Types of Microphones-2

7/30/2019 Types of Microphones-2

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Types of Microphones

On the basis of sensitivity

Dynamic Microphone

Condenser Microphone

Electret Microphone

Ribbon Microphone

On the basis of Direction

Omnidirectional

Unidirectional

Bi-directional


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Dynamic Microphones

The dynamic microphoneuses a wire coil and magnetto create the audio signal.

The diaphragm is attached tothe coil.

When the diaphragm vibratesin response to incomingsound waves, the coil movesbackwards and forwards pastthe magnet.

This creates a current in thecoil which is channelled fromthe microphone along wires.


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Dynamic Microphones

They are versatile and ideal for general-purpose

use.

They use a simple design with few moving parts.

They are relatively sturdy and resilient to rough

handling.

Better suited to handling high volume levels, such

as from certain musical instruments or amplifiers. They have no internal amplifier and do not require

batteries or external power.


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Condensermeans capacitor, an electronic componentwhich stores energy in the form of an electrostatic field.

It requires power from a battery or external source.

The resulting audio signal is stronger signal than that

from a dynamic. They tend to be more sensitive and responsive than

dynamics, making them well-suited to capturing subtlenuances in a sound.

Prone to damage very easily.


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It has two plates with a

voltage between them.

One of these plates is made

of very light material and

acts as the diaphragm.

The diaphragm vibrates

when struck by sound

waves, changing the

distance between the two

plates.


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Electret Capsule Microphone

The electret mic uses a special type of capacitor

which has a permanent voltage built in during

manufacture.

This acts like a permanent magnet, this doesn'trequire any external power for operation.

Though, good electret condenser mics usually

include a pre-amplifier which does require power.


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Ribbon Microphone

Ribbon microphones have a very similar look to

capacitor mics.

Very popular with radio stations in the 1920s and

1930s .

They are directional in nature, meaning that you

must point them towards the sound you are hoping

to pick up.

Early models were very frail, but newer technology

has helped their durability.


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Directionality

Every microphone has a property known

as directionality. This describes the

microphone's sensitivity to sound fromvarious directions. Some microphones pick

up sound equally from all directions, others

pick up sound only from one direction or a

particular combination of directions.


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Unidirectional Microphones

They pick up sound predominantly from one

direction. They are more suitable for use insmaller studios. This includes cardioid and

hypercardioid microphones


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Cardioid Microphones

Cardioid means "heart-

shaped", which is the

type of pick-up pattern

these mics use.

Sound is picked up

mostly from the front,

but to a lesser extent the

sides as well.


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Uses of cardioid

Emphasising sound from the direction the mic is

pointed while leaving some latitude for mic

movement and ambient noise.

The cardioid is a very versatile microphone, ideal

for general use. Handheld mics are usually cardioid.


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Hypercardioid Microphones

This is exaggerated

version of the cardioid

pattern.

It is very directional andeliminates most sound

from the sides and rear.

Due to their long thin

design, they are oftenreferred to as shotgun

microphones.


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Uses of Hypercardioid mics

Isolating the sound from a subject or direction when there is

a lot of ambient noise.

Picking up sound from a subject at a distance.

By removing all the ambient noise, unidirectional sound can

sometimes be a little unnatural.

It may help to add a discreet audio bed from another mic

(i.e. constant background noise at a low level).

You need to be careful to keep the sound consistent. If themic doesn't stay pointed at the subject you will lose the

audio.

Shotguns can have an area of increased sensitivity directly to

the rear.


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Bi-directional Microphones

It uses a figure-of-eight

pattern and picks up

sound equally from

two oppositedirections.

Eg: One possibility

would be an interview

with two people facing

each other (with the

mic between them).


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Omnidirectional Microphones

It captures ambient noise.

Omni pattern mics tend to be

the most technically accurate,

but they may well pick up

sounds not intended forthem.

Omni sound is very general

and unfocussed - if you are

trying to capture sound from

a particular subject or area it

is likely to be overwhelmed

by other noise.

Types of Microphones-2

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