I use a pair of Carvin 12's most of the time for outside patio jobs of around 400 all the time. Often, I use 4 12's, but thats because I have people front, back and both sides of the bandstand.
The 12's have plenty of bottom. With two Yamaha 200 watt heads, there is more than enough volume, but that's because I'm playing dinner music.
Russ