Quoted from Gogojohnnyquack:http://www.pinnovators.com/catalog/product_info.php?products_id=38&osCsid=3j5lhhfuu2lc22iclrvcquo6m4
I've got Pinnovators adaptors on all my pins, with their PinSMX 4-to-1 mixer connecting them all to one sub. Works great. In my newer Stern (TWD) where I can't get the audio cable out of the main cabinet I run it up out of the top of the back box through the topper wiring hole.
http://www.pinnovators.com/catalog/product_info.php?products_id=58
Updated link (new site as of 11/1): https://pinnovators.myshopify.com/products/pinsmx-passive-subwoofer-mixer?_pos=1&_sid=651baecd6&_ss=r
Use this code YDH69A53QCH8 at checkout for for 5% off your first order at our new site. Valid until 2:00 pm EST Nov 6.