i am going to get my uncles kicker l7 and try out with the amp, if it pushes it good, then mx sub sucks and if it does not push it, it's the amp that does not work.
i just found out the problem, some thing is wrong with the amplifier.I connected my kicker 1250 sx and it turned on the mx12 with know problem and it's loud.****, I hope they can fix this amplifier, it's like a 3000 amplifier.