Harvey or other mic experts, Dynamic mic quesion

[ralf]

i am giving a speech for school on the basic ideas behind microphones and how they work. (with mr. Harvey Gerst as just about the only thing on my bobliography page) and need a little more clarification on how a dynamic mic works. perhaps a way so that my audience will better understand the idea. i can understand the frequency thing and adding tuned resonant chambers to broaden the frequency responce, but can anybody thing of any other way to explain the idea of a dynamic mic? also, are all dynamics cardioid pattern. thanks for all your help.
-ralf

 

[Harvey Gerst]

well, the similarity to a loud speaker is still pretty good, and you can make a dynamic almost any pattern, short of a figure 8.