A moving coil microphone, also known as a dynamic microphone, functions via electromagnetic induction. It comprises a diaphragm connected to a small wire coil, situated within a permanent magnet's magnetic field.
Sound waves cause the diaphragm to vibrate, moving the coil within the magnetic field. This movement, in accordance with Faraday’s law, generates an electrical current in the coil, mirroring the sound wave's pattern for amplification and processing.
Dynamic microphones are favored for their robustness, straightforward design, and capacity to manage high sound pressure levels without distortion. Unlike condenser microphones, they do not require external power or batteries.
Conversely, condenser microphones operate on capacitance variations, and crystal microphones utilize the piezoelectric effect.
Consequently, the moving coil microphone is termed a dynamic microphone due to its electromagnetic induction operational principle.