I've got several Polk subs hooked up to two games each. I didn't need anything special. I just took two 6-8' lengths of wire and connected one pin to the sub via alligator clips on the bottom board speaker and inserting the other end into the left or right sub input. Then hooking up a second game in exactly the same way using whichever input is now available - either left or right. I've played both pins simultaneously with no problems. The speaker appears able to handle it fine.

I use psw 10 and have them hooked up.to 2 machines each. Sound great even when both machines are played at the same time. No special hook ups-just alligator clips to l and r inputs. If you stop to think about it, in a stereo hook.up, l & r inputs are connected and play fine so why wouldnt 2 pins?

Anything will work. The clips are to connect to your bottom speaker easily. You could also solder the wires if you dont have clips. On the Polk side, the bare wires just slide into.the slots provided.
It's not all that exacting a science!