This not good, a Alnico magnet require other project diferent from Ferrite, the way to design the mobile parts of a Ferrite and Alnico speakers are very different not mentioning the critical VC, according the old school from 1940/50.
I'm not one to respond to lots of forum posts on my drivers, but I'll make an exception:Of course we didn't reuse the voicecoil from the ferrite magnet.
We also used a different spider!
We took what we loved most about the Betsy, and voiced the alnico version appropriately.
Disclaimer: Wildburro is a spare time | hobby activity. I try and have fun, meet great people, smile while listen to warm music on cold nights. Hobbies should be fun, right?