Why? Why does it need rated power plus 400watts per driver? No such thing as under powering being a bad thing. Consider the drivers being overkill for the amp, and not the drivers being under powered... I should have worded that differently, I know it doesn't need that much. I ran a single SA-12 off 400w & it got loud enough for my liking. I'm sure someone with more knowledge will chime in, but here's my .02 .............. A single SA-12 with 1,000w & a proper size ported box would be louder & more effecient than two SA-12's with 500w each & restraints on box size. And with one you don't have to run it at exactly 1,000w, the gain can be cut down some & leave plenty of headroom. With a pair of SA-12's you're really gonna be pushing a SAZ-1000. Plus, it's gonna be $200 cheaper. You’re doubling motor force and cone area. Theoretically it should be louder than 1 12" on 1K watts. Plus he could always add another SAZ-1000D and strap them to the pair or upgrade to either a SAZ-2500D or bigger.