i have a alpine 4-channel mrv f345 (rated 75rms @ 4-ohms )and first of all i cant even turn the volume all the way up bcuz it shuts off. if i play my music with my volume set to say 18 it gets flippin hot after i few minutes. the music output at that volume is pathetic...its like my headunit can go louder without it....now for my 4 speakers they are all 4-ohms and the amp is wired @ 4-ohms. 4-gauge power and ground. 12 gauge speaker wire. Now, the big question what the hell did i do wrong?, bcuz i jus connected a 600watt fusion 4-channel amp (also rated 75rms @ 4-ohms )(Fusion Encounter EN-AM60040) and while i was able to turn the volume basically all the way up my happiness was short lived as the amp again go extremely hot and shut off. Fusion amp was brand new by the way....Now i don't know if this means anything but the magnet from the speakers mounted in my door panel are touching the door frame as the magnet is kinda big. any answers, suggestions, comments would be greatly appreciated.