I have a single Deathbox in mine. Port pointed to the rear

http://www.decware.com/newsite/dbk10.htm

The insert is intended to slide to tune the box for the speaker you put in it. Yes, its an adjustable 4th order

Some of you at the first Mohegan Sun, or the BBQ at Bantan's place heard(felt) it play.

2 of these would be no joke.

John C.