This is going in a 2012 2dr Jeep Rangler Rubicon for an SQ application. ORION of course markets the subwoofer as necessitating the use of 1" MDF for enclosure construction. After contacting a company I've used for 18yrs to procure the 1" material, I found out they didn't have any and it took the better part of a week to locate the stuff in another state.
I picked up the sheet and got busy on what you see below. It was designed by PWK to yield a relatively flat response at the headrest, over a pretty wide bandwidth. This target response necessitated what you see here, an aperiodically-coupled bass reflex. It was easy enough to build, once the weather cleared back up. It was finished this afternoon and should be packaged, insured and shipped tomorrow.