Okey Dokey Dudehttp://www.reaudio.com , and engineer a box that is appropriate to your woofer. They have an awesome box calculator there that will take the guesswork out of it. I recently double laminated MDF plys, and built a box to EXACT factory ported enclosure specs, and my customer's REMX12d2 dyno'd out at 141.39dB on 1200WattsRMS (well below spec ...recomended 1500wRMS) in a new-ish Nissan Altima. So point blank... do it right, and it will sound good(and loud). It really is worth the time and expense. JL makes an excelent woofer. REAudio makees a boutique quality woofer for cheaper. And boutique quality hardware requires buotique quality instalation, and ATTENTION TO DETAIL. I have installed PALTRY woofers in the CORRECT enclosure and they are big, bold, and loud. Ie. Kicker Comps in mondo sized 2.25cf sealed boxes and they sound awesome. Feed your mondo sized woofer correctly, and it will treat you right. Don't skimp on the small things, and the big things will behave properly.
So good luck and good sounds,
EZ Win