Principle: sound pressure changes the spacing between a thin metallic membrane and the stationary back plate. The plates are charged to a total charge
where C is the capacitance and V the voltage of the biasing battery.
- Best overall frequency response makes this the microphone of choice for many recording applications.
- May pop and crack when close miked
- Requires a battery or external power supply to bias the plates.
A change in plate spacing will cause a change in charge Q and force a current through resistance R. This current "images" the sound pressure, making this a "pressure" microphone.