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).
