I have the lower version 602sx and it will push around 3,600rms @ 1ohm bridged or 2x 1,200 @ 1ohm stereo. very powerful amps bt you have to jump the voltage up a bit in most cases to get the most power from them, there are mods you can do internally to help achieve this i've heard/read. if you're talking about the Ma Audio HK4000D then it's a....well hell...........here's the specs i could dig up real quick. I have never had a single issue or problem with any of the 5-7 i've had, but everyone has their opinion.
4000W Digital Class X Competition Mono Block Amplifier
RMS Power @ 14.4V
1800W x 1 @ 4 Ohm
3600W x 1 @ 2 Ohm
RMS Power @ 17.0V
2000W @ 4 Ohm
4000W @ 2 Ohm
if you google the amp you should be able to find more info on the "mod"
Owned almost every bigger ma audio amp, and they are good amps, i like them, hard to beat the power for the price, and yes they do **** some power, but one HC2400 in the rear and 1/0 gauge you will be fine!! Good amps!