A moving coil microphone functions on the basic principle of Electromagnetic induction. It has a copper wire coil, which when moves in the magnetic field a voltage is generated. Then it is induced in the coil in proportion to its amplitude of vibration, which, in turn, depends on the sound pressure. A moving coil microphone contains a diaphragm, which is exposed to sound waves. The diaphragm carries a coil placed in the magnetic field.
Moving coil microphones are cheap and forceful and they are famous for their excellent performance in live presentation and touring. They are especially suited for the close miking of Bass and Guitar speaker cabinets and Drum kits. They are also ideal for live vocals as they have a resonance peak of around 5k hz, providing an inbuilt boost, which on the other hand improves speech, or singing brilliantly.
You will find there are many kinds of moving coil microphones. One of them is the Shure SM58, which is a classic microphone. This is an industry standard microphone designed mainly for live performances. They are strong and yet they do not require high power. However, the drawback of these microphones is that the coil reduces the high frequency response. Therefore, they are not much suitable to be used in the studio applications, where the main focus is on the quality and subtlety. These are of the basic importance, including, high quality vocal recording or acoustic instrument mic voicing. But they are used in some cases in studios for instrument recordings. Moving coil microphone is also the first choice for the snare drums, and also very popular on electric guitar amplifiers.
One of the biggest advantages of a moving coil microphone is the rugged construction of these microphones for rough use. They are also ideal as they have high sound pressure level. It is a strong device and it is impossible to break one without intentionally doing so. They are durable and can withstand pressure of any kind.
Because of these advantages and basic features moving coil microphones are commonly found in road cases of touring set ups. These devices are designed in such a simple design and the production of moving coil microphones are at a great number, therefore, the cost of these microphones is fairly affordable.
Even though these microphones are commonly used for various live performances and they are ideal device for it, yet they do have their disadvantages too. One of the major disadvantages of this microphone is that the coil is relatively heavy and makes it difficult to move quickly. And as a result it makes it difficult to get a high frequency response from these kinds of microphones. Similarly, since the output of the coil is dependent on its velocity, very low frequencies will result in little output as well.
When you look into the above mentioned advantages and disadvantages, you can find the disadvantages are outnumbered by the advantages; then you can say this is mainly the reason for the moving coil microphones becoming a famous device. They are ideal for musical instruments pickups and vocals. And they are also ideal for live sound reinforcement.