Can a power amp have too much power, risking damage to a speaker?

A general rule of thumb we see in service of loudspeakers 

too much power sent to a speaker cooks woofers (from being too loud, beyond the dynamics of the speaker)

underpowered usually cooks tweeters as the amp runs out of power and begins clipping ( clipped output = square waves = impossible for a speaker to follow a square wave precisely so it overheats trying to )

Brad

Not a good match.  Don’t do it. 

I spoke to a manufacturer who said that excess power is a big threat to speakers more so than high frequency components of distortion burning out drivers.  I’ve seen too many examples of accidents with high powered amps sending damaging pulses to speakers (someone accidentally pulling an interconnect, a power failure where flickering power results in a loud thump, etc.).  I don’t get why people play their systems so loudly that they would burn out drivers from distortion—things will sound bad long before that point is reached.

If only a tweeter is blown, that could be from an amp heavily distorting because distortion is primarily high frequencies.  But, other drivers are not getting those higher frequencies so if they blow, it is because too much power was delivered, regardless of distortion.  

I think it is safer to stay on the lower end of a manufacturer’s recommended power requirement and then don’t listen at levels where distortion is evident.

• It’s power that kills drivers
• High power amps are safe if you can fully control their output - this means know your volume knob’s "levels", and adopt patterns that prevent transient spikes - e.g. power on/off in the right sequence, mute when cueing a stylus, control LF feedback and woofer "flapping" if you have a turntable (through proper isolation) etc.
• Low power amps are safe if you keep them away from clipping conditions. At some point, power output may be low enough that even clipping doesn’t harm your tweeters - but I wouldn’t go looking to experiment on that.
• Tube amps are bandwidth limited at higher power levels, which causes their clipping wave to be *slightly* rounded compared to SS. But I can confirm, a typical tube amp’s hard-clipping still sounds like sh*t and can damage your tweeters - don’t rely on tube amps being much "safer" here.
• High efficiency speakers aren’t always correlated to higher or lower power handling. You can usually play louder safely with high efficiency. That’s why aficionados of loud sessions like me love them :)
• Tweeters typically have much lower power handling levels than woofers in the same speaker - up to an order of magnitude less. This is normally OK because like "pink noise", musical content carries much less energy above 4KHz (etc) than below - "equal energy per octave".
• When you force an amp into clipping, not only does it carry up to 2x the amount of continuous power versus unclipped (basic math - area under a sine curve versus a line), it also "rewrites" the signal to have a higher proportion of high frequency content. This is especially true for "peak" power. This is why it puts tweeters at risk - they’re not designed to take as much power as the woofers in the same speaker, so they’re sitting ducks under clipping conditions.
• Woofers are more at risk from poorly isolated turntable setups. Poor isolation and uncontrolled resonances can cause low frequency feedback. In the subsonic range, this is seen as woofer "flapping" - =-- besides power from the huge amplitude, it can cause woofers to hit their excursion limits and damage the voice coil. In the audible range 20 - 120Hz, LF feedback may be confused for ground hum at lower levels, and can even cause runaway feedback at higher levels. LF feedback can even get so bad it pushes your amp into clipping which then "suddenly" generates a HF spike (a very, very loud POP) that can kill your tweeters!

Mulveling, that is a terrific summary of the issue.