Coax and optical can only handle 2 channels of PCM audio. To get surround from a PC, you need 5.1 PCM, which you can't do with a single wire.

Confused by terms like Linear PCM 7.1 Ch. 96 kHz, Bitstream and Dynamic Range Control? We help you make all the right audio settings in your PS3 right here.

Greetings, Does YouTube (not YouTube TV, I don't have that) actually support 5.1 audio? It says it does and I can find posts elsewhere that say it works ...