1. Electronics & communication sem: 5TH year: 2014-15 AUDIO VIDEO SYSTEM
Prepared By:
Avdhesh Soni ( )
Sarthak Patel ( )
Akshay Parekh ( )
Fenil Sachla ( ) Guided By:
Canath Christian ( ) Rinkal Shah

2. ELECTRONICS AND COMMUNICATION
Contents
Anatomy of microphone
Types of Microphone
Recording Pattern
Characteristics of microphone
Direction
Application

3. Anatomy of a Microphone

4. Anatomy of a Microphone

5. Types of Microphones Dynamic microphones –
a physical cone acts like a lens to concentrate the incoming sound waves.
Ribbon microphones –
Ribbon microphones consist of a thin strip of metallic foil suspended in front of a magnetic plate.

6. Types of Microphones Wired microphones :
wired mics offer reliable connections and can cost less than wireless mics
Handheld wireless :
are literally held in the hand of a presenter or a vocalist. In this way the microphones can be used as a prop in a performance

7. Types of Microphones Condenser microphones :
Rather than a vibrating wire coil, condenser microphones
have a thin diaphragm and solid back plate which make
up an electronic component known as a capacitor.
Hands-free wireless :
come in three popular configurations, lapel (or lavaliere) wireless microphones, collar wireless microphones and headband wireless microphones

8. Recording Patterns Unidirectional (cardioid)
pickup patterns are most sensitive to sound produced on the front side of the microphone capsule. Super-cardioid pickup patterns have a greater sensitivity than cardioid pickup patterns
Omnidirectional (boundary)
pickup patterns are sensitive to sound from all directions of the microphone capsule
Bidirectional (figure 8)
pickup patterns are sensitive to signals emanating from the front and back sides of the microphone capsule while rejecting sounds from the left and right sides of the microphone capsule

9. Characteristics of Microphones
RIBBON Microphone
Sensitive to phyisical shock
Sensitive to input overload
Sensitive to temperature
change
No battery needed
Higher quality sound at
greater distances

10. Characteristics of Microphones
oldest and simplest microphone
that uses carbon dust.
the technology used in the first 
telephones and is still used in some
telephones today.
The carbon dust has a thin metal or
plastic diaphragm on one side. As
sound waves hit the diaphragm, they
compress the carbon dust, which
changes its resistance. By running a
current through the carbon, the
changing resistance changes the
amount of current that flows.
CARBON Microphone

11. Characteristics of Microphones
FIBER OPTIC Microphone
fiber optic microphones can be extremely small, and they can
be used in electrically sensitive environments.
They can also be produced with no metal, which makes them
very useful in magnetic resonance imaging (MRI) applications
and other situations where radio frequency interference is an issue. 

12. Characteristics of Microphones
LIQUID Microphone
used a metal cup filled with water and sulfuric acid. A diaphragm
was placed over the cup with a needle on the receiving side of
the diaphragm. Sound waves would cause the needle to move
in the water. A small electrical current ran to the needle, which
was modulated by sound vibrations.

13. Characteristics of Microphones
ELECTRET Microphone
most widely used microphones on Earth
cheap and relatively simple, electret mics are used in cell phones,
computers and hands-free headsets
a type of condenser microphone in which the external charge is
replaced with an electret material, which by definition is in a
permanent state of electric polarization  

14. Omnidirectional Microphones
collects sound from all around 360 degrees.
A true omni-directional mic is a pure pressure transducer - it strictly measures changes in pressure without any regard to the direction that the wave is traveling.
microphone can be
share by the group.

15. Bidirectional Microphones
Bidirectional = two directions.
A true bidirectional mic can be a pressure-gradient or velocity transducer, meaning its response to the sound will depend on the direction the sound wave is coming from.
The diaphragm is completely open on both sides so that it can react to pressure changes on either side of the diaphragm

16. Unidirectional/Cardioid
Unidirectional = one direction
collects most of the sound from the front, and very little from the back and sides.
The microphone has a null at 180-degrees - it will not respond to sound approaching directly from the rear.

17. Applications Telephones, Hearing aids,
Public address systems for concert halls and public events, 
Motion picture production,
Live and recorded audio engineering, 
Two-way radios

18. Applications Megaphones, radio and television broadcasting
In computers for recording voice, speech recognition

19. THANK YOU