Instead, the proposal is to make them as 2 active speakers which needs:
- a custom ALSA coding to split a stereo signal into separate left and right channels; this may or may not work?
- Sending left and right channels to 2 separate USB ports, and assume that the 2 USB ports remain in synch
- Converting USB output to optical; requires 2 USB cables & 2 optical cables plus 2 converters
A lot of effort with a complicated setup, which may or may not work... Not sure this is a good idea?