Excellent discussion. Here’s a musical take. 
 

Why Do Tweeters Blow When Amplifiers Distort? See below:

Mike

https://sound-au.com/tweeters.htm#a6

Why Do Tweeters Blow When Amplifiers Distort? See below:
Mike

https://sound-au.com/tweeters.htm#a6

That site is normally a good source of information, but that particular section "6 Bigger Amplifiers" seems short sighted to me:

• It assumes that a hapless user, when given more power capacity, will simply crank the volume in an attempt to recreate the Maxell ad. OK, I like it loud but I’m not that stupid lol.
• It ignores the fact that music source material has decreasing energy content (amplitude) as frequency rises. This means that most of the musical energy energy is handled by woofers, not the tweeter. Speaker designers respond by designing speakers with much higher power handling in the woofer section. Quite reasonably, it’s difficult to create a tweeter with very high power handling that doesn’t adversely affect its cost and HF performance. Result: speakers can handle their rated power levels IF the spectrum content of the program material is "correct". Led Zep: OK. Lady Gaga: OK. Pink or Brown noise: OK. White noise: NOT OK. Amp clipping: NOT OK.
• An amp that’s clipping on a high amplitude low frequency wave form will create a squared waveform that suddenly now carries a LOT of high frequency energy. This HF content was NOT in the source material, but it’s now going right into the tweeter - which was not designed to handle such high peak levels of energy! Its amplitude is proportional to the LF waveform (very high amplitude - the max allowable by the amp's rail voltage) that’s being clipped, which is way higher than you’d see HF content in nature. That’s why it sounds SO BAD and kills tweeters.

When the builder, who is from Italy, came over to the states, I got to talking to him and I asked him about the output power of my amp.  I got such a look of disdain from him; clearly I did not deserve that amp if I concerned myself with such irrelevant and trivial matters.  He thought about it a bit himself and took a guess (I would not expect him to have actually measured it, how it sounds is the only consideration)

@larryi I get that a designer might think of his product like a fine wine; or at least, convey that POV to a customer. But the idea that they had not measured the output power is a stretch! This is because you cannot know if you have optimized the output circuit without at least measuring the power!

@mulveling. I think this addresses what you wrote in your post.

Danger! Danger, Will Robinson! See below:

Mike

https://www.cieri.net/Documenti/JBL/Technical%20Notes/JBL%20Technical%20Note%20-%20Danger,%20Low