"GMX Transmitter" is for the USB only--you'll notice this because that option only appears when your base station is switched on. That's meant for chat audio, I believe. Also, USB won't give you 7.1 surround; only digital/spdf can. I'm using Win 8.1 too, and I can get game + chat audio running fine with the PLYR 1.
11/20/13 at 7:31pm