I went thru the same thing, except I solved it in reverse order. Chassis ground on sub first, then the axiom isolator. All the hum is gone, but on weak cable signals I get weird lines in the JVC with every bass hit. Not a problem on HD feed from the cable or DVD (optical), but strange still. I've got the power lines separated from signal lines as best as possible, and using XLR cables from the pre-pro. I'll eventually get it cleaned up... but at least it doesn't hum.

Scott

Scott

My HT