Here is a pic of one of the channels of an SDS-SRS:
5'3" tall, 185 lbs each.
When Stereo Review test them in '85 they put 1,750 watts through them before the amp blew up...
;-> I only have a paltry 180 wpc.
We used to "make" louder headphones by taking two speakers, and using the floor as a third side, make a triangle to stick ones head inside and "crank it up".
I inadvertantly tested my hearing at home using a home written basic program to test my PC speaker. I wasn't using microphones to check the frequency rolloff of a PC speaker and thought that it cutoff a little early. As I was demonstrating this "fact" to one of my kids, he pointed out that he could easily hear the speaker at much higher frequencies than I could.
Well, it was good while it lasted. ;-)