Dynamic Microphones

Of the three main types of microphones available, let's start with the microphone most people are familiar with, the dynamic microphone. Dynamic microphones are the microphones you've most likely come into contact with if you've ever played on a stage, sung, or spoken into a microphone. Dynamic microphones are the ice cream cone–shaped microphones that we all know and love.

Construction

What makes this microphone “dynamic” is the way in which it picks up the sound and translates it into an electrical signal. It has a small diaphragm made of plastic, usually Mylar (a type of plastic), that is placed in front of a coil of wire, called the voice coil. The voice coil is suspended between two magnets. If you remember from high school physics, when you move wire between magnetic fields, you can induce current. As sound hits the diaphragm, the voice coil moves and induces current. The current is fed down the microphone cable into your mixer or recording device. Voilà, sound!

Using Dynamic Microphones

Dynamic microphones are great for vocals, miking amplifiers, and close-miking drums. Dynamic microphones are durable, well constructed, long-lasting, and—the best part—cheap. You can get a great microphone for under $100. A famous dynamic microphone, the Shure SM57, which is great on guitars and snare drums, can be found in just about every studio in the world. Shure also makes the SM58, which is used for speech and vocals in live settings, such as concerts.

Another type of microphone is the ribbon condenser. Instead of using a traditional diaphragm as the dynamic and condenser microphones do, a ribbon condenser uses a very thin and flexible ribbon to pick up the sound. Ribbons are very fragile and can be damaged with mishandling. Recently, budget-priced ribbon condensers started to appear on the market.

Dynamic microphones hear sound in cardioid patterns, which means they hear sound only directly in front of them. This makes them great for close-up miking situations, such as vocals, amplifiers, and drums, situations calling for nothing but the sound coming from the source with little or no ambience. One of the most important points about the dynamic microphone is its ability to handle extremely high sound-pressure level (SPL). As a result, you can use them in loud situations. However, dynamic microphones don't have full frequency response, which is helpful in many situations, and all are a bit different in the frequency levels they respond to. For example, the AKG D112 Kick Drum microphone emphasizes the bass frequencies and falls off at the high range, where there is little signal from a bass drum.

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