Is there a website where they are selling these?

Mine has the same problem with the speaker wire inputs. Speaker wire to RCA works perfect.

I just wire regular old speaker wire from the tabs on the cabinet speaker (using alligator clips) to the speaker inputs on the back of the powered subwoofer. Have done it for Sterns, Segas, DE, JJP, basically every game I have ever had. Works perfect EVERY TIME, is simple and easy to reverse. I just make sure + goes to + and - goes to -. People go in with RCA cables, wire directly to soundboards, utilize pinnovators etc etc. Unnecessary. I tap two machines to each powered subwoofer, one machine for each input.