I have been looking alot into the FI Subs and finally going to decide to buy my first FI Sub. I decided to go with the SP4 15. My first question is I need help with ideas/suggestions of my box. Now here's what I'm dealing with: 04 Cavalier Trunk Build sealed w/ sub and port forward. 2 XS D3100 in rear Taramps HD 6500 (Will keep gain down, want to do roughly 4k Watts to sub or suggestion?) Stock Alt (Don't plan to upgrade) Daily Driver, not SPL or competeting, just Pleasure to be LOUD I play All types of music from Decaf Slowed to Christian to Rock. I want to play to the mid 20s and up to the mid 50s decent, but of course tuning area gets best, but still some output 40-55hz range... Dual 2 SP4 15, wired down to 1 ohm. I want to get the most out of the Sub for Fun not competeting that will make the Sub Shine, not for DB drag or anything. So, What is suggestion as far as the Box or any other explanations from your experiences?