12 replies to this topic

[Su8perkillr]

Hi guys, got a small question, I have a broken sound set, and I'm wanting to take it apart and use the electromagnet in the subwoofer to mess around. Is this possible by adding a simple energy source (battery)? Or is it linked to other systems?

[ΓΛPTΘΓ]

Broken speakers most likely is the voice coil came off the cone, either by overheating, totally melted, or just worked itself loose.

EDIT: Sorry, I think I miss read it. If you are trying to take the magnet out to play with it, the magnet are most likely to be a permanent magnet. And the voice coil is just a piece of wire coiled up and stuck to the cone.

Edited by ΓΛPTΘΓ, 25 January 2011 - 23:08.

[Su8perkillr]

Wait, how is a magnet in a speaker set permanent? I thought it was an electromagnet Well, Ill ask in science class as well...

[Chyros]

No, they tend to be permanent. Try it, just take it out and if it attracts without power, it's a permanent one.

[ΓΛPTΘΓ]

Su8perkillr, on 26 Jan 2011, 8:22, said:

Wait, how is a magnet in a speaker set permanent? I thought it was an electromagnet Well, Ill ask in science class as well...

The voice coil is what react to the signal input. As you pass current though a coil of wire, it will induce a magnetic field. Where it will interact with the magnetic field of the magnet. As the voice coil is fix to the cone, it will move it thus creating sound pressure wave. Which is what you hear.

You could call it a electromagnet, as it is really one but I don't think the output is enough to do much with it.

[Su8perkillr]

Hm ok. Im going to try it anyway, this set is broken and thus I have 5 speakers and a subwoofer to mess around with. Thanks anyway

[BeefJeRKy]

In essence, the voice cone is a very weak electromagnet in that the time varying electrical currents the coiled wire produce a magnetic field. But the magnetic field density of the permanent magnet should be a lot higher relatively and thus depending on the current variation (increase or decrease), the resultant magnetic field will either create an attractive or repulsive force. This vibrates the cone and produces sound as we hear.

[Su8perkillr]

Ok, my question was if its possible to highten the power of the magnet by adding a battery

[ΓΛPTΘΓ]

No, to put it simply. However if your speakers are decent enough, they might use high flux Neodymium magnets. Those are pretty damn strong if they are big enough.

[Su8perkillr]

Hehe Ok, thanks. Ill see

[Chyros]

ΓΛPTΘΓ, on 26 Jan 2011, 18:31, said:

No, to put it simply. However if your speakers are decent enough, they might use high flux Neodymium magnets. Those are pretty damn strong if they are big enough.

If the speakers would use neodymium magnets they would either be tiny or the speakers would launch themselves at the nearest magnetic object.

[ΓΛPTΘΓ]

While they are strong, but its not likely it will have that much of magnet to create such force...

Most of the time, they are used to save space, weight as well as having better performance on top. Just because they are stronger, not that they will not reduce the amount used to sensible level, it is a rather expensive thing as well too.

[BeefJeRKy]

It's true. Neodymium is often used in speaker magnets though Raptor pointed out, since low weight is an attractive quality.