Never hook up too many subs, this will draw too many amps and could cause the power supply section to fail, usually a maximum of 3 subwoofers on a monoblock no matter the wattage! Always match the subwoofer/subwoofers impedance to the minimum impedance of the amplifier! I just repaired a cpt1 1500 and for the power supply all of the joints were failing and it had led to some shorted mosfets and burnt gate resistor, there was very little heatsink compound, I have encountered this on a api hifonics zeus as well, that was made before maxxsonics bought the company! I have bought many failed amps that all suffer the same failed power supply mosfets! Usually excessive heat can either be caused by lack of air, too much current draw which puts strain on the mosfets or too low an impedance for the wired setup which puts strain on the output transistors! Another thing that can cause it is poor connections internally! What ever happened to CE or CEA compliant Technologies? People are putting money into peoples pockets that don't even want to produce quality products, but want to sell them forgetting the Audiophile Ideology! The same people who overrate all their amplifiers, one example would be Lanzar MXA224, it says 1000 watts max but on the label it says rms power 50x2!

Be sure the amp is located in a well ventilated area as heat build up can cause a safety override to cut power once temp. reaches a certain point. amps do generate heat though so if you dont think its cutting out due to excessive heat building up, i'd definitely get a power capacitor to help keep a steady supply of electrical energy available for instances where the bass hits really hard or for prolonged periods of time. if you have a power cap already make sure it doesnt need to be upgraded to function properly. hope this helps!