A Quick Microphone Primer
02 Dec 2014
A microphone (or “mic” or sometimes “mike”) is the device that picks up sound and turns it into an electrical signal. It is known as a “transducer.”
Microphones were first developed for telephones—so-called “carbon” mics that uses grains of carbon between two metal plates. Thomas Edison is credited with being the inventor of this technology in the late 1800s.
There are several types of microphone transducers. Condenser microphones are very sensitive and capable of capturing a wide range of frequencies. They’re quite popular in recording studios. Dynamic mics are tough, inexpensive and aren’t affected by moisture. This makes them ideal for onstage use, especially by singers and as announcer mics at radio stations. Ribbon microphones used to be extremely fragile but new materials have made them more robust. They’re quite good for certain types of studio work. Piezoelectric mics are excellent for recording drums or sounds in tough environments, such as under water.
Microphones can be designed to pick up sound from all around or from a very tight vector. Cardioid mics are used mainly for vocals because are unidirectional. That is, they only pick up the sounds right in front of them and reject sounds off to the side and rear. This helps reduce feedback. At the other end of the scale are omnidirectional mics which pick up sounds equally through 360 degrees. In between, we have bi-directional mics (with their figure-8 pickup pattern), subcardioid, hypercardioid and supercardioid.