single 18 4th order help

[lilwillywilly]

Trying to design a 4th order for a single crossfire xs v2 18. Box is gonna go in a jeep cherokee.

I have read quite a bit on 4th orders, always wanted to build one. And thus far I think I understand them pretty well, I got a few guidelines to go off of anyway.

Box will be used for a daily setupn with occasional comp or demo. Rap and dubstep will be the music of choice.

Here is my issue. Lol. I want to start with the sealed side, sub will be inverted. How many cubic feet should I shoot for on the sealed side.

I can figure the ported out from there.

Thanks in advance for any help guys.