DiMarzio Woofer?

What exactly do you want to know?

 

OK, here's what I know, or think I know. Billy, in his "wife" bass, used a Gibson EBO pickup mounted between the P pickup and the neck. Since he didn't know how to wire it in with the stock pickup, he ran a separate output from it. Then he had the idea of running different amp setups with the two outputs. The Billy Sheehan Sig bass features pickups that DiMarzio designed for him. They are called the Will Power Neck and Will Power middle. The Will Power Neck is a modification of the DiMarzio Model One, and is his "woofer." In the Yamaha Billy Sheehan Sig bass, there are two outputs that you can run to separate amps, or you can combine them into one output IIRC.

 

Tonally, they're extremely deep. Because they're meant to be places right by the neck, they just pick up the super deep lows. NOT good for a pickup all by itself since the have little to no highs, but they're great as a second or third pickup to add tons of depth. Great pickup.