That shouldn't be a problem. Cables is cables, or at least cables enough to hear something if you're of the expensive cable persuasion.
How do you have everything hooked up? Does your receiver have a separate setting for 5/6/7/8 channel inputs? Mine does, but it's an H/K. I wouldn't unplug part of the 6 cable bundle to use as a digital cable (that would be a pain to put back, JohnK!), but if you've got an extra analog interconnect/coax/RCA cable/hanger with RCA plugs at the ends lying around, use that.
