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Speaker Magnets
Name: Rose Mally
Status: Other
Age: 40s
Location: N/A
Country: N/A
Date: N/A
Question:
SINCE A SPEAKER HAS A MAGNET ON THE BACK OF IT, WOULD IT
HARM THE SPEAKER OR THE DEVICE CONNECTED TO THE SPEAKER, IF THE SPEAKER
WERE TO BE MOUNTED BY THIS MAGNET? FOR INSTANCE ADHERING THE SPEAKER THE
THE REFRIDGERATOR WITHOUT BENIFIT OF SPEAKER
BOX?
THANK YOU I HOPE YOU CAN HELP ME,
ROSE MALLY
Replies:
No. The speaker magnet is there to provide a permanent magnetic
field for the the speaker coil, which is embedded in the paper of the
speaker cone. When the audio signal flows throw the speaker coil it
generates a small magnetic field the strength of which varies with the
strength of the audio signal. This small magnetic field is repelled
by or attracted to the permanent magnetic field produced by the
speaker magnet. Thus the paper cone moves away from or closer towards
the back of the speaker. Hence as the strength of the audio signal
wiggles the paper cone wiggles back and forth, and you get sound waves
that match the audio signal.
Only the field in front of the speaker magnet (where the speaker
cone is located) is of any use. The field that comes out the back of
the magnet serves no purpose, and you might as well use it to stick
the speaker to the fridge.
Grayce
No, this won't harm the speaker or anything connected to it. However,
removing the speaker from its box will change the sound it produces.
The speaker will no longer be able to produce low-frequency sound
because the air pushed from the front of the speaker will be able to
leak around the speaker to the back (which of course is pulling air
whenever the front is pushing it). So the speaker will not be able to
produce any substantial change in air pressure at low frequencies,
and thus you won't hear low frequencies from it.
There's a lot of science in a speaker box, and generally a speaker is
designed to work with a particular sort of box: vented or not vented;
if not vented, then the volume of air in the box is important; if
vented, then the vent is effectively a tuned pipe, and the size and
resonant frequency of the vent is important. In both cases, sound
reflected from the back of the box affects the motion of the speaker
cone.
Tim Mooney
No. The speaker magnet is there to provide a permanent magnetic
field for the the speaker coil, which is embedded in the paper of the
speaker cone. When the audio signal flows throw the speaker coil it
generates a small magnetic field the strength of which varies with the
strength of the audio signal. This small magnetic field is repelled
by or attracted to the permanent magnetic field produced by the
speaker magnet. Thus the paper cone moves away from or closer towards
the back of the speaker. Hence as the strength of the audio signal
wiggles the paper cone wiggles back and forth, and you get sound waves
that match the audio signal.
Only the field in front of the speaker magnet (where the speaker
cone is located) is of any use. The field that comes out the back of
the magnet serves no purpose, and you might as well use it to stick
the speaker to the fridge.
Grayce
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Update: June 2012
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