Take a full-range driver. Maybe one that has been thrown away for some reason other than a fault in the voicecoil. I guess the best is a Lowther driver because of the sophisticated magnetdesign. Or a Coral. Or a Fostex.
Fullrange drivers are rare today, because of the fall in popularity of the horn-speakers.
I used a Monacor SP-155X . Probably a stronger more accurate system like Lowthers' is better. I've stuck to it. Cut off the diaphragm as close as posible to the voicecoil and free the surround from the metallic frame. Use a very sharp knife.