the systems not done, but here's what i either have or will have soon
well, i have two layers of peal and seal crappy sound deadening all around(really all around everything) which isn't as good as the expensive brands but works- but the kicker is that i have a layer of 10mm mdf between the layers of peal and seal everywhere there was an opening in the sheet metal of the doors.
i also have all underhood wires upgraded to 0 gauge, new grounding strap, red top battery, 0 gauge to the rear, batcap 400, all solid gold/titanium from battery terminals to rings and distribution etc, then in my amp rack (out of site) the 0 gauge is split into 4 8 gauge and 2 4 gauge, the 4 gauge go to a batcap 400 and back, two of the 8 gauge to my 800a2 (which made 1041 watts at 14.4 on its birthsheet), one of them to my 500.2 rockford amp which powers my 3-way audiobahn carbon comp abc6003 components, and one 8 gauge to a 200s rockford amp powering 5 by 7 cerwin vegas (soon to be 6 by 9 audiobahns) for rear fill. my head unit is not yet upgraded from my pioneer dehp-4000 but it will be, my rca's are rockford fosgate and are top of the line.
my box is also extremely extremely solid and well built. my uncle and i spent about 10 hours on it and we know what we're doing. it has four coats of polyurethane on it inside and out as well as two coats of spray sound deadener and 5 lbs of polyfill on the inside.
i know i'm not pushing quite the watts that you are, but i think i have my bases covered alright. also, like i said before its 2.65 cubic feet per sub without the effect of the polyfill. i set it up for some sq rather than just spl like i said before.
would you please tell me how yours is set-up? specs of the box etc. i'm excited to hear that these subs have performed that well for someone else.