How do condenser mics work?
All types of commercial microphones (condenser, dynamic and ribbon) work on the same basic principle – the displacement of a diaphragm (or with ribbon microphones, a long, narrow ribbon) by a sound wave is made to produce a corresponding voltage swing. Moving coil (dynamic) and ribbon microphones are electromagnetic devices and in their simplest forms can produce useable audio signals without any additional electronic help. With a condenser microphone, the microphone capsule consists of a very thin, flexible diaphragm which is spaced a minute distance in front of a rigid, insulated electrode referred to as a backplate. This diaphragm and backplate form the two plates of a capacitor, which, in the absence of a sound wave, will have a very small but definite capacitance. However, when a sound wave displaces the diaphragm, the capacitance will either be increased above or reduced below the “resting” value; depending upon whether the sound wave pushes the diaphragm toward the backplate or
