It has been ages since the first microphone were invented; the name microphone was coined in 1827 by Sir Charles Wheatstone and several kinds of microphones have emerged after Thomas Edison’s carbon microphone (1876) for all sorts of uses. From the fluid microphones that made unintelligible sound (until the coming of Alexander Graham Bell) to condensers for studio and laboratory recording purposes and to laser microphones invented for spying devises and nowadays, we have contact microphones which can be used to record the heart beat of snails. But for the sake of this magazine, we shall limit ourselves to a few commonly used microphones. But first, what are microphones?
Microphones are input devices that convert sound waves into an equivalent electrical energy. In a simplified way, a microphone is used to capture the sound an instrument or voice makes either for recording or for a live application. Having the appropriate set of microphones as well as other appropriate components for your job, will enable you deliver an effective and pleasant sound to the hearing of your audience.
TYPES OF MICROPHONES
DYNAMIC MICS: These categories of microphones are till date the most widely manufactured and commonly used types for sound reinforcement. If you were to fragment a dynamic microphone, you’d come across a capsule, in it lies a moving coil which is being pushed by a diaphragm. When sound hits the diaphragm it moves gently which allows for a minute electrical charge to take place along the coil. As a result of this action, an electrical pressure is sent to the console which is then being preamp to increase whatever sound is coming in to a more audible level.
RIBBON MICS: Ribbon microphones are another form of dynamic microphones but are fragile and rare nevertheless, they have had a name for a superb sound quality. They rely on step-up transformers usually built into the microphones to get the sound to a level to be heard.
CONDENSER MICS: Condenser microphones are very responsive to a wide range of sounds as a result of how they were designed. They are capable of extreme high-quality output and are more responsive to high frequencies. Condenser microphones are powered by phantom power that is, they require a power supply for the microphone either directly from the console (9v-48v) or an external battery being inserted into the microphone. It is interesting to note that the entire range of orchestral instruments would utilize the condenser microphone as well as the guitar during recording and live applications.
A lapel microphone is a variation of a condenser microphone which is usually clipped onto a person’s shirt with a cable that leads to its transmitter.
The Shotgun microphone is another condenser microphone variation which is mainly used for broadcast and film. These extended and thin microphones are capable of picking sound frequencies over a fair distance which makes them vital when trying to segregate one sound from another.
POLAR/ PICKUP PATTERNS
All microphones can be manufactured to have a unique pickup pattern that fits whatever purpose for which that microphone was made. Some microphones could pick all frequencies available in a room whereas others could only respond to sources directly in front of them. Having said these, we will move on to discuss the various polar patterns.
TYPES OF POLAR PATTERNS
Cardioid microphones are directional with a heart shaped polar pattern. What this means is that they pickup sound mainly from the front and are least sensitive to sound from the back. The good thing about the cardioids microphones is that they can be positioned to mic or record a particular voice or instrument while ignoring any unwanted sound.
Bi-directional microphones have the shape of figure of 8, such microphones pickup from the front and rear and have null points on both sides. They can be used to mic two vocalists facing each other.
Omni-directional microphones pick up sound from all angles, virtually giving a 360 degree coverage. They are good for picking up the tone and reverb of rooms and tend to sound very natural when positioned close to instruments.
BASIC RULES WHEN DEALING WITH MICROPHONES
During sessions of recording, the engineer always aim to get the overall sound of the voice or instrument he/she wants to record, for this reason, the engineer needs to position the microphone away from its source. Except, the engineer needs to get a localised or a particular sound from the source that he/she will have to position the microphone extremely close to the sound source. For example, if I want to get a bass sound from a vocalist, I’d rather place the microphone to the point that the vocalist’s lips will have to touch the microphone basket.
Another important rule while recording which should be in mind is the 3:1 rule. This rule comes into play when using 2 microphones to get different sounds from the sources. The rule simply states that if microphones were 1m away from the source, the microphones should be 3m away from each other in other for each microphone not to overlap the other.
BEFORE PURCHASING A MICROPHONE
There are several factors which one has to look out for before making a purchase, before purchasing, you should consider the purpose which the microphone is out to serve. Is it for worship, studio recording/mixing, broadcasting, etc? One could ask for technical support if one is new in the subject. Then ask yourself how many microphones are needed for this purpose. Quality/output is another factor which should not be taken for granted, this is because we have to think of our long-term investments. Price/cost is another factor. Compare prices from different manufacturers.
I hope you do find the right bargain for your microphones.