Well, you also have a coax digital audio input. So, if any of your sources have a coax digital audio output, you could at least take advantage of that.
As I see it, you'll have three digital audio sources:
- Blu-ray
- Cable box
- Xbox 360
If you watch over-the-air broadcasts, then you'll want to connect your TV, too. For now, I'm assuming that you watch everything through the cable box.
So, three sources and two inputs. Does the cable box or Xbox 360 have a coax digital audio output?
BTW, have you considered getting a different all-in-one system? Just asking.