Loud Speakers

Younes Al-Sayed-Hasan

223646

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Outline

The basic principle The main components of the loudspeaker How a Speaker works? Why do we concentrate on the enclosures? Types of Speaker Enclosures Factors determine the quality of the sound

generated Conclusion

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The Basic Principle

A loudspeaker is an electromechanical device which converts an electrical signal into sound.

Loudspeakers are used in numerous applications from

hearing aids to air raid sirens Loudspeakers are the most variable elements in any

audio system, and may be responsible for marked audible differences between otherwise identical systems.

Microphone Audio Circuit Speaker

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The Main Components

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How a Speaker works?

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Resistance of a speaker Difference between large and small speaker Stereo system

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Efficiency

Definition mathematically physically How to increase it Reduce the cone resistance

o mass Increase the forceo Strong magnet

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Why do we concentrate on the enclosures?

1. Back-to-front Cancellation

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Why do we concentrate on the enclosures? (Cont.)

2. Coupling Loudspeaker to air

It can not produce a sound whose wavelength

> its diameter

Ex. 8-inch 1700 Hz

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Types of Speaker Enclosures

1. Closed Box Enclosure

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Types of Speaker Enclosures (Cont.)

2. Horn

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Factors determine the quality of the sound generated Size of the room

Speaker Placement in the room

Is the room empty or not ?

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Conclusion

Magnetic filed plays a main rule of conversion electricity into sound.

To choose your speaker, many factors must be considered like size of the room and place of the speaker.

By using enclosures, we will avoid 2 problem Back-to-front cancellation Coupling loudspeaker to air

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References

http://hyperphysics.phy astr.gsu.edu/hbase/audio/spk.html

Designing, Building & Testing your own Speaker System

By David B. Weems

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Q & A