Dynamic microphone in the context of "Loudspeakers"

A loudspeaker (commonly referred to as a speaker or, more fully, a speaker system) is a combination of one or more speaker drivers, an enclosure, and electrical connections (possibly including a crossover network). The speaker driver is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound.

The driver is a linear motor connected to a diaphragm, which transmits the motor's movement to produce sound by moving air. An audio signal, typically originating from a microphone, recording, or radio broadcast, is electronically amplified to a power level sufficient to drive the motor, reproducing the sound corresponding to the original unamplified signal. This process functions as the inverse of a microphone. In fact, the dynamic speaker driver—the most common type—shares the same basic configuration as a dynamic microphone, which operates in reverse as a generator.

The Shure 55SH is a professional cardioid dynamic microphone that has been commonly used in broadcast applications since 1939. Designed by American audio products company Shure, it has been described as "iconic" in pamphlets and reviews, after the Elvis stamp issued by the U.S. Postal Service in 1993. It was widely adopted in radio, television, and recording studios. From the 1940s until the end of the 20th century, it maintained its popularity in the professional environment. Shure designed the Unidyne transducer in 1939 and then greatly improved it in 1959, based on research and development by Shure engineer Ernie Seeler.

A humbucker, humbucking pickup, or double coil, is a guitar pickup that uses two wire coils to cancel out noisy interference from coil pickups. Humbucking coils are also used in dynamic microphones to cancel electromagnetic hum. Humbuckers are one of two main types of guitar pickups. The other is called a single coil.