How long does it take a subwoofers magnet to lose power? And about how much potential difference/SPL loss can it make?

I ask because our 3rd sub is now built and zapped and on its way today, I think the builder seems to think that the new sub will be better than our other two because of the fresh magnetizing.

The others were done last year. Should I magnetize the other two also to make them all fresh, or will the difference not really be noticable?

 

it should be fine

 

probably longer than your interest in SPL, it takes a long time

I have never heard of this thing you speak of... I have a fair background in Neo magnets (electron energy) and have worked on motor development in electrical motors with a couple companies (Moog, DR, DRS, Parker, Danaher, etc.) and I have never heard anyone talk about zapping, or re-magnetizing a fixed natural or rare earth magnet

 

Me neither.. I was thinking maybe because its an older magnet, since he recycles/builds with used sub parts and new recones.

Some of the magnets he uses could be 10 yrs old... old enough to lose power??

 

Where's he send them to be zapped?

 

Don't know bro. He's in the southern states though..
Particle accelerator electromagnet
NOT the one he uses..lol

 

money grab!

 

I could believe its a money grab, seeing how no one seems to think its useful(the zapping)
But I'm paying the same as my other subs cost and he never mentioned zapping them before..
He even mentioned needing an appointment to zap it!!

So I don't think its a extra cash thing
I may have to just suck up my self respect and ask why zap it...lol

 

Here's the true danger in all of this - all magnets have OEM spec's the important ones are the summary specs:

Maximum Energy Product (BHmax), measured in MegaGauss Oersted (MGOe). This is because the size and shape of a magnet and the material behind it (such as iron) have a large effect on the measured field strength at the surface, as does the exact location at which it measured.

Coercivity (Hc): This measures a magnet's resistance to demagnetization. It is the external magnetic field strength required to magnetize, de-magnetize or re-magnetize a material, also measured in Gauss or Tesla.

And I am quite certain that this data will not be available. Also, the magnet would have to be removed from the basket etc...

If your customer desires a tight tolerance between each driver - the only way to ensure it is to purchase all new drivers with sequential serial numbers.

I should also add that losses in the drivers suspension will be many-many time greater than any losses in the magnet - unless it was dropped.

 

No clue what you said dude.. but thanks for the info
I'll reread it in a few years