the most your probably going to get out of that amps is 450 rms thats 225 per sub. but that should run them decent. you will have to use most of your gain but like the others say leave the boost off. i looked up some kenwood amps and one is close it says 1000 watts but it is actually 170 x2 @4 ohms and 250 x2 @2 ohms or 500 x1 @4ohms bridged. unless you have a high end kenwood thats what your looking at. so if your subs are dual 2 ohm wired at 4 your not giving them much. if you have dual 2 get a mono amp or a 1 ohm stereo stable. wouldnt really recommend another kenwood either. you can get something much better for the price of them. i see alot of people on here selling good amps for good prices.
i have 2 cvr dual 2 in same kind of box, basic sealed box powered by a autotek sx2200 its 1 ohm stable and it works out decent. its plenty loud. you can try getting some pollyfill to put in the box. that might help. i lined mine with it. i like sealed boxes better as im not looking for spl as much. i like everything to sound good and like the punch of rock or whatever im listening too. one thing i have noticed about the cvr subs is they lack that punch and higher frequency bass. not impressed overall with the subs. i had two in a ported box powered by a crossfire vr401 which works out great and yea they got loud but not loud with every song only songs with mid to low frequencies and i dont like limiting my music selection. well good luck man.