I have a couple of PSW10 subs that I alligator clip to my pins through the cabinet speaker. Sometimes I get a feedback noise on certain pins even when sub is powered off but when using a Sony SAW2500 I have never had this issue on any pin. Any ideas on what would cause this?

So you hook either the left or right channel wires of the converter to the cabinet speaker on this? I could give it a try to see if it helps.

Thanks to all the replies and very helpful info. Just weird that it only does it on certain pins and not them all.

I have had it happen to pins on different circuits. Never had any problem with my Sony subs either just the Polk ones.

So found out this only happens when I have the left and the right line level inputs hooked up. If I just hook up either the left or the right to just one pin the noise goes away.

So my solution was to have a line level converter to an RCA input for one pin and just speaker wire input on either left or right input for the other pin. I may not even need the line level converter just each hooked up on a different input.