A search was not completely helpful... I'd like to hook up my Xbox via optical cable to my reciever, which only has one optical input jack. No problem. How do I also hook up an HD cable box and get 5.1? Do they make an optical splitter with a "switch" on the side of it so I can either use my Xbox or watch cable? Can I run my HD cable box to my reciever via the co-ax input and expect 5.1? I'm not really sure what the co-ax input is... It looks like a regular RCA jack, only green. Please educate me! Thanks!