We should reject hard-to-drive speakers more often

which compression per se as a mechanically induced phenomenon isn’t relevant.

@phusis I don’t claim to be an expert in all measurements but this seems not to go along with what I’ve seen or measured.

At some point significantly below Xmax I believe there begins to appear evidence of compression, both within the FR and distortion.  I'm not sure how we could attribute any/all of it to thermal without tone burst testing. Take a look at the SoundStage speaker measurements, just about any of them, since they are the only mag I know of that takes compression measurements regularly.

The alternative is to own amps that will drive anything.  I was lucky enough to buy several Class  A amps that were stable into 1 ohm loads early in my audio hobby - a pair were driving the heck out of Apogee Scintillas at 1 ohm setting. 

This thread got seriously above my IQ this page, I've been able to play in waters previously too deep because my family took care of me in their passing and I was living within my means before that. Anyhow I learned the hard way about how dull and lifeless a pair of speakers can sound without enough juice. 

Here's where I get confused and I hope somebody can explain it in simple terms. Why does huge power matter when I'm listening between .5-5 watts? My speakers sounded dull and lifeless until I turned the volume past 90 db so I swap out my 300wpc and replace with a couple mc 611's and suddenly low volumes sound dynamic? Shouldn't any amp have power to spare at 1 watt?  I've shipped several very highly regarded speakers out because 250 wpc wasn't enough to 'wake them up'. I only mentioned the mac model because IDK if output transformers on a SS amp are a factor in my question.

@steve59 

https://youtu.be/AhB8uL12gtk

this may help...

... also don't confuse input sensitivity of an amplifier with its power output

@erik_squires Wrote:

There’s a reason JBL professional drivers are so expensive, and one of the main reasons that is that they are built specifically to avoid thermal compression even at constant power levels that would make most audiophile systems weep.

100% correct! See articles below: Power compression Vs Thermal distortion in loudspeaker drivers:

Mike

https://pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/Harman_Int%27l/AES-Other_Publications/LS_Heat_Dissipation-Thermal_Compression.pdf

https://www.linkedin.com/pulse/power-compression-vs-thermal-distortion-loudspeaker-alexander-wilson/