Hi Alessandro,
There’s a new audio system under OM 6.12, as you noticed.
I’ve put here a temporary update which will probably fix the output device selection:
https://forge.ircam.fr/p/OM/downloads/663/
=> I’d be happy to get feedback on wether it works or not, in order to eventually pack and distribute this update.
Mono files: yes. The audio framework now allows you to work and output audio on an arbitrary number of channels (depending on available audio drivers and interfaces). Mono files is a special case where you woudl generally want to output on all channels: I still need to fix this.
… and yes also, there is no more audio “tracks” for the moment: every sound has only an individual gain controller.
Jean