I've searched though I'm not sure enough but I just can't find the answer. MI drivers are made for music production and not really for music reproduction.
1) The magnet structure and frame are essentually the same. E-1XX reconed to a 22XX.
2) I assume a spider is a spider is a spider
3) Cone materials are basically the same. Paper or treated paper.
4) That leaves voice coil. Different windings?
5) I guess I forgot that ringing metal dust cap. That's it isn't it? The holy grail of secrets. Swap out the metal dust cap for a paper cap and life is good. HA!
If I recone a E-110 to a 212X the bass & midrange have different characteristics. VC?