SVS's thing isn't extreme loudness, it is deep, clean bass. The SVS subs have a lot of deep bass output, and it has very low distortion. It you want something that is simply louder than your Klipsch, there are better choices. For example,
here is a $800 sub that will get many times louder than the SVS 12" subs. It doesn't really dig deep, but boy howdy will it get loud.