I though feedback was to keep the current constant in a current amp?
From:
https://www.stereophile.com/reference/1106hot/index.html
Voice coils are designed to with stand 200 degrees C. Copper is 1.7 times more resistive there than at 20 degrees.
Going from 20 degrees to 200 degrees a 100 watts voltage drive will decrease its power to 58 watts while a current drive will increase the power into the voice coil to 170 watts, a substantial amount. The powers got to go somewhere and it will just add more heat to the voice coil.
I agree these circumstances are very rare at home but you get people with big amps at parties turning it up to 11 and poof.
And I sure wouldn't want current drive in a PA system.
Short version: You are right, I was wrong. Oops.
Yes, the feedback is to keep current constant, and I was not arguing that the power does not go up assuming current is held constant. Reading back my response was poorly written, sorry. I was thinking (or maybe I wasn't) in normal use a voice coil rarely exceeds 100 degC (but that's a number I pulled out of a foggy memory so may well be wrong) so the likelihood of destruction was low. I skimmed a bit more, and as you and others have stated, current drive amps do best with drivers exhibiting fairly constant impedance and the ability to handle the extra power, mainly planar-dynamic and compression drivers in my quick search. What I found puzzling is applying to compression drivers, often used for sound reinforcement (PA systems and such), where I'd expect the extra power would be a bigger problem due to the high average power...
Mea culpa.
Turning up to 11 at parties is an issue no matter the amp... I got a lot of business in my college days as a repair tech from beer parties.
For others, here are the usual simplified op-amp pictures of voltage and current drive. In voltage mode, the output is a voltage, and feedback is the output voltage through a voltage divider. In current mode, the output is a current, and feedback is sensed as a voltage across a known resistance using basic Ohm's Law: V = Iout*R. Since most speakers are designed for voltage drive and exhibit wide impedance variations driving a typical speaker with a current may not provide optimal results (also stated earlier).
The voice coil resistance usually increases as temperature increases (most all metals have positive temperature coefficients). Recall power P = V^2 / R = I^2 * R so as R increases, power goes
down if voltage (V) is held constant, but goes
up if current (I) is held constant.
Teach me to enter a speaker discussion, not my area of expertise - Don