I bought a new Onkyo 7.1 Home Theater system yesterday and set it up with my computer. I used an optical cable from the sound card, HT Omega Strike 7.1, to the Onkyo receiver. In Windows 7, when I open the Xear 3D options, the only way I get sound out of the back two speakers is if I have S/PDIF Output set to 'PCM'. If I change it to Dolby Digital Live or DTS I only get sound out of 5 of the 7 speakers. I'm far from a sound expert, so I'm not sure if I'm doing something wrong, or if it's just not possible to do what I want.