For about two months now, I've been using a modded system.
They're originally computer speakers. I just wanted to see what people would think about what I did... ;)
Basically, I didn't want to run everything through the green board in the sub because I wanted to have the right and left speakers taking in regular output. (receiver, in my case). I disected the sub, and found that the sub could be powered all by itself, like regular subs are. I cut the cord on the right speaker (now left) so that I could connect the speaker to the receiver. There are other little wires running back and forth up the cable, and I'm not really sure what they do. The white and red were the prize.