Hi i just got 2 MBquartz amps. RAA2400, RAA4200. My main problem right now is with my sub or amps. I have 2 X12D4 PG speakers in a box. I notice my amps gets very hot and now my bass fades after 30 min. I dont know what is the problem can you tell me if it is my sub or my amp that i need to change. X12D4 is at 500rms and 1000 max. My amp is 4@ohm 200w.