When I tested my first WOPL 700 (640 WPC), I turned up the amplifier full blast (input was a Hafler CD player via the venerable PL 2000 preamp) and ran out of the living room. It was too loud even standing in the garage with the garage door open. I walked down to the end of the driveway, about 100 feet, and the sound of Humble Pie singing "I Don't Need No Doctor" (which contains some nice musical dynamics) was as clear as a bell, even the cymbals.
The JBL 15" 2226 woofers and the 2426J high frequency horns were handing the 1280 peak watts pretty well. Anyway, because the amp was in the walnut enclosure, it got hot before the song was over (about 7 minutes) and the thermal switches de-powered the amplifier.
As I was checking the ambient heat coming off the heatsink fins, the amp had cooled off enough to allow the thermal switches to reset. When the amp came back on at the climax of the CD track, the speakers erupted, and I jumped about a foot straight up.
There was no damage to the speakers or the WOPL amplifier, thank goodness. This is how I became a believer in WOPL... What other amp can have the power cord yanked out of the socket and then plugged back in at full tilt, Mach 10?