Transcript Microphones - Bramalea Guitar

Microphones
The basics
The microphone is your primary
tool in the sound
chain from sound
source to audio storage
medium.
Factors when capturing a sound
with a microphone:
 microphones location in relation to the
sound source
 the acoustic environment in which we
choose to record the sound source
Types of Microphones
 There are three main types of
microphones:
 1) Dynamic/Moving Coil
 2) Ribbon
 3) Condenser/Capacitor
1) Dynamic/Moving Coil
microphones
 Example: Shure SM 57
 They operate on a
magnetic principle :
movement of a copper
coil around a magnet
causes a changing flow of
electrons that represent
the sound wave
Dynamic/Moving Coil microphones
Advantages:
 durable and can withstand a lot of volume before
they distort (within their own circuitry).
 they don’t require phantom power to operate.
 colours the sound in range between 5-10khz,
this adds clarity, presence and understandability
to many vocal and instrument sounds.
 doesn’t feedback as easily as other mics
Dynamic/Moving Coil microphones
typical uses:
 mostly live situations, but they are also
used a lot in the studio.
 close mic applications (1-12 inches)
 snare drums, guitar amplifiers, kick drum,
vocals and any instrument that can play
loud.
Dynamic/Moving Coil microphones
disadvantage:
These microphones often miss the
many subtle nuances of sounds
because it takes a lot of sound
pressure to move the coil.
2) Ribbon microphones
 Example: Beyer M 160
 a metallic ribbon is
suspended between two
poles of a magnet. Sound
waves vibrate the metallic
ribbon which causes a
varying flow of electrons
to the different poles of
the magnet
Ribbon microphones
advantages:
 These microphones capture a warmer and
smoother sound than dynamic/moving coil
microphones.
 Don’t feedback much in live situations.
 Don’t require phantom power to operate.
Ribbon microphones
typical uses:
 Typically used in the studio because they are
fragile
 Used in close mic applications (1-12 inches)
 Often used for acoustic guitars. Also work well
for vocals.
Ribbon microphones
disadvantages:
 colours the sound by adding a high
frequency edge
 fragile
 will only pick up sounds that are very
close.
3) Condenser/Capacitor
microphones
 Example: Audio Technica AT 4033
 How do condenser microphones




work?
A charged electrical current is
applied to a metal-coated piece of
plastic. the coating vibrates
sympathetically in response to a
sound wave because it is very thin.
The metal-coated piece of plastic is
positioned close to a piece of metallic
alloy.
The changes in the space between
the surfaces create a changing
discharge of electrical current.
It makes an electrical version of
acoustic energy from the sound
source.
Condenser/Capacitor microphones
advantages:
 they respond to fast attacks and transients more
precisely than other mics and add little tonal
colouration
 they can be used to record sounds from a
greater distance and capture a broader range of
frequencies
 big advantage: these mics record a sound while
capturing natural ambience of a room.
Condenser/Capacitor microphones
typical uses:
 recording studios
 can be used to record almost any sound…except very
loud ones (ex. Kick drum)
 extremely effective with quiet sounds
 the perfect choice for capturing room ambience.
 almost always used for vocals , acoustic guitars and
drum ovreheads.
Condenser/Capacitor microphones
disadvantages:
 fairly fragile
 feedback too easily in a live environment
(although some have low frequency roll off
switches to help alleviate feedback
frequencies)
 require phantom power to operate
Microphone polar patterns:
 A polar pattern is the pickup pattern of the
microphone.
 There are three main types of patterns:
 1) Cardiod
 2) Bi-directional
 3) Omnidirectional
Frequency Response
 Most microphones respond to frequencies within
and beyond the human range of hearing.
 Our ears have the ability to hear frequencies
from 20-20 000 hertz .
 All microphone manufacturers provide
specifications for the frequency range of their
products.
Frequency response curve
 The frequency response curve of a
microphone shows how the microphone
responds to different frequencies across the
audible spectrum.
 A mic with a flat response adds little colouration
to the sound. Many mics drop off sharply in the
frequencies below 300 hz. Yet boast frequencies
in the area of 4000 hz.
Pre-amplifiers
 Although a microphone can be plugged directly into a mixing
board, better results are often achieved by using a pre-amplifier.
 Example: Universal Audio 2-610
Conclusion
 Effective sound miking requires lots of
experimentation.
 Most home studios should have at least
one good moving coil and one good
condenser mic.