Ok Will try that.
I did discover that with subs on and rca attached, but not connected at receiver, I was getting slight hum (subs are completely silent wen powered on and no rca attached). If I ran a wire from the center wall outlet screw (ground) to the metal of the amp chassis, the amp went completely silent. What does that mean?
So then, with receiver and sub connected with rca cable, I did the same thing with the denon. I touched the center wall outlet screw to the denon metal chassis (which is on another outlet across the room). Rather than the sub going completely silent as before, there was a very loud hum. What does that mean?
THANKS EVERYONE FOR THE HELP! Electricity is still like magic to me, lol