OK... I stand corrected. I just searched and found that Speakerlab does in fact exist again. But the kits they sell now are a hollow shell of the totally butt-kickin' stuff they used to sell.
The classic ever, was the Speakerlab Super Seven. A towering monolith of power and beer-bottle-shattering madness. That was even before you turned it up to eleven. :-)
As a starving college student all I could afford were those Fours that you saw today. Then I got my mom's Nine's and between the two pairs they might be close to what a Super Seven can do.
But those Fours have been documented to crack and remove drywall from the walls of dorm rooms. Honest. We're talking real structural damage. It was a thing to behold. There's a really funky thing that happens when a standing wave occurs in a square room... and the walls start to breathe in and out... and BAM! Stuff breaks.
Ahhh... memories. :-)
Dunno about speakers, but one windstorm came through downtown Detroit that busted out big windows. I was in an inner office of the Ren Cen, and noticed they were clearing people out of offices with windows. I ducked into one empty office, and heard this "wubba-wubba-wubba" sound. Then I noticed the reflection of the room lights in the 10x10 foot windows. The windows had an excursion of about two inches in both directions. A little voice inside me said, "neat subwoofers, but I don't want to be around when they let loose".
I beat a hasty retreat, and found out later that the windows did let go, but blew out, rather than in, the building. By then, they had cleared all pedestrian traffic around the base of the building.
Still getting caught up here, but there's a warning of one-inch hail to the south of us, and a tornado warning to the west. And I head off for the afternoon shift shortly.