The cable you're using is, in fact, a coaxial cable. It's just of fancier sort. It refers to what's in the cable, not really what it does. RCA cables of any kind also qualify as coaxial, as do most interconnects.

As for the hum, these other fellows will have a better chance than I of clearing that up for you.


Pan TH-50PZ800U
Onkyo TX-SR805
Axiom M80 (2)
Axiom VP180
Axiom QS8 (2)
Axiom EP500
PS3, Harmony One