you have a few possible problems and solutions
one run an extension cord plugged into where the gear is also plugged in
this will tell you if you have a ground loop.
alo make sure you are using all three wires from the speakon
REL Sub Hum
Hi Folks, looking to see what the issue could be. I'm hearing a substantially loud hum coming from the REL T5/I sub when connected to the Parasound A23 power amp. The other two amps have no issues... what is a power amp would cause this issue?
REL subwoofer is connecting using speakon cable... I have not tried LFE/.1 to see if the issue persists....