before ^^;; though for streams it's overkill, might as well just use jackrec and record a parallel multichannel wav for each stream.
BTW, audio monitoring also has a random offset in OBS (since the monitoring path is completely separate from the stream path). The monitoring mix you hear is not the same mix that goes out to the stream!
Basically I only use the OBS mixer for stuff like the intro/waiting screen BGM (where I don't care if it's in sync with the mic). Everything else including my stream BGM gets mixed in outside of OBS ^^
@lanodan Depends on your setup, but at least on Windows definitely enough that I can tell listening to the mix when singing karaoke and stuff like that.
If the underlying audio device is the same at the end of the day then at least it should not drift over time during normal usage. However, if there are any glitches due to CPU overload or things like that, they could cause the sync to change suddenly if different sources skip different amounts of audio.