Thanks for the email copy. I still stand by that advice- my answers above on Power are more explicit.
And Pete is not a wild man- he's just being Pete. There can only be one.
We all use up a lot more power, very quickly unfortunately, when we finally decide to play it LOUD, listening 15+ feet away.
If we just start to clip any amp, often we don't notice that at first, in some speakers because they are not clear (agile) enough. And in the Europas, in my opinion, this is because they don't "hold onto" an amp's clipping distortion- the actual onset of clipping is not magnified by them (its duration extended).
Any brief hardness/harshness from the amp remains brief because A) it does not trigger some particular cone resonance, etc. and B) because the time-coherent design keeps the packet of energy concise, if you will.
So then, if you don't hear what you think is clipping, it seems ok to take it up another full notch, to put the hammer down, because we say it's ok. But clipping any amp, or peak power levels exceeding 80W into 8 Ohms on compressed rock, means the tweeter will eventually go. Just like racing a sports car- new tires every race. About $30 for a re-tread here, per cab.
One can hear the clipping of course, if you know the recording and then take the loudness up very, very, very, very slowly, until you hear the amp just start to haze the image, then hear compress the depth, then finally rat-out the leading edges ever so slightly, but only on just one particular 'yelp' from the voice... sounds like a brief mic or mic-preamp overload (like an old doo-wop recording), except.. it goes away with a few dB decrease in the volume.
This is not the speaker distorting, because speakers, of any kind, seldom "clip" harshly- they just gradually compress the dynamics, then finally hard-limit (clip) in the woofer's stroke (or fuzz out at large excursions), or the tweeter finally blows up.
The gradual-compression effects in speakers are just that- gradual. They do not "go away" because you reduced that slowly-increased loudness by 3dB (half the power). Nor do you hear THE problem of image diffuseness, hardness on the voice, etc "come back" because you went back up by just one dB.
Hope I said that clearly- sorry if you have to re-read that. It's a linearity issue. Speakers and amps have different ways of leaving their linear behaviour regions. It's why an amp designer can tell the size of a power supply on just about any speaker at only modest SPLs. The departure from linearity he has trained himself to hear from a transformer is different that what speakers "always" do to the sound. He's also heard a lot of speakers.
So you miss the fact that the amp is starting to clip on rock, or loud R&B, etc. Because you don't care, because you don't know the recording that well yet. So you crank it on up one more full notch and leave it there- then the tweeters eventually die in the Europas, because you are near 100dB AVERAGE levels at 8 feet away. Which means pounding loud at that distance, yet merely "pretty darned loud" at fifteen feet, especially if the room is not a lively one.
It is always instructive to borrow a high-horsepower amplifier, even if you know it will be rougher-sounding than what you have, just so you know what happens from having the large power-supply capacity available on a moment's notice.
The Europas can handle peaks, briefly, to 120W into 8 Ohms, midband, like a snare drum whack, which at 8 feet away, is about twice as loud as most people think as being LOUD. Close to "my friends up on stage at 20 feet away- can't hear you right now!" loud.
Which in some societies is considered fun.
Best,
Roy