One BTL 18" *PSI Recone* blow through box help?

[Krazykid122]

My explorer took a dump on me, i stripped it of everything and bought me a 93 ranger single cab step side bed, nothing to big. I was wanting to do a Blow Through with my BTL 18, the kicker 12 in front of my center console isn't cutting it. I was wanting to do a 4th order, but i don't know much on them and what little research i have done if there not built right there shit, and they take up more space, plus im not box expert, im happy with a basic ported box if it gets loud. The bed is 18" tall iirc but if it sticks up a little that's fine im going to bolt it down and get it bed lined.

Could someone help me with a box design?

Its a Fi BTL 18" reconed to D1s, 3k RMS from PSI, if possible id like it tuned around the 32-34 hz range.

EDIT- If a 4th order is possible for me to build decent PSI said 3ft sealed and 6 ft ported @ 36Hz is what they recommend.

BED DIMENSIONS

- 43 inches wheel well to wheel well

- The bed is 16 inches tall but i was wanting to keep the hole below 14" with the box having an external port going into the cab so the whole is smaller and the box can be bigger farther back for the size of the 18" plus wood.

- the wheel wells end about 4 ft from the front of the bed then there is about 2 ft until the tailgate, id like to have a little room in the back for batteries/handheld toolboxes.