SPEAKER SCIENCE
There are many types of
speakers
. What all
speakers have in common is that they convert
fluctuations in current into sound vibrations.
Speakers can be built in many different ways.
But all have a large, flexible membrane to set
the greatest possible quantity of air into
vibration.
Simple speakers use the
piezoelectric
effect
for this: Certain materials become
elastically deformed under the influence of
current fluctuations, rising and falling in
rhythm with the fluctuations and thereby
creating sound vibrations in the air.
GEEK
OUT!
Better speakers, by contrast, have
a movable suspended coil made of
fine wire, with the coil positioned
near a strong magnet and
connected to the membrane. When
current flows through the coil,
the coil itself becomes magnetic.
As this current fluctuates, the
magnetism rapidly changes in
strength and direction, so the
coil is attracted one moment by
the external magnet and repelled
the next. It is these movements
that are transferred through
the membrane to the air. Ears
interpret the vibrations in the air
as sound.
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