the amp is a kenwood 600 watt max amp and the subs are 2 12 in MTX 4000.... so i'd only been running the subs at about 1/2 power. i haven't had any trouble before now with the subs or amp. when my music is turned on they kinda just make a faint farting noise when they should hit. They barely move at all and fail to do anything at all most of the time they should hit. Its almost like they are struggling... thanks for any help