Mine has a hum all the time and my amp chassis doesn't have a ground on it. What to do? Called Sumiko once and they told me to unscrew one of the screws on my amp to connect. Called the amp manufacturer who said that would immediately void my warranty.
REL subwoofer hum
I own a REL stadium III, and have owned it for some time now. Just recently I noticed that it will produce an audible (although low level) hum when I turn my system’s amplifier off. I have the Stadium hooked up in the recommended manner: I have it hooked up with the neutrik cable to the Speaker B terminals of my amplifier. Speaker A terminals are occupied by my Sonus Faber concertos. When both sets of speaker terminals are on, the sub is quiet. When I turn off the B speaker terminals, or turn off the amp altogether, a low level Hum is output by the REL. I have not noticed this hum before and believe it to be a new occurrence. However, I guess it could be a ground hum. My main amplifier, and the REL are plugged into two different outlets, both outlets have quality AC filters/surge protectors, and I use the stock power cords for the amp and REL. Should I alter my hookup method? Would better power cables help? I really don’t want to have the REL serviced as, I’m sure you know, it weighs 110 pounds, and I don’t want to have to move it. If it is a so-called "ground hum", how do I alleviate it?