To all my friends who care for this kind of thing I stumbled upon this article the other day

http://www.digitalgrabber.com/audio/the_60_inch_subwoofer.html

Its about a 60 inch subwoofer, it needs to be amplified with 1 MegaWatt of power. It can produce 188dB in a closed vehicle and blows the doors off normal cars. It’s air displacement is equal to the displacement of 160 10inch woofers to give you an idea of the sheer force of it.

Pretty cool stuff.