https://www.diyaudio.com/forums/multi-way/340786-1-cd-seos-supravox.html

https://www.diyaudio.com/forums/full-range/321786-supravox-165-alnico-vs-exc-ob.html
Hi again, I've listened extensively the GMF and Alnico versions.
The Alnico version had a very weak magnet (2.3BL) with more than 1Q in comparison to my GMF pair with 0.5Q.
The Alnico clearly won the subjective tests and listening. It is a true full-range driver with all the highs you want.
The GMF doesn't have enough highs and it sounds like a midrange driver (ironically Supravox names it as a «bass medium» driver).
The GMF also has a cold and aggressive upper-midrange which ruins the overall nice neutral timbre.
165-2000 has better tonality with naturally warmer timbre.
165-2000 has better microdynamics and better vocal expressions - probably the lower MMS is the answer but I'm not sure.