Once diagnosed get rid of the cheater plug. I also found a power conditioner with a grounding screw connected to your avr/processor grounding post will eliminate any further hum. I believe the real issue is all manufactures need to use 3 prong plugs so everything grounds to the electrical system not the equipment that is grounded...

You can use a cheater plug with no problem. Make sure it is non-polarized so you can reverse it to see which direction gets rid of the hum. If hum remains with either direction, perhaps there's a ground issue somewhere else in your system.

Outlaw#9 wrote: Once diagnosed get rid of the cheater plug. I also found a power conditioner with a grounding screw connected to your avr/processor grounding post will eliminate any further hum. I believe the real issue is all manufactures need to use 3 prong plugs so everything grounds to the electrical system not the equipment that is grounded...

Do you mind sharing what the conditioner is? Ironically, one of the SS XXL’s I bought was used (just shy of mint), and it has a three prong plug. But I just bought a brand new one on Saturday, and it only has a two prong plug. Both of them slightly hum. I will pick up the cheater plug after work some time this weekend.

Panamax MR5100, ground anything that does not have a 3 prong plug to it. It will change your experience completely. Audio and video will be amazing crystal clear. I have 2 of them each connected to separate 20 amp outlets. Some would consider what i have excessive. But I can watch a movie at full tilt and not even strain my system. My neighbors 5 acres away at least cant hear it too much....

HTNUT1975 wrote: Ironically, one of the SS XXL’s I bought was used (just shy of mint), and it has a three prong plug. But I just bought a brand new one on Saturday, and it only has a two prong plug. Both of them slightly hum. I will pick up the cheater plug after work some time this weekend.

Really, a new SuperSub XXL has a two prong plug? Would you mind sharing the s/n of the two units? I will have to check into that, I was under the impression all SuperSub's had three prong plugs.

Sure! When I get home tonight I’ll check it out.