Hello. I'm new to this forum and I'm looking for some suggestions with my subwoofer set-up I just recently completed, as I do not believe I'm getting the best sound possible out of what I have. I can provide some basic specs on all of the components to the system for starters and can provide more if needed. I'm not new to the car stereo world but there's a lot for me to learn still which is why I've turned to this forum. So here's the components: 2 Infinity Kappa Perfect DVQ10s; 1 Kicker zxs1500.1 amp; Kicker PK4 wiring kit; Fierce Audio build-a-box dual 10" enclosure; and a Pioneer DEH-4800mp head-unit that still has some life to it. The basic specs: The subs are rated at 400w rms at 4ohms and are dual-voice coil with the medium-sized Q-inserts installed; the amp is 1500w rms at 2ohms, 750w rms at 4ohms; the build-a-box is .75ft^3 per chamber. The "issue": Based upon what I've read on these subs I'm not entirely happy with the output. I essentially have them designed to "punch" for rock and metal music and I have not experienced that to my desired taste. I've heard my roommates 2 Type S subs with a 500w amp hit frequencies in songs much harder than my set-up. Like I said I'm not new and I did as much research as I could to acquire a high quality sound, but I think I did something wrong with this set-up. I'm thinking possibly the wiring kit, the box or even the wiring which was done professionally. They informed me the wiring was done in parallel. Does anyone have any corrections I should make to the set-up? Anything would help. Like I said I can provide more information to any or all of the components as needed. Thanks in advance.