LaudSpeaker Prsentation: 1.Introduction 2.History 3.Explanation of Loudspeakers 4.Principle of Loudspeakers 5.How speaker make sound? 6.Characteristics of Loudspeakers 7.Classification of Loudspeakers 8.Types of Loudspeaker Thanks a lot.

2. LOUDSPEAKERS
Designed By:
Hamza Saeed

3. Introduction
 Loudspeaker is another very
important device present in any
audio and video system such as
public address systems, radios,
televisions etc.
 A loudspeaker is simply a device
that converts electrical energy into
sound that is amplified so that it can
be heard from a greater distance than
the original sound would allow.
Fig(3.1)
Laud
Speaker
Electrical
Signal
Fig(3.2)

4. History
Johann Philipp Reis installed an
electric loudspeaker in his telephone
in 1861
The first practical moving-coil
loudspeakers were manufactured by
Danish engineer Peter L. Jensen and
Edwin Pridham in 1915
Fig(3.3)

5. Explanation of Loudspeakers
 The Speaker Cone : This component
is responsible for pushing air and
creating sound.
 Magnet and Voice Coil: These
elements convert electrical energy into
mechanical energy (motion).
 The Spider: This part is what holds
the speaker cone in place in a
suspended configuration, while also
allowing for some movement.
Fig(3.4)

6. Basket: The sturdy metal frame (basket) is
glued to the top plate and it holds the speaker
cone (diaphragm), that is enclosure in which
the whole system is installed.
Dust Cap: It protects the inner mechanics
(such as the pole pieces and the voice coil)
from small particles (which can cause rubs)
and other contamination.

7. Principle of Loudspeakers
 Loud Speaker work by converting electrical
energy into mechanical energy(motion).
 The mechanical energy compresses air and
converts the motion into sound energy or
sound pressure level (SPL).
Fig(3.5)
 Loud speaker is also known
as Transducer.

8. How speaker make sound?
 A coil ,called voice coil is placed in a uniform
magnetic field.
 When an electric current is sent through a coil of wire,
it induces a magnetic field.
 Like charges repel each other and different charges
attract each other , same as a speaker work.
 As an audio signal is sent through the voice coil and
the musical waveform moves up and down, the voice
coil is attracted and repelled by the permanent
magnet. Fig(3.6)
 This makes the cone that the voice coil is attached to move back and forth. The back
and forth motion creates pressure waves in the air that we perceive as sound.

9. How speaker make sound?
Diagram 2:

10. 1.Efficiency:
It is defined as the ratio of output sound power to the input audio(electrical power).
2. Noise:
The unwanted sound, not contained in the input signal but present in the output of the loudspeaker is called
noise. Noise determine the SNR of loudspeaker.
3. Frequency response:
It indicates loudspeaker’s response for the audible frequency range of sound. It require to be flat for whole Audio
Range.
4. Distortion:
Any change in the frequency, phase and amplitude complexion of the output sound as compared to the input
audio signal is called distortion.
5. Directivity:
• Unidirectional
• Bidirectional
• Omnidirectional
Characteristics of Loudspeakers

11. 6. Impedance:
This input impedance of the loudspeaker is represented in ohms and is an important parameter,
as its matching with the impedance of source amplifier is necessary.
7. Power handling capacity:
A loudspeaker can handle some maximum power (indicated in watts) for which it is
designed. Power more than the maximum will damage the speaker.

12. 2. Indirect Radiating
 A type of loudspeaker which uses a moving coil placed in a magnetic field.
 Then it is transformed to air in the listener area via this horn.
 it radiates sound power to the air in space not directly from the diaphragm but indirectly through the horn.
 This is the reason why the horn type loudspeaker is called “indirect radiating loudspeaker”.
For Example:
a) Horn type Loudspeaker
Classification of Loudspeakers
1. Direct Radiating
 In this loudspeaker, the vibration of coil are transmitted to
attached cone which create the sound in the air for listener.
 Hence it is called ‘direct radiating type loudspeaker’.
For Example:
a) Moving Coil Cone Type L.S
b) Electrodynamic Type L.S

13. Types of Loudspeaker
1. The Dynamic Driver. ...
2. Dynamic Compression. ...
3. Problems with Dynamic Drivers. ...
4. The Electromagnetic Dynamic Driver. ...
5. The Planar-Magnetic Transducer. ...
6. The Heil Air Motion Transformer. ...
7. The Electrostatic Driver.

14. Thank You