Pictured is the PinWoofer WPC 12V Power Cable. Routes from the power jack on the amplifier to the backbox Driver Board.
The WPC Driver Board can be seen within the yellow rectangle located near the lower center of the backbox.
Shown within the yellow rectangle is header J116.
Plug the 4-pin connector into this location. Note the orientation of 12V power (red) and ground (black).
Shown in the yellow oval, plug the opposite end of the cable into the Amplifier module.
Pinwoofer TM - ID § 48-501