I decided to upgrade my amplifier this weekend from the 4250 to the 6500. My 4250 was only "pushing" 350 x 1 @ 2 ohms Now with my 6500 I am pushing exactly 623 watts x 1 @ 2 ohm and 775-watt peak @ 2 ohms on a 12.5 volt rating.I can really feel the bass in my chest as if someone was pounding the back of my driver seat with sledgehammer. (now that's bass)I can't go any higher on the wattage with out blowing my 12's. Any higher will required Thunder8000 subs which can handle 1500 watts peak.My 6500D is slightly large that the 4250D shown below:
http://www.imagestation.com/mypictures/ ... n=mtx4250d