I think the PB16-Ultra is as about as far as SVS will go for a mega-sub. Keep in mind that SVS deals all over the world, and the logistics of manufacturing a 200 lbs+ behemoth is expensive and complicated. Anyway, a better approach to subwoofage is multiple small subs, not one or two gigantic subs. Monster subs aren't all that great, unless you only have one location to put a sub so you might as well make it the most powerful sub that you can afford.