CEA rated means 4 ohm load on 14.4 volts @ 1% THD. So no clippin on 4 ohms. Try and use a DD-1 to set your gains or an o-scope and you won't have a problem.
If you have voltage drop you won't do rated either though.
If it's an Alpine M-1000 then that's a great amp, however under clipping or voltage drop it heats up FAST... I pounded my Alpine M-1000 for six months and had it runnin for hours upon hours almost every night all summer lol, so they definetly last.