Amp or Subwoofer causing Hum?

Yes, if you want to connect the sub speaker level just connect a wire from one of the sub amps screws to the Rogue's phono ground lug. Simpler method is as suggested from the Rogues fixed outputs to the sub via SE cable pair. 

"Yogi boy if I use the fixed section and I adjust the volume up or down on the amp will it adjust the sub volume to maintain the balance ?" Yes it will! You should use a pair of ICs from the preamp outs to the input of the subwoofer! Does that make sense to you?

Yogi boy if I use the fixed section and I adjust the volume up or down on the amp will it adjust the sub volume to maintain the balance ? I used the splitter to go into left and right of the amp. I use one cable from the sub with a splitter to the amp so both left and right are connected. Is think not good? 

Why are you using a y splitter? Why are you using the variable outputs on the Rogue? You should use the fixed outputs on the Rogue straight to the inputs on the sub and adjust the volume on the sub!

Thank you! 

I’m hooking the cable via variable out Not to a speaker terminal. If I wanted to do what has been suggested would a wire from the amp phono ground work but to what alternate ground? 

If you are connecting an RSL subwoofer via it's speaker level inputs then the negative input terminal on the RSL is not a ground as it's a Class D amp.  The way to resolve the hum is to connect a piece of wire from one of the screws on the amp to an alternative ground point.  Those instructions for hook up are directly from Joe Rogers. When I had the same issue with a pair of Speedwoofers I just stripped a length of zip cord but any wire should work.