A cool thing about 4 ohm speakers is that they will draw more current from your amp meaning that they will be producing more watts.

For example, an Outlaw 770 is rated at 200w x 7 into 8 ohms and 300w x7 into 4 ohms. Because I have all 4 ohm speakers, i'm running at 300 watts per channel instead of the wimpier 200wpc.

-sbc