Microphones
National 5/Higher Music Technology
Kincorth Academy
Microphones
Transducer – a device which turns one form of
energy into another.
Microphones are transducer, as are speakers.
A microphone is the opposite of a speaker
and, to some extend, can be substituted for
eachother.
Which microphones to choose:
Before you select a microphone
you need to know :
 The main types of microphones
(Dynamic and Condenser) and
how they are used.
 The pick up patterns : the
directions from which a
microphone can pick up sound.
 Frequency response: How good
a microphone is at picking up
different ranges of pitch.
 Sensitivity: How well a
microphone will pick up quiet
sounds
2 Main Microphone types

Dynamic : a microphone that
generates it own power.

Condenser: A microphone that
has an electrical charge
therefore needs to be supplied
with power. They are also
known as Capacitor
microphones.
Dynamic Microphones
Dynamic microphones are
designed around a very basic
principle. They contain a
diaphragm attached to a metal
coil. As sound waves make the
diaphragm vibrate, the coil moves
rapidly in the magnetic field. This
makes electricity flow in the wires,
producing a small electrical signal.
Dynamic Microphones
Advantages of using Dynamic Microphones

Cheap to produce

Robust

Able to cope with high level signals
Disadvantages of using Dynamic Microphones

Limited frequency response (not as wide as our
ears!)
Condenser Microphones
Condenser microphones use a different
technique to convert the sound wave
into a current. Put simply; two charged
plates are held close to one another, if
the distance between them changes (e.g.
vibration) the charge will change too.
Condenser microphones require
phantom power. Phantom power is a
method that sends a DC electric power
through microphone cables to operate
microphones that contain active
electronic circuitry.
Condenser Microphones
Advantages of Condenser Microphones

Wide flat frequency response – can be used
for almost anything.
Disadvantages of using Condenser
Microphones

Delicate (easily broken)

Expensive!
Polar Patterns

Microphones are all different and pick up
sounds or Vibrations from different
directions.

Some microphones pick up sounds from any
direction, other pick up from the sounds
source. i.e. the front/ rear/sides

The Pattern of direction is called the polar
pattern of the Microphone.
Some of the most common polar
patterns

Cardoid

Omni directional

Figure of eight (bi-directional)

Hyper Cardoid
Cardoid Mics

Picks up sound in one direction - sounds are picked
up in a heart shape, mainly from the front, a little
from the sides and almost nothing from the back
Omni – directional Mics

Sensitive in all directions – pick up everything
Figure of eight mics

Picks up in 2 directions – useful
between 2 singers or drums.
Hyper Cardoid mics

Mainly picks up from the front but some
sounds from the back.
Microphone Selection
Issues regarding microphone selection:

Instrument volume

Instrument frequency range

Ambience or direct sound
Instrument Volume

Loud instruments may damage more
sensitive mics (i.e. condensers)

Soft instruments may not feed a high enough
signal into a less senitive mic. (i.e. dynamic)
Instrument Frequeny Range

Instruments generating a high frequency
range require a mic to pick up that range.
(Condenser)

Instruments with a more restricted
frequency range don’t require a wide mic
frequency response. (Dynamic)
Ambience or Direct Sound

If we want to record with some ambience
then we can choose either a mic polar
pattern that will pick up ambience, or
position the mic further from the source.

If we don’t require ambience (i.e. in the
studio) then we can choose a mic with a
tighter polar pattern and position the mic
close to the source.
Drumkit



Instruments are LOUD
Each instrument has a limited frequency range.
Perhaps some ambience required.
2 overhead condensers pick
up the greater part of the
drum kit. The distance of
these mics negate the worry
of instrument volume
Dynamic mic is placed in
or at the bass drum to
ensure a solid sound. A
dynamic mic may also be
placed at the snare.
Grand Piano


Wide frequency range
Not particularly loud.
A matched pair of
condenser mics
should be used for
this
2 different mic will
result in an
imbalance of sound.
Acoustic Guitar


Instrument is quiet
Wide frequency range
Condenser mics are
the obvious choice.
By using 2 mics
placed like this will
give us a good stereo
image.
Wind instruments


Relatively low instrument volume
Wide frequency range
Best recorded with
condenser mics.
Mics should be placed
at the apex of a
triangle where the
instrument is the
bottom edge.
Brass Instruments


Instruments are loud
Wide frequency range
Ideally condenser mics
should be used to pick
up the wide frequency
range however, it is
safer ad more practical
to use dynamic mics.
Project 1 – Radio Broadcast




Plan, record and edit a radio broadcast. A short broadcast along
the lines of Desert Island Discs, involving an interview and music
excerpts, would be suitable, but you may choose a different
theme, agreed with your assessor.
Your chosen theme must involve at least 5 different audio
tracks, at least 2 of which must be recorded using a
microphone, and there must be some creative use of sounds or
music.
You should now have enough information to make informed
choices as to which microphones you might use and how to
place them.
Obviously your choices will be limited to what is available
within the department