um..... correction I talked to the head tech at maxxisonics. Don't remember the guys name but the same boards they use for the bxi line they use in the crunch amps. and as long has you have 14.1 volts or higher it will do what its rated at. but think of this. if you are running single 4 ohm subs and your running say 500 rms x2 at 4 ohms. realize this, you will have impeadence rise. so you may be seeing something like 4.6 ohms and will see effictively like 380 to 400 watts rms. and if you are unable to hold a min of 14.1 volts at full tilt you will drop even more. say you drop 14.1 to 13.7 you loose 18% so at 1000 rms x .18 = you will lose 180 watts so you will only get 820 watts rms max so you will only see about 250 to 300 watts rms at most! for the price you will get good power and decent sq. Not a show winner for sq but good enough for most DD.