This document provides an introduction to microphones, explaining that microphones are transducers that convert sound pressure into electrical signals. It discusses that not all microphones are the same, as they have variations in how they convert sound pressure to voltage. The document outlines that the two key specifications for microphones are their polar pattern, which shows the microphone's sensitivity in different directions, and their frequency response, which shows what frequencies are exaggerated or attenuated. It then reviews the characteristics of two specific microphones, the Audix OM2 dynamic microphone that is resistant to feedback and best for stage use, and the Yeti Blue condenser microphone that is more sensitive and picks up all sounds in a room so is best for studio use.

1. Introduction to
Microphones
Prepared by (DJ Shirlee) For Coursera Introduction to
Music Production

2. What are Microphones?
Everyone thinks they understand what a microphone is and what it is used for, but
really most people don’t.
A Microphone is transducer, a device that converts variations in a physical quantity, such
as pressure or brightness, into an electrical signal, or vice versa.
Thus, converts sound pressure into voltage variations in a wire called an audio signal.

3. Not all Microphones are the
Same
Every Microphone has a little variation from the sound pressure variations to the
voltage variations. There's many variations and specifications and that really
reflecting how that signal was changed in that, in
that transduction.
So, not all microphones are NOT the same.
There are many uses for microphones, along with makes, models and prices.
However, in this presentation I am going to cover two microphones and the differences
between the two of them.

4. Two key things that every
Microphone has
Every Microphone has a polar pattern and a frequency response range.
A Polar Pattern is:
a circular graph that shows how sensitive a microphone is in different directions. Each
“circular” division represents 5dB of sensitivity, so you can see where the microphone
picks up the strongest to the weakest sounds at different points.
A Frequency Response is:
the quantitative measure of the output spectrum of a system or device in response to
a stimulus, and is used to characterize the dynamics of the system. It is a measure of
magnitude and phase of the output as a function of frequency, in comparison to the
input.
WHAT??? Let’s make that easier to understand.
Frequency response refers to the way a microphone responds to different frequencies. It
is a characteristic of all microphones that some frequencies are exaggerated and others
are attenuated (reduced). For example, a frequency response which favors high
frequencies means that the resulting audio output will sound more trebly than the
original sound.

5. Polar Patterns
The pattern response graph show where the signal is
picked up the strongest.

6. Frequency Response Graph
A microphone's frequency response pattern is shown using a chart like
the one below and referred to as a frequency response curve. 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. In this example, frequencies around
5 - kHz are boosted while frequencies above 10kHz and below 100Hz are
attenuated. This is a typical response curve for a vocal microphone.

7. Frequency Response Graph
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 (the chart above would show a
flat line), resulting in a more accurate representation of the
original sound.
We therefore say that a flat frequency response produces the
purest audio.
In the real world a perfectly flat response is not possible and
even the best "flat response" microphones have some deviation.

8. Frequency Response Graph
It should be noted that a flat frequency response is not always
the most desirable option.
In many cases a tailored frequency response is more useful. For
example, a response pattern designed to emphasis the
frequencies in a human voice would be well suited to picking up
speech in an environment with lots of low-frequency background
noise.
The main thing is to avoid response patterns which emphasis
the wrong frequencies. For example, a vocal mic is a poor choice
for picking up the low frequencies of a bass drum.

9. Lets review two
different Microphones

10. Audix OM2 Yetti Blue

11. Audix OM2
• Is called a Dynamic Mic. You usually see them in a stage setting
or being held by a singer. They are made to be held.
• You can only sing into one direction (where the black mesh grill
is). The other side (the blocks and other disturbances or feedback
from stage monitors.) Thus it’s resistant to feedback. (You know
that loud sound with mics getting hot that makes you cover your
ears.)
• This has what is called a Hypercardiod polar pattern which helps
to isolate the vocals from the rest of the instruments on stage.
• It has a frequency range of 50Hz-16Khz
• Connects to an XLR cable
• Does not require additional power

12. Audix OM2
Polar Pattern and Frequency Chart

13. Yetti Blue
• Is called a condenser microphone. You usually see them in a
studio.
• It is highly sensitive and picks up all the sound in a room. Thus,
is not idea for a singer on a stage. It would pick up sound from
the monitors and cause feedback.
• This microphone has 4 polar patterns, Stereo, Cardioid,
Omnidirectional and Bidirectional.
• Requires phantom power
• Can connect directly to a computer via USB cable and does not
require input into an audio interface box.
• It’s designed with, low distortion, high fidelity and balanced
frequency response.

14. Yetti Blue
Polar Pattern and Frequency Chart

15. Other Types of Microphones
There are many other types of Microphones used in different
settings in different ways.
Some are:
- Ribbon
- Carbon
- Piexoelectric
- Fiber optic
- Laser
- Liquid
- MEMS

16. Microphones Conclusion
I hope the information in this presentation was helpful to you.
As you continue exploring this topic, you will also learn how to
properly learn how to connect your microphone, set the gain
level and where to place your microphone or how to properly
hold and sing into them.
Thank you