I installed a pinsound board and the stereo wiring in a wpc89 machine that was already hooked up to an external subwoofer. When I turned the machine on, I got no sound from the cabinet subwoofer nor from the external subwoofer. I did get sound from the back box speakers. Note that I have pinball pro speakers in the machine.
Once I disconnected the speaker wires from the cabinet subwoofer that were running to the external sub, the sound came through the cabinet subwoofer.
Does anyone know why this would happen? I’d like to utilize the external subwoofer if possible. Thanks for any advice.

I will look into that. Just need to locate the proper wiring. Thank you

I did install speaker wiring with RCA jacks and it works great. Thanks