Microphones are almost always necessary in many types of situations. From rock concerts to classical orchestras and even in worship environments knowing the types of microphones, what they do and how to properly use them is key for any worship leader or sound engineer.
So, what exactly is a microphone?
A microphone is a transducer that takes an acoustical sound and converts it into electrical energy. A microphone is the opposite of what a loudspeaker is, as it converts electrical energy back into acoustical energy. Three most common microphones in use today are the moving-coil or dynamic, the ribbon and the condenser microphone.
The moving-coil or dynamic microphone
From hear on out we will call the moving-coil microphone by the more popular name a dynamic microphone. A dynamic microphone is a very popular microphone that is very robust and very suitable for a vocal microphone. They are relatively sturdy and can handle a lot of stress and can handle high volume levels. It is very common to find dynamic microphones with wire-mesh wind shields. A very popular dynamic microphone used in the worship environment as a vocal microphone would be the Shure Beta 58 or SM-58 microphone.
To find out how they work let’s take a trip back to your science class, when you learned about how a magnet moved near a coil of wire that an electrical current is generated in the wire. The microphone diaphragm is attached to the coil and when it vibrates, the coil moves back and forth past the magnet creating an electric current.
The capacitor or condenser microphone
Again, the more popular name for this microphone is the condenser microphone so we will continue to refer to it as so. A capacitor is a component in a condenser microphone that stores energy. Condenser microphones require a power source from an external source such as a battery. Because of this condenser microphones have a much stronger signal than a dynamic microphone.
A condenser microphone is a very complex device. Taking a trip back to science class again you will remember that a capacitor is nothing but two metal surfaces facing each other story energy. Inside a capacitor is a very thin foil that is mounted on the front of a metal disk. They are so close that they almost touch each other. The foil is called the diaphragm and the plate is called the electrode. When sound wave hit the foil it causes it to vibrate changing the capacitance and transforming the acoustical energy into an electrical signal. This energy is a little weak, therefore it must be amplified with an external power source such as a battery or phantom power. Phantom power is voltage that is supplied from a preamp or a mixer through a normal 3-pin XLR cable.
The condenser microphone was invented by a guy by the name of George Neumann, who started the company by the same name in the late 1920s, and are still popular today.
The ribbon microphone
The ribbon microphone is a type of dynamic microphone that consists of a long thin strip of metal foil, that is corrugated, and is tensioned between two opposing magnets. The opposing magnetic poles on the magnets create a magnetic field across the ribbon so when sound waves hit it a current is created. The electric output of the ribbon microphone is small so they have a built-in transformer stepping up the output. Ribbon microphones are very sensitive, but also very fragile and is probably one of the reason they are less popular in the worship environment.
Directional responses of microphones
Microphones are designed to have a specific directional response pattern and are described by polar diagrams
Omnidirectional microphones ideally pick up sound equally from every direction. This means that whether the user speaks or sings into the microphone from straight on, from the left, right or back, the microphone will pick up the signal equally. For this reason omnidirectional microphones have great flexibility.
Figure-eight or bidirectional pattern
A Figure-eight or bidirectional microphones pick up sound from the front and back great but poorly from either side.
Cardioid or unidirectional pattern
A cardioid or unidirectional microphone picks up sound in one directional (the front) and in a heart-shaped pattern, while the sides are ignored.
The Hypercardioid, is similar to the polar pattern of a cardioid and is very directional and eliminates most sound that is coming in from either side and the rear.
Two of my favorite microphones in the worship environment are the Shure SM58 and the Shure SM-57. They both run around $100 a piece and are the industry standard for vocal and instrument use. They aren’t top of the line but work very well and can withstand abuse I have seriously dropped, kicked and thrown these microphones and they still work. They both are dynamic microphones with a cardioid pattern. The SM58 has a metal mesh ball filter and the SM57 does not. You can pick these up at your local Guitar Center, on Amazon.com or Sweetwater.com