Microphones, What are they?

Microphones are used in a very wide range of items that you use every day

The term 'microphone' was first used by English Scientist and Inventor Sir Charles Wheatstone whilst working on a plan to transmit sound-signals, music or speech over long distances in 1821.

The World's first ever microphone was invented in 1877 by David Edward Hughes in England and was referred to as a Transmitter. It was then developed further by Emile Berliner and then Thomas Edison for use in his device the Telephone.
This first microphone contained loosely packed carbon granules resting against a diaphragm. The sound waves entering the microphone caused the carbon granules to vibrate against the diaphragm which created a relatively accurate reproduction of the sound electronically.

In 1923 the first condenser microphone was developed using Electromagnetism and was referred to as a Magnetophon. This was used in all BBC studios at the time. A very similar design was that of the Ribbon microphone was also developed at the same time.

The two main types of microphone that are in use today are Condenser Microphones and Dynamic Microphones.

Condenser Microphones

These microphones are most commonly used in recording studios due to their high quality and crisp sound.
They contain a capacitor and a constantly electronically charged plate. As sound waves hit the plate they alter the current travelling through it, the capacitor then translates that change to an electronic signal. Due to this need for the plate to be constantly charged, this type of microphone requires a power source.
This power source can be from a battery or, more commonly, supplied via Phantom Power. Phantom Power is supplied to the microphone from equipment such as a mixing desk, amplifier or a Direct Induction (D.I.) Box at the standard 48 volts through the same XLR (X Latching Resilient) cable as the sound signal.
The early Ribbon Microphone as mentioned earlier, works in a very similar fashion but instead of a charged plate, they contained a strip (or ribbon) of corrugated metal.

Rode NTK
This is a very good all-round condenser microphone, particularly great for voice and singing.
Used in recording studios and radio studios.

Sennheiser MKE 600
This is a specialist condenser microphone for receiving sound waves from one direction (not the boy band). In use radio and recording studios as well as live shows as 'Overhead' mics to capture the sound from drum kits. This kind of microphone is also used on video cameras, and even by 'spies' as it will only capture audio from one isolated direction.

Dynamic Microphones

These Microphones are multi-purpose and are commonly used as stage microphones.
Dynamic Microphones use Electromagnetic Induction. A diaphragm is connected to a moving induction coil within a magnetic field. When sound waves hit the diaphragm, it then vibrates the coil within the magnetic field which is then converted to electronic signals.
These microphones are reasonably cheap, robust and resistant to moisture due to there being no power source required.

Shure SM58
This is a professional grade Dynamic Microphone. Originally designed and built in 1966 and is still after 50 years, considered the industry standard for live vocal performances due to its versatility and high quality sound. The design of this microphone has not changed since its birth.

Shure SM57
This is a low-impedance, Dynamic Microphone. Originally designed and built in 1965 and has been used by every U.S. president since its introduction in 1965 at their lecterns.
Due to its low-impedance, (meaning that it is not as sensitive), it is usually used as an instrument microphone, either directly on an instrument or used on the amplifier. If you were to use a vocal microphone on an instrument, the sound would be distorted.
SM57s are the first choice when reinforcing the sound from guitar amplifiers.

AKG D112
This is a specialist Dynamic microphone for bass frequencies. Usually used on Kick Drums or Bass Guitar Amplifiers.

Red5 Audio RVD9
This is another specialist Dynamic microphone designed for snare drums. It is specially shaped to clip onto the edge of snare drums and is designed to be extra sensitive to higher frequencies.

Of course there are a great number and variety of microphones available, I only use these as examples.

If you are confused about which microphone you should purchase, ask an expert or visit your local music shop for advice.

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