If you change the diaphragm, you will change the mic's sound.

Given the tight tolerances and precise work required -- and the fact it's
highly unlikely you'll produce a useful microphone -- I can't see this as a
project justifying any expenditure of time, unless you have absolutely nothing
else whatsoever to do.

There's nothing wrong with experimenting to see what will happen -- unless the
experiment has no possible theoretical or practical outcome.

This is an Edison experiment. And that is not meant as a compliment to Thomas
Alva.