One of the subwoofers mentioned is a coneless, fan-driven rotary system that gets frequencies as low as 5 Hz! Instructions include mounting in a basement or attic. Pricing? Consider about $25,000. Ummm, yeah.
The second speaker, a 60 inch subwoofer, made the vehicle housing it balloon in & out a couple of times during testing. That puts those wannabe gangbangers in my neighborhood to shame!