Front and delayed rear subs design

[xplod1236]

I honestly have no idea what it's called or even how to search for it. It was a design that had subs in the front and in the rear. The rear subs were run out of phase (IIRC) and delayed by the time it takes the wave from the front subs to get to the rear ones. Could anyone provide any more info about this?

 

[Speedskater]

Check out the "Double Bass Array" (DBA) discussions over at the AVS forum.
below will has the links:

http://forum.studiotips.com/viewtopic.php?t=3147

 

[xplod1236]

I think that's the concept I was looking for. Thank you very much.