Tried various things with .conf files above after getting root (/) filesystem mounted as rw, but still unable to get things working.

Used retroarch directly after stopping emulationstation manually, i.e.
retroarch --menu --verbose ; customretroarch definitely being read-in including the following audio settings. have confirmed that audio_device is @ 0,1 and modified the audio_driver with alsa too.

retroarch --features compiled with ALSA as expected, nothing else valid to use:

audio_enable = "true"
audio_driver = "alsa"
audio_device = "hw:0,1"
audio_sync = "true"

simply getting an "failed to initialize audio" error from retroarch log:

[ERROR] [ALSA]: Failed to initialize... [ERROR] Failed to initialize audio driver. Will continue without audio.


decided to take a good look at osmc config with retro and what its using:
audio_driver = "alsathread"
audio_resampler = "sinc"
audio_device = ""
audio_sync = "true"

I emulated this in recalbox, and the errors in retroarch stop with the following in the retroarch startup as in osmc

[INFO] ALSA: Using signed 16-bit format.
[INFO] ALSA: Period size: 384 frames
[INFO] ALSA: Buffer size: 1536 frames

so figured I was onto something, however still no sound.

really just clueless now. remember, I launch emulation in osmc (from kodi) and I start up a game... audio just works.

i suppose my next question is: is there something in kodi that launches stuff correctly or emulation station, or is this simply a recalbox 'startup driver problem' that doesnt recognize the audio correctly. can anyone shed light on this for me?