Matching speaker to amplifier?

look at the speakers impedance...is it flat and stable at 8 ohms or does it look like a ski jump dropping down to 2 and up above eight? crazy curves will like high current ss amps that "double down" as their impedance drops while you can run a low power tube rig on something that's 8 ohm stable. efficiency comes into play but not as much as the impedance imho

My default position on this kind of question is as follows:

I highly recommend the white papers on the website of Atma-sphere, the amplifier manufacturer called Debunking Common Power Amplifier Myths and Voltage and Power Paradigms. The pair of white papers, taken together, are very interesting and highly instructional.

Years ago I asked ProAC which amps they used to test there speakers. Would not tell me, as they felt it was a matter for MI15, or a break in to the factory.