One 12" 1500w rms subwoofer in the right box or two 12" 1000w rms in box too small?

-I am going to power them with a Rockford Fosgate T1500-1bd amp at 1500w rms. They are an RE Audio MX 12" or two RE Audio SXX in the same size enclosure since I do not have space. So which would be louder. Thanks!Ditto what dragonbreath said. The single 12 with that much power will be quite loud (and will likely sound better than 2 12's), but if you're set on having a REALLY LOUD set-up then you may want to do some more research and see if you can find some high-power subs that operate in less airspace. But you definitely don't want to mess with the recommended airspace as you can run into all sorts of acoustical problems.