Thermal Distortion your loudspeaker most likely suffers from it. But do you care?

ditusa,

Thank you for the interesting paper you attached to one of your postings.  I just got around to reading it and it is very interesting. Not only does heat affect the voice coil, to the extent the heat gets into the magnetic structure, flux is affected which further adds to thermal compression.  I also did not consider that changes in Thiele-Small parameters also add to compression.  Finally, I might add that although the paper does not mention this, heating of the components in the crossover will add to compression.  

This thread really separates the knowledgeable from the clueless.

Who's on first?

heating of the components in the crossover will add to compression

Heat also alters the XO points and not uniformly between drivers.

Your welcome!  

@larryi

Not only does heat affect the voice coil, to the extent the heat gets into the magnetic structure, flux is affected which further adds to thermal compression.

Yes That is one of the many reason for using ALNICO in permanent magnet speakers, it's impervious to heat so it's flux is not affected by the change in temperature.

Finally, I might add that although the paper does not mention this, heating of the components in the crossover will add to compression.  

You are correct I think you can fix that with an active crossover. 😁

You’ve got more to worry about in passive crossovers than heat

VERY good information to add to my (limited) knowledge base.

Might also explain why it's extremely difficult for me to endure the 3rd (and featured) act of live performances?  As the evening progresses, the "tech" running the sound board bumps the sound levels up a few db during intervals.  By the time it gets to the 3rd set, it's downright painful.  The additive effects of distorted, dynamically compressed sound accompanied by much louder average sound levels is not what an aging audiophile appreciates at a live music venue.