Actually the driver I spoke of is a 2.5" dome with .75" high roll surround (forgot that it was actually 4" not 3.5") and I'd have a dome tweeter that floats on the apex of the dome, hard to explain but it would feature a neodymium magnet that is attached to the mid's dome structure. I could do a drawing of it by hand but I'm sure you get the idea. The tweeter dome would be the 1/2" center of the mid's dome with a rubber ring suspending it and the motor would be attached to the dome.
Yes I know this adds mass to the mid but I'm thinking a full aluminum dome and the plastic motor structure of the tweeter would add damping to the dome of the mid and could be made pretty light. Besides, the magnet structure would have more than enough HP to overcome the mass.
Phenom II 940 Black Edition quad core @ 3.5Ghz
2x1 gig OCZ PC26400 Platinum, 2x1gig GSkill PC26400
Some other stuff,
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