Using the XAC hasn't been the most intuitive experience, maybe that's due to my lack of understanding on the subject of audio equipment, but after tinkering with it today I think I may have figured it out, tell me if I'm warm.   From the Main tab, the Audio Channel drop down is...

First time poster here so let me say thanks in advance for any help you can offer. I used to think that 5.1 or 7.1 through headphones connected to a motherboard audio out or sound card was as simple as plug and play. I'm seeing now that maybe I was wrong. Here's where I am with the whole thing...