the 4311 only has rca connectors no xlrI can understand the ground loop but why is it only happening to 1 sub and not the other. They are both RCA plate amps. B&W ASW 855 is a 1,000 watt 15" driver and the Dayton Titanic is a 1,000 watt 15" driver. Confuse as to why the Dayton hums but the B&W does not. They are both using the same Y cable from the rear of my receiver. ifits a ground loop shouldn't both be humming? Just curious.