Download The loudspeaker

Educational program: Mechanic - electrician
Title of program: Technical training
II. class
The loudspeakers
Worked out: Bc. Chumchal Miroslav
Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002
je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.
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Function of loudspeaker
Types of loudspeakers
Speakers according to the frequency range
Cross- section of speaker´s basket
Students activities
Literature used
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Loudspeakers are electro- acoustic exchangers, which converted an electric
power on mechanic power in sound form.
It consist from membrane, drive unit, which is supplied by input voltage from the
final stage of the amplifier.
Earpieces are similar device.
Loudspeakers are divided by the form of emission on:
- Directly emitting ( oscillating membrane is directly connected on setting, in
which are acoustic energy emitting )
- Indirectly emitting pressure ( auditory is insert between membrane and
surroundings.
These loudspeakers have high efficiency and high emitted power.
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Loudspeakers are divided on:
electrodynamics – by oscillating coil passing current in magnetic field and it
cause membrane moving.
electromagnetic – firmly placed electromagnet attracted membrane from thin
iron sheet metal, electromagnet placed in the field cause
the coils activities and membrane moving.
electrostatic - membrane with conductive layer is placed between two
electrodes. The loudspeaker working on attracting and
repelling principle of electric charge desks .
piezoelectric – desk from piezoelectric material is mechanically joined with
membrane or it right constitute the membrane.
plasma – without membrane. Use change in air pressure, caused by arc
discharge.
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Broadband – range 20 – 20 KHz
Deep tone ( bass ) 20 – 5 KHz
Middle band ( centre tone ) 100 – 12 KHz
High tone ( high ) 2 KHz – 20 KHz, but even more
Airflowing by loudspeaker
Cross- section of speaker basket
Oscillating coil with centr- tend membrane
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Explain the function of the loudspeaker.
What types of the loudspeaker do you know? Explain theirs function.
Give the frequency ranges by individual loudspeakers.
How difference is between the loudspeaker and earpiece.
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Show and describe individual parts of loudspeaker on sample.
How behave the speaker, when the low voltage is bringing on it from the
source?
Verify on a template.
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www.cs.wikipedia.org./wiki/Reproduktor
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