Loudest speaker on earth
Wyle Laboratories is the proud owner of the loudest speaker on earth, the WAS-3000. It was built back in 1967 and remains, as far as anyone knows, the most powerful loudspeaker ever built, able to generate sound pressure levels up to 165 dB (Jets and gunshots can hit 140 dB) with just a single modulator. They are probably building several for Hotblack Desiato:
The Hitch Hiker’s Guide to the Galaxy notes that Disaster Area, a plutonium rock band from the Gagrakacka Mind Zones, are generally held to be not only the loudest rock band in the Galaxy, but in fact the loudest noise of any kind at all. Regular concert-goers judge that the best sound balance is usually to be heard from within large concrete bunkers some thirty-seven miles from the stage, whilst the musicians themselves play their instruments by remote control from within a heavily insulated spaceship which stays in orbit around the planet - or more frequently around a completely different planet.
Many worlds have now banned their act altogether, sometimes for artistic reasons, but most commonly because the band’s public address system contravenes local strategic arms limitation treaties.