Push-Pull sub designs ?

I was over at a friend's house recently and was quite impressed with his old M&K sub. It has 2 12" drivers which are both active in what they call a "push-pull" configuration. This to me would seem exactly the same as "out of phase" with one driver going in while the other moves out.

How does a push-pull config work ? Wouldn't you get less bass with the cancellation of them working out of phase ?

It obviously works very well but I can't fathom how push-pull adds bass and doesn't reduce it...


jblnut

Push Pull systems are wired one woofer in phase the other is wired out of phase! The woofer firing into the room is wired in phase, and the woofer facing the inside of the cabinet is wired out of phase. So actually it is firing into the room, both cones are actually firing into the room! One woofer pushes, the other one pulls!

They say this configuration reduces distortion and cancels out non linearities. I have listened to a few PP designs and they do sound good. TAD makes PP speaker systems, and the bass does sound very clean, and these designs seem to put out good SPL.

It looks strange, it seems to be strange, but it does work!