Alright I have a kicker zx750.1 amp that was running a Legacy 15" 1200watt sub however while driving today they turned off. I stopped to take a look and i noticed my amp would power on then just as the sub would begin to pound the amp would power off and the protection light would turn on. Now my question is whats going on I checked all connections/fuses and they are all fine ground is fine as well have I blown my sub as when i disconnect it the amp stays powered on. Also if I have I have two mtx 12" subs sitting around and if I connect both to my amp (its a mono amp) will that work?

In all likelyhood the subwoofers voice coil is out of alignment and is rubbing the pole piece. subs toast. You can hook up the MTX"s provided you wire them up to a 2ohm load.