System Help PLZ PLZ

Ok i finally wired up my new system, i have a dual deck, a kenwood 2 channel 920watt amp, and two 12" audiobahn subs bridged, 400rms watts each i think. Anyway the problem is, when i turn up the volume the subs cut out sumtimes and sumtimes i blow the amp fuse and i have to replace it. So i was just wondering wat the problem could be. So what will I need to buy to be able to turn up the volume without the fuse blowin or the amp getting hot?

do you have a fuse by the battery on your power wire thats blowing?
do you even have a fuse on the power wire?

it's likely that during peak power, your briged speakers (i'm assuming 4ohm each) are occasionally inducing less resistance at the peaks than what the amp can handle, which will result in too much current being drawn at those peaks & blown fuses. eventually it'll mean blown driver transistors inside said amp. driving speakers in bridged mode IS the most efficent way to do it, & results in cleaner & more power..... but - not all 4 ohm speakers work the same. like i just got done explaining in another post, speakers don't actually have 4 ohms at the coil when measured with an ohm meter - they are rated because of the amount of total power it's consuming within a given frequency range -- it'd take too long for me to explain all over again, but to sum it up, some speakers can have a particular frequency that when they are operated at, will lose much of their induced resistance. the end result of the affect is sudden high current usage (and sometimes speaker and/or amp damage). though it will reduce the effective power somewhat, putting a speaker on each channel of the amp & running it in stereo mode instead of mono will cure your fuse popping problem & keep it from cutting out & damaging your speakers or amp. the only other real solution is to give another brand/model of speakers with similar ratings a shot to see if they also have this kind of cumulative impedence loss at a given frequency.