motor question

[blowthemup 10+ year member]

How hard would it be to mess up a motor or burn it up through abuse or bad enclosure? I assume your coil would go before your motor would be damaged but i'm not sure how all that works.

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[big scott]

motors normally dont got bad.

its the cones that go, well voice coils.

now if you drop a sub you could shift the motor, or crack it.

 

[blowthemup 10+ year member]

What exactly does a motor consist of? I know theres a magnet envolved somehow lol

 

[ciaonzo 5,000+ posts]

The motor is technically the coil and magnet as a system. Just like any other DC motor (but not AC induction motors), it has permanent magnets that set up a static flux field and then a coil that, when you apply current to it, becomes another magnet (electromagnet). The two repel and attract as the DC current from the amplifier alternates from the positive half of the musical waveform to negative. This moves the cone in and out.

Heat will destroy a coil winding but it will also reduce the charge of a neodymium magnet if the temp is too high for too long. I don't believe the same is true for ceramic and cobalt type magnets.

 

[hispls 5,000+ posts]

What exactly does a motor consist of? I know theres a magnet envolved somehow lol

It's basically a big horseshoe magnet with the N and S poles very close to each other at the "gap".

Typically you've got a top plate, bottom plate, pole piece + your actual fixed magnet of ceramic or rare earth. As others said, apart from dropping it, baking it in the oven, or trying to over-charge it there's really not much you can do to hurt it.

 

[hispls 5,000+ posts]

but it will also reduce the charge of a neodymium magnet if the temp is too high for too long. I don't believe the same is true for ceramic and cobalt type magnets.

Thilo claimed that neodymium magnets losing charge in loudspeaker applications due to heat was a myth. I have been also calling bullshit on this and have yet to see anybody offer any proof to the contrary. Rumor, myth, and urban legend only.

That said, you can check magnet supplier websites for data sheets on how much heat degrades fixed magnets of varying materials.

 

[ciaonzo 5,000+ posts]

Thilo claimed that neodymium magnets losing charge in loudspeaker applications due to heat was a myth. I have been also calling bullshit on this and have yet to see anybody offer any proof to the contrary. Rumor, myth, and urban legend only.
That said, you can check magnet supplier websites for data sheets on how much heat degrades fixed magnets of varying materials.

That's actually great to hear, it always bothered me that it was possible. Thanks offering a different viewpoint.

 

[hispls 5,000+ posts]

That's actually great to hear, it always bothered me that it was possible. Thanks offering a different viewpoint.

Audiopulse » Myths About Subwoofers

Worth the space in your bookmarks ^^^^^

 

[blowthemup 10+ year member]

Thanks guys!

 

[mrflamboynt]

Yup can't burn-up a motor (magnet side) from regular speaker use, even if it's abusive. Also speakers operate on AC power.

P.S.

Neodymium may lose BL as heat increases (regarding speaker application) but it's not permanent. It's magnetic properties return with respective temperature.

Adire Audio Parthenon is the closest thing to a high-performance transducer which employed neodymium. How ever it never went beyond prototype phase. The (neo) magnets were staged far enough from the coil, to keep heat away.

Good luck

 

[adulbrich 5,000+ posts]

Yup can't burn-up a motor (magnet side) from regular speaker use, even if it's abusive. Also speakers operate on AC power.
P.S.

Neodymium may lose BL as heat increases (regarding speaker application) but it's not permanent. It's magnetic properties return with respective temperature.

Adire Audio Parthenon is the closest thing to a high-performance transducer which employed neodymium. How ever it never went beyond prototype phase. The (neo) magnets were staged far enough from the coil, to keep heat away.

Good luck

Toss a magnet in a bonfire and see if it returns to being magnetic after it cools off.

*spoiler alert*

It doesn't //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[The Camry]

Toss a magnet in a bonfire and see if it returns to being magnetic after it cools off.

*spoiler alert*

It doesn't //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

What causes this anyway

 

[adulbrich 5,000+ posts]

What causes this anyway

Poles aren't lined up anymore, so there's not a definite North and South pole anymore.

Poles of the atoms are normally lined up in things that are magnetic. Heat jumbles them up

 

[mrflamboynt]

Toss a magnet in a bonfire and see if it returns to being magnetic after it cools off.

*spoiler alert*

It doesn't //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

You're drunk. Pretty sure my reply references SPEAKER APPLICATIONS. No mention of bon-fires.

 

[mrflamboynt]

When it comes to SPEAKER APPLICATIONS a temporary rise in heat can cause a temporary decrease of magnetic energy. Ceramic magnets seem to perform better than neodymium when exposed to heat.

Google search "adire parthenon"... The creator of it (parthenon with a 24"x 24" baffle) claimed to move as much air as 10 18" subs, accurately.