In a recent post of yours regarding the audibility of phase, you mentioned that you were going to do an article on push-pull subwoofers. Did you ever get around to this? They interest me too, and having the cones directly coupled and wired out of phase, reducing even order distortion is very interesting to me. Anyway, if you get the time I'd love to see a write up on this!

Check out the following links:

• EAW

• M&K Sound

• Whisper

Each of these are commercial sites, but they show implementations of push-pull bass configurations. Personally, I find the exposed basket of the M&K speaker to be a little bit ugly, and I think the π cornerhorn would be a perfect solution because the exposed basket would be hidden. The π cornerhorn would also serve to act as a summation chamber in the area between the baffle and corner apex. This may prove to be an attractive loudspeaker configuration.

Adam