A microphone is an electronic device used to capture sounds. There are multiple types of microphones, each specifically designed for a certain usage environment. Dynamic microphones are one of the most common types of microphones because of their simple construction and their features. Dynamic microphones are also known as velocity-sensitive microphones.
Dynamic microphones use the exact opposite working principle of a loudspeaker. While a loudspeaker consists of a moving coil that vibrates when a current is sent to it, thus generating sounds, a dynamic microphone uses the sound that needs to be recorded to move the coil, generating an electrical current of a certain frequency.
The simplicity of construction is the main advantage of this type of microphone. Because of their simple working principle, troubleshooting such microphones can be quite simple. Dynamic microphones are considered passive devices, since they don't require external power to operate. One of the most important features of this type of microphone is that it can be used both as a microphone and as a speaker. Dynamic microphones are also scalable and can be built in various sizes.
A major disadvantage of dynamic microphones is their reduced accuracy compared to other types of microphones. This is because the moving coil cannot accurately capture multiple sounds of different frequencies that are played simultaneously. A labyrinth housing is generally used to counter this effect, but the overall efficiency of a dynamic microphone remains lower compared to other types of microphones. Also, the output current of a dynamic microphone is very low, and so it requires a lot of amplification. This can add noise to the sound, seriously affecting its quality.
Dynamic microphones are used in a variety of fields. The fact that they don't need to be powered makes them ideal for portable devices. Also, dynamic microphones are used in intercom systems because they can serve as both the microphone and the speaker. Dynamic microphones are also used in recording studios, except for the recording of high frequencies, as their construction limits them from accurately capturing such frequencies.