Through the process of electromagnetism, dynamic microphones are able to convert sound into electrical signals. The assembly of a dynamic microphone is simple and quite similar to the structure of a loudspeaker. Its construction is delicate and it responds to low pressure levels. In fact, these are light enough to react to high frequencies without any mechanical resistance. The high quality of their sounds has taken them to popularity in radio and broadcasting.
Characteristics
For starters, dynamic mics have low sensitivity, are susceptible to interference, sturdy, and resistant to heavy handling. Also, they are capable of tolerating high amplitudes of sound level. In addition, they have a smooth response and are the most popular microphones on the market. They cover the same range as their capacitor counterparts. This type of microphones is most used in classical music recordings, in dance music bands, and in settings that require mixing drums and brass instruments.
They fall under two categories: coil dynamic microphones and ribbon-based dynamic microphones.
Coil Dynamic Microphones
Firstly, coil dynamic microphones include a cone with a coil in one end, suspended with a permanent magnet. When the coil moves inside the magnetic field, an electrical current appears due to the pressure applied. The extremely low output from the coil is fed into the microphone amp and then lifted. In this way it generates a line-level signal possible to hear by the human ear. The result is a production of sound on the backside of the microphone. This sound alters the directional pattern of the device. Coil-based microphones are quite popular on live performances because they don’t need external power and they tend to be quite resistant.
Ribbon-based Dynamic Microphones
Secondly, ribbon-based dynamic microphones also operate with electromagnetic induction. Ribbon transducers use a narrow strip of thin aluminium foil that works as an electrical conductor. This produces movement within the magnetic gap. A ribbon transducer can accurately follow the movements of the sound waves. However, this type of dynamic mic is extremely fragile and limited in terms of treble response. Users save them for special applications mostly.
