How to find resonance frequency of a diaphragm..?

What is resonance frequency ? how it differs from natural frequency ?

How to find resonance frequency of a diaphragm..? consider diameter of 75mm & cold rolled steel strip..

"What is resonance frequency ? how it differs from natural frequency "
Google it

"How to find resonance frequency of a diaphragm..? consider diameter of 75mm & cold rolled steel strip.. "

Any book on vibrations wil have it