An excerpt from this link, and auditory description of the pictured system... "I underestimated how much physical grip this sub system now has on the construction and everything in and around it. Trust me, I’m used to sub-buzzing and rattling of doors in doorframes, windows, ceilings and all sorts of stuff lying around.. the Labsubs on their own where more than capable of shaking the room...but this is of another proportion. The addition of the 4 HS24 twins LITERALLY take it from shaking the room to tearing it apart! the ceiling is shaking so violently.. the plasterwork and paint ruptured on some seams.. that happened in a few seconds.. actually it took not more than that 1 wormhole sequence of Interstellar.. the +100Kg steel rolling shutter on the outside is rattling so violently you can hear it above the sub rumble. 2 blocks down, all doors and windows in a 50 meter radius rattled (and not a little) that effected approx. 6 neighbors… everything, even heavier stuff in my adjacent garage and the garages of the neighbors is moving and falling down…the shock came when I came back in from checking the rattling (like crazy) of the rolling shutter and saw that the picture moved completely from the screen.. it was the power cable that kept the beamer from falling of the shelf… I would say at 60% capacity…in a panic I turned the system down.. and that was the point where I heard a neighbor calling. A few seconds later 4 neighbors were outside. Previously (in my Labsub era) they could laugh with it…not anymore! This is no teenage bass-bragging, it is what actually happened.. literally in one wormhole scene…" All I can say is...wow! He almost destroyed part of his neighborhood within a 50 meter radius with infrasonic sound. You sold me on it, I gotta make one of these!