This is my review of the pioneer premier 3004spl's........

amp: (1) orion 1200d @1 ohm (roughly 600ish rms to each sub, UNDERPOWERED)
box: 1.9 cubes @35Hz apiece w/ 24" sq. port area
vehicle: 97 chevy ex. cab with back seat taken out
misc. settings: gain= about 1/2 way up, bass settings on deck: +1 (-6 to +6 range)
zero sound deadening as of now, but some is on the way........

review:

I used to have the 2000spl's in a crappy sealed prefab box from BB, in a 90 camaro, with the box facing the hatch, and they slammed, they were off a hifonics bx 1500d and it was a great system for the money IMO...the 3004spl's absolutely hurt!!!for the first 2 days i had them i had to watch the volume or i'd get headaches. I bought these subs for $200 from a buddy of mine who pushed them with my old bx1500d in a probox and the slammed as well, i bought them and put them in a box made to fit their specs a little better, and im so happy with the results, i highly recommend these subs to anyone who loves gut crunching, head rattling bass and doesn't wanna break the bank....For anyone who wants to know, i have my subs and ports facing up......Hope this helps and see ya on the forum!!