I wanted some professional sounding subs to really get that big fat bass for live events, both for bands and club music.
Before, i used 4 single 18" subs, wich did a pretty good job. But these bad boys really do the trick. I can easily turn up kickdrums way loud, with headroom, and sub-sonic rumble down to about 25hz outside! Both me and the audience is very very happy.
The crossover stops at 100hz, i think «infrasub»-mode pulls the crossover down to 80hz.