Back in 2018 I blew up 4 different speakers trying to get a profile from a Silvertone twin 12. Not a super powerful amp but the test tones are LOUD. I got the lower volume clean profiles just fine but when I went above 6 on the volume, KABOOM!! (actually no real kaboom they just stop working). All the speakers I used (Weber, Celestion, Tone Tubby) were newer and rated much higher than the Silvertone head. I'm sure it was down to operator error as in all my endeavors that go wrong but it stopped me from profiling any of my vintage original combos.
Just out of curiosity: where those speakers rated at a lower wattage than the amp's (maximum) output?