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.... 


Try using a cheater power plug on the sub. 

I had the same problem with my Sub Utopia. 

Could also try one on the amp to see. 

In addition to the other responses, if you’re bridging the amp, it acts like a differentially balanced amp so you can’t connect up the black wire to the black post as it’s not a ground but rather an additional hot supply. You’ll need to ground to the chassis or some other secondary ground.