This document provides an overview of microphones, including their basic components and functions. It discusses various microphone characteristics such as frequency response, polar patterns, dynamic range, sensitivity, and self-noise. Four main types of microphones are described in detail: dynamic, condenser, ribbon, and PZM microphones. Their typical uses, frequency responses, polar patterns, and examples are compared. The document aims to educate readers on the fundamentals of microphones for music production.
2. A bit about myself
I’m Samhita Shiledar from India!
I recently completed my Chemical engineering
and working in same field now. I play piano and sing
Indian Classical Music.
This lesson is for week 1 of Introduction To Music Production at
Coursera.org
My ppt is about overview of various characteristics
of microphones and few important types.
Hope you guys enjoy ;)
3. Microphone is an INTERNAL
TRANSDUCER that converts
SOUND(pressure waves in air) into
ELECTRIC SIGNAL(voltage variations)
4.
5.
6. Way a microphone responds to different frequencies.
Some frequencies are exaggerated and others are
attenuated (reduced)
7. Frequency response may be less informatively stated
textually like so: "30 Hz–16 kHz ±3 dB".
This is interpreted as meaning a nearly flat, linear, plot
between the stated frequencies, with variations in
amplitude of no more than plus or minus 3 dB.
8. Which frequency response curve is
IDEAL?
The x axis shows frequency in Hertz, the y axis shows
response in decibels
A higher value means that frequency will be
exaggerated, a lower value means the frequency is
attenuated.
An ideal "flat" frequency response means that the
microphone is equally sensitive to all frequencies. In
this case, no frequencies would be exaggerated or
reduced .
9.
10. Polar pattern indicates how sensitive it is to sounds
arriving at different angles about its central axis
Some microphones pick up sound equally from all
directions, others pick up sound only from one
direction or a particular combination of directions.
11. Captures From All Directions
Uses: Capturing ambient noise;
Situations where sound is
coming from many directions;
Situations where the mic
position must remain fixed
while the sound source is
moving.
12. Few tips
Although omnidirectional mics are very useful in the
right situation, picking up sound from every direction
is not usually what you need.
Omni sound is very general and unfocused - if you are
trying to capture sound from a particular subject or
area it is likely to be overwhelmed by other noise.
13. Cardioid
Sound is picked up mostly
from the front, but to a
lesser extent the sides as
well.
Uses: Emphasising sound
from the direction the mic is
pointed whilst leaving some
latitude for mic movement
and ambient noise
e.g.handheld mics
14. Hypercardiod
Very directional and
eliminates most sound
from the sides and rear.
Uses: 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.
16. While any pattern between omni and figure 8 is
possible by adjusting their mix, common definitions
state that a hypercardioid is produced by
combining them at a 3:1 ratio, while supercardioid
is produced with a 5:3 ratio
17. Bidirectional
Uses a figure-of-eight
pattern and picks up
sound equally from two
opposite directions.
Uses: One possibility
would be an interview
with two people facing
each other (with the mic
between them).
18. Shotgun Microphones
small lobes of sensitivity to the
left, right, and rear but are
significantly less sensitive to the
side and rear than other
directional microphones.
USES:television and film sets, in
stadiums, and for field recording
of wildlife.
20. The difference in SPL between the noise floor and the
maximum SPL.
for example "120 dB", it conveys significantly less
information than having the self-noise and maximum
SPL figures individually.
22. Indicates how well the microphone converts
acoustic pressure to output voltage.
A high sensitivity microphone creates more
voltage and so needs less amplification at the mixer or
recording device.
24. The sound level that creates the same output
voltage as the microphone does in the absence of
sound.
Represents the lowest point of the microphone's
dynamic range, and is particularly important should
you wish to record sounds that are quiet.
26. Proximity effect is a change in the frequency response
of a microphone, having a directional pickup pattern,
that produces an emphasis on lower frequencies.
It is caused by the use of ports to create directional
polar pickup patterns
28. A lightweight diaphragm,
usually made of plastic film,
is attached to a very small
coil of wire suspended in the
field of a permanent
magnet. When a sound
causes the diaphragm to
vibrate, the whole assembly
works as a miniature
electricity generator, and a
minute electric current is
produced.
29. Condenser Microphones
A capacitor has two plates
with a voltage between
them. In the condenser
mic, 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 and therefore
changing the capacitance.
30. Ribbon Microphones
Ribbon microphones use
a thin, usually
corrugated metal ribbon
suspended in a magnetic
field. The ribbon is
electrically connected to
the microphone's
output, and its vibration
within the magnetic
field generates the
electrical signal.
31. PZM Microphones
Pressure Zone Microphones
A small condenser microphone
is mounted face-down a short
distance from the reflective
boundary plate. This creates a
pressure zone between the plate
and the mic. The microphone
detects changes in this pressure
zone, rather than the
conventional method of
detecting changes in the
surrounding air pressure (i.e.
sound waves).
33. CHARACTERISTI
C
CONDENSER DYNAMIC RIBBON PZM
CAPTURES ALL
FREQUENCIES
SPECIFIC RANGE
OF
FREQUENCIES
ALL
FREQUENCIES
SPECIFIC RANGE
OF
FREQUENCIES
SENSITIVITY HIGH LOW HIGH HIGH
PHANTOM
POWER
REQUIREMENT
YES NO YES NO
ADRESSING SIDE ADRESSED FRONT
ADRESSED
FRONT
ADRESSED
TYPICAL POLAR
PATTERN
OMNIDIRECTIO
NAL
CARDOID BIDIRECTIONAL CARDOID OR
SUPERCARDOID
UPPER
FREQUENCY
RESPONSE LIMIT
20kHz 16kHz
34. CHARACTERIS
TIC
CONDENSER DYNAMIC RIBBON PZM
USES Dynamic mics
are useful when
the sound
source is close
and reasonably
loud, and where
the sound is
predominantly
bass or mid-
range.
Capacitor mics
work well in
most situations
and have
sufficient
sensitivity to
pick up quieter
or more distant
sounds properly.
Used while
recording from
Amplifier
In the pressure
zone
microphone,
sound waves are
always in phase
and there is no
interference.
COMMON
APPLICATIONS
In recording
studios
On stage, ideal
for recording
drums and loud
amplified
instruments
In recording
studios,
favoured by
classical and
acoustic
recordists.
Conference
rooms,
podiums,
lecterns and
other installed-
sound uses.
SOME
EXAMPLES OF
MODELS
Neumann U87,
AKG C414,
Oktava MK219
Sure SM57,
Sure SM58Beta,
Electrovoice
RE20
Coles 4038,
Beyerdynamic
M130.
Audio-Technica
PRO44, Audio-
Technica
ATR4697
