I am looking to upgrade my current stereo. I currently have two 15" '03 L7's in a 2000 grand am. These subs are way too big and sound like sh*t in such a small trunk. I am going to get one JL 13w7. I am big on sql but like my music loud (around 140 db). Should I use a sealed box or ported box? I want the lowest bass extension on the sub as possible because I like deep bass. I know a ported box will be louder but a sealed one sounds cleaner and I don't need a subsonic filter with it. Any suggestions would be appreciated.