Roving Sign, the term "dynamic" is a misnomer in the first place, since all microphones have at least one moving part and are therefore "dynamic" in that sense. Even if a microphone didn't have any internal moving parts, you could pick it up and throw it across the room, which would make it "dynamic" in yet another sense.
But seriously, the term is generally applied to any microphone in which the electricity is generated via magnetism. Usually this takes the form of a moving coil or an aluminum ribbon suspended within the field of a permanent magnet--a miniature loudspeaker in reverse. As the diaphragm or ribbon is moved by sound waves (or perhaps by some idiot blowing into the mike to see whether it's on--it's amazing how many people seem to think that that's an insider's trick, a very smart thing to do), the coil or ribbon cuts across the magnetic lines of force, and current is induced in said coil or ribbon.
So of the types you mentioned, moving coil and ribbon microphones are considered "dynamic." Crystal microphones aren't, though, since they're based on the piezoelectric effect--the crystal itself generates a tiny current when flexed by sound energy (or perhaps by a sadist with pliers).
--best regards
Topic: Controlled Magnetic Microphones? Are they "dynamic" mics? Help! (Read 3193 times)