Can confirm the following commands to setup simultaneous audio output in Plasma 6:
-
pactl list sinks short #will return the full names of audio sinks you need for the next command -
pactl load-module module-combine-sink sink_name=combined_monitor_sink slaves=<put name of audiosink 1 here>,<put name of audiosink 2 here>, channels=2 channel_map=front-left,front-right -
pactl set-default-sink combined_monitor_sink
note1: I do not have to set devices to “Pro Audio” mode, but that works too.
note2: this works reliably when done immediately after booting the machine.