3. Characteristics of
Loudspeaker
Loudspeaker is a transducer
which converts electrical
signals of audio frequency into
sound waves of the same
frequency. A loudspeaker’s
performance is determined by
the following characteristics:
4. Efficiency
It is defined as the
ratio of output
sound power to the
input audio
(electrical power)
Generally,
Efficiency of the
loudspeaker should
be maximum for a
longer lifetime
5. Noise
• The unwanted sound, not contained in the
input signal but present in the output of the
loudspeaker is called noise The mechanical
parts of the loudspeaker may vibrate at
some resonant frequency, causing noise.
6. SIGNAL TO NOISE RATIO
Signal to Noise Ratio (S/N) is the
ratio of ‘signal output’ to the
‘output of noise in the absence of
signal’. In general, the signal –
noise ratio is to be maintained at a
rate of 60dB
7. Frequency response
It indicates loudspeaker’s response for the
audible frequency range of sound. Ideally,
response of a loudspeaker should be flat
within +1 dB for the frequency range of 16
Hz to 20 kHz. However, due to mass of the
diaphragm assembly,highfrequencies are
attenuated.
8. Distortion
Any change in the frequency, phase and
amplitude complexion of the output sound as
compared to the input audio signal is called
distortion.
9. Directivity
Ratio of actual sound intensity at a
point in the direction of maximum
intensity to the sound intensity.
The loudspeaker is omnidirectional
10. Impedance
Input impedance of the loudspeaker
is represented in ohms It is an
important parameter, as its matching
with the impedance of source
amplifier is necessary.
11. 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. DRIVER:
The driver is the main element of the speaker system since it
converts line level voltage from your speaker amplifier
ENCLOSURE:
Made from wood, plastic and in some cases drywall or
concrete, the enclosure is the box or cavity where the driver is
mounted.
DIAPHRAGM:
The diaphragm is the device that convert mechanical motion
into sound waves.
CONE:
The cone is a diaphragm which is attached to the voice
coil. The cone is the part that contains a bigger surface and is
designed for maximum air movement
LOUDSPEAKER
PARTS
13. SPIDER:
The spider is located internally inside the
speaker and its main function is to preserve
the voice coil aligned properly.
SURROUND:
It acts as a suspension system that works
harmonically with the spider to bring the cone
to its normal position between vibrations.
BASKET:
Protects all the interior parts and serves as
and structural reinforcement
14. MAGNET
The magnet is made of a group of metals called
the ferromagnetic metals. These are metals
like iron and nikel. These metals have the
special property of being capable to be
magnetized.
ASSEMBLY
The diaphragm, spider and surround are
firmly attached to a voice coil suspended by a
magnetic field created by permanent
magnet. The entire assembly is free to move in
accordance with the movement created by the
voice coil in response to the electric
signal. This movement moves air in the room
to create sound.
15. Advantages
Everyone in the
room can hear
the output from
the computer
They can help
create an
ambience or
atmosphere to
accompany a
presentation
They help blind
people to use
computers,
because text can
be converted into
sound
16. Disadvantag
es
The output from the
speakers can disturb
others who are trying
to work
High quality external
speakers can be
expensive
