not quite all the way to 25, they meet up at 28hz or so, but yeah. The tempest has a 1db advantage from 40hz and up and maintains some sort of advantage to 28. Even a the bottom of my graph at 20hz it's only finally behind by .3db's. The tempests f3 is also 2hz lower. The tempest will also be right at xmax with 1000 watts applied at 20hz so it's a good match in that box. To get xmax out of the sdx is 3.5 cubes takes 1300 watts.