ABSTRACT
This chapter discusses the various microphone types and how they work internally. Most microphones employ a lightweight diaphragm that vibrates in response to pressure from the acoustic waves striking it. Like a piezo phono cartridge, a crystal microphone generates voltage when the diaphragm flexes the crystal. In practice, many microphone diaphragms are more like a drum head; the diaphragm stretches slightly, and the center is displaced by sound waves even though the edges are secured to the housing. A cardioid pickup is created by drilling a pattern of holes in the back plate to allow sound waves to reach the diaphragm through that path, similar to the rear vents in a dynamic microphone. Like a dynamic microphone, a guitar pickup consists of a magnet and coil of wire, but with a guitar pickup, both the magnet and coil of wire remain stationary, while the steel string moves through the pickup’s magnetic field.
