Hi

I have the following 2 speakers:

They are 11cm in diameter, and have quite big magnets.

In the image, you see them side by side.

If I store them face to face, like this:

can it harm their magnets?


I ask this, because when 2 speakers are adjacent face to face, their magnets have similar polarity facing one another.
Add to that the fact that they have 0cm distance between them,
it makes me fear that maybe they can weaken each other's magnet..

Can that actually happen?

 

I don't think so.
Speaker magnets are built so their magnetic field is focused in a thin gap in the center, where the voice coil is.
Here's a reality test: As you move the speakers toward each other, do you feel any push or pull?
No?
Then the magnets are not interacting with each other to any useful degree.

 

Hi #12

Thank you for your reply

I don't think so.
Speaker magnets are built so their magnetic field is focused in a thin gap in the center, where the voice coil is.

Well, definitely sounds logic.
However If we take a small iron nail or pin, and put it close to the speaker, it will be pulled.
So while ideally the magnetic force should be focussed only on the internal voice coil,
in reality the magnetic force also spreads out, out of the area where it is needed to perform its action..
(I assume that's why the term "magnetically shielded" exists, to note that the magnetic force doesn't go out of the speaker box..)

So to summarize, I don't know how much can we trust this fact, for the problem I describe..

Here's a reality test:
As you move the speakers toward each other, do you feel any push or pull?
No?
Then the magnets are not interacting with each other to any useful degree.

That's actually a good idea, which I performed before I put them like that.

I put them face to face, 0cm distance between them, and moved one of them to the sides
(so the distance between them remains 0cm, but the magnet location of one of them changes, to see If I feel anything)

Happily, I found that there is no felt force while moving the moving speaker.

I emphasize the word "felt", because the fact that there is no felt force, doesn't mean there is no force..
It is more likely, that it means that there is a force, but it is below the level that causes movement or repulsion to happen.

So in short,
from both these good points that you raised, I think it is still hard to conclude that they are safe to be stored like that for the long term.


Maybe you or anyone else have another idea/opinion?

Thank you to anyone that can contribute

 

Modern magnets are not easily demagnetized.
Even if there were a noticeable force between them when stored, it would likely have no significant effect on the stability of the magnets.
If magnets are stored so the opposite poles are in contact (attracting each other) it will actually help stabilize the magnets.
That's why some magnets are stored with a keeper across their poles, to provide an easy path for the magnetic field and minimize he weakening of the magnet with time.

 

If magnets are stored so the opposite poles are in contact (attracting each other) it will actually help stabilize the magnets.

Yes but here the case is exactly the opposite:
They are stored with identical poles close to each other (tho not in actual contact)

 

If the magnetic fields were strong enough to interfere with each other, you wouldn't be able to get/keep them close together.

 

I agree. Storing them face-to-face ensures a minimum distance that is too far apart to be a concern. Storing them butt-to-butt could be a potentially bad practice since they should repel each other in that configuration, and would be much closer.

But, I suspect the field strength needed to degrade a modern magnet in any significant manner is a lot higher than the puny field of a similar magnet nearby, no matter how close. Think of the permanent magnets in an PM alternator. Because of the loading on the stator coils, and the opposing magnetic field that induces, the rotating magnets see an opposing magnetic field, day in and day out. They last a long time and I don't think they fail due to weakening magnets. (Unless they get really hot.)

 

Or for that mater the magnets in a small PM motor.

 

Yes but here the case is exactly the opposite:
They are stored with identical poles close to each other (tho not in actual contact)

Do you have an example of a speaker with a weakened magnetic field that causes you to worry? Or, is your life so perfect that you are now inventing things to worry about?

 

Do you have an example of a speaker with a weakened magnetic field that causes you to worry? Or, is your life so perfect that you are now inventing things to worry about?

OCD is the mother of unnecessary invention.

 

Think of the permanent magnets in an PM alternator.

Or for that mater the magnets in a small PM motor.

I see..
Good point.

I also never encountered a PM motor that got its magnets weakened.
(which is surprising, because the coils indeed induce an identical polarity on the magnets, and they also move.. yet the problem never happens)


OK in that case I will store them face-to-face, but not back-to-back.

Thank you all

 

I see..
Good point.

OK in that case I will store them face-to-face, but not back-to-back.

Thank you all

Good idea. Maybe you can keep them oriented east/west during storage so the earth's magnetic North Pole doesn't demagnetize them.

 

A better advice would be to recommend me to build a magnetic shielding box, no?

 

A better advice would be to recommend me to build a magnetic shielding box, no?

Here you go. Magnetic shielding that may work well for you...

 

I was worried more about my speakers than about myself

 

If I store them face to face, like this:

can it harm their magnets?

No.