been running my 2 fi 12's at 2 ohms.
first set up i was giveing them 15oow rms at 2ohm, in a ported box, box was 3.5 cu ft ported tuned to 32 hz, did 139.9db in a trunk car.
now i am giving them 2000w rms at 2ohm in a 4.5 cu ft ported tuned to 39 hz in my acura integra doing 146+db
vid's and more info in my sig...