Got the box built today, sub has been in the trunk for about 15-20 minutes.. only problem is that it doesn't seem loud at all.. Not that was expecting extreme loudness, but i was deffinitely expecting more!. Sub: JL 13w1 4ohm edition, Amp: JL e1200. Amp was installed professionally.
Not sure if i have the gain set properly, i messed around but it didn't seem to do anything. One big problem is that my rear speakers are so loud you can barely tell...
edit: just drove around some... Deffinitely gets louder. i hate to say it buti may be getting a headache

Tommorow im goin gto see if i can snag my dad's 18v drill and get those stupid fuckin speaker adapters ut so i can use my good speakers up front!