What is the function of a magnet in a speaker?

Question

What is the function of a magnet in a speaker?

Answer 1

to provide permanent magnetic field to the coil of the speaker which moves as per the signal current it creates fluctuating magnetic field in the coil by the signal current so coil is moved along with speaker cone , if permanent magnet field is not present it can not move the coil.

Answer 2

To create a magnetic field....

That way the voice coil wrapped around the plastic cylinder will move back and forth when electricity is applied to the coil.

The cylinder is attached to the cone which then moves back and forth compressing and expanding the air around it, which is what our vocal cords do too...of course it vibrates the air differently than a speaker does, but the air is vibrated

none-the-less

Answer 3

It attracts the tiny bones in each of your ears and makes you attracted to the sounds emanating from the speakers.

You do believe me, don't you?

Answer 4

So how does the fluctuation make the speaker coil move back and forth? The electromagnet is positioned in a constant magnetic field created by a permanent magnet. These two magnets -- the electromagnet and the permanent magnet -- interact with each other as any two magnets do. The positive end of the electromagnet is attracted to the negative pole of the permanent magnetic field, and the negative pole of the electromagnet is repelled by the permanent magnet's negative pole. When the electromagnet's polar orientation switches, so does the direction of repulsion and attraction. In this way, the alternating current constantly reverses the magnetic forces between the voice coil and the permanent magnet. This pushes the coil back and forth rapidly, like a piston.

read the rest (and see a demo) at the link below.

good luck!