rlhjr34

I have the Ultra 2 system and I get a hum in my center channel speaker when I connect my system. I've used two different shielded sub cables from my receiver to the KA1000 amp. I've even tried both inputs on my KA1000 as well. I've run the test pattern on my receiver for my speakers and there is a signal going to the subs. When I disconnect my sub cable from the KA1000 the hum goes away. However I've definitely seen them work when I run the test pattern. When a movie starts up I get a hum in my center speaker again and I can't get rid of it. I've tried the phase control on the amp and that doesn't do anything to fix it. Do I have a ground loop issue? How do I fix it if I do? Thanks!