I just popped in to say good luck. Sorting out audio issues has been the bane of my linux experience. It’s not an easy nut to crack.
I’ve been messing around with adding background music to ES. I have to do some funky workaround with MAME. I’m not exactly sure why, so all I can really do here is confirm that MAME is in fact handling audio differently than most of the other emulators.
I do believe that caver01 is on the right track though. The secret sauce is in fixing the Alsa issues. Maybe remove Alsa completely, if possible, and try to set it up fresh?
^^ my other hobby