As of right now I am using a single JL 13W1V2 in a ported box to JL specs (2.6 cu ft @ 26 hz). The only reason I am using this sub is because i used to have a single cab truck and two of these were the largest subs I could find that fit behind the seats. Since then I have gotten rid of the truck and now have a CRV. Both of these in the sealed boxes they were originally in were ridiculously loud and assy sounding in the CRV so I built the ported box for the one. Honestly I could hardly tell any difference between it being in the 1.5 cu ft sealed box and the ported one. The sub is loud as hell at around 55hz and gets quieter as it goes lower. Is it because I **** at box building? It's hooked up to an Eclipse 8443 h/u and an Alpine MRD-M501 V12 amp (the one year they didn't ****) so the issue isn't there. Anyway I am looking into getting something new as I am very unhappy with the current state of things and want something that is going to have no problem playing as loud at 25hz as it does at 55. I appreciate any suggestions.