I have issues with getting the sound in the Pimax crystal to work properly. The game sound might not be there but coming out of the external speakers, but strangely enough ATC I can hear in the Crystal. Best fix is to close down MSFS, make sure you can hear sound from another source like YouTube whatever, and try to load MSFS up again. Anyone experiencing the same? and apart from always making sure that you start the Pimax headset and check the sound before you startup your MSFS is there some kind of fix for it? If I try to restart the headset or service it doesn’t help.
This may help. You have the option to specify sound output device for ATC:
BTW consider VATSIM, way better vs the simulated ATC.