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View Full Version : Storage - back-to-back is crap-to-crap?



robertbartsch
06-07-2009, 02:30 AM
Ok, so I read on the Internet that storing two or more magnets in close proximity is a bad thing leading to deterioration of motor strength. Unfortinately, I can't find the article now but I thought it memntioned that a back-to-back oreintation was particularly bad.

So, is it wise when storing drivers that they should not be close to each
other?

What about storing them on a steel metal shelf; is that bad too?

ratitifb
06-07-2009, 06:33 AM
Ok, so I read on the Internet that storing two or more magnets in close proximity is a bad thing leading to deterioration of motor strength. Unfortinately, I can't find the article now but I thought it memntioned that a back-to-back oreintation was particularly bad.actually it's the bad way to stock but according to magnet suppliers recommendations ferrite magnets are fairly rugged regarding their resistance to be demagnetized except if you keep them near rare earth magnets. But when used with other ferrite magnets, there is little chance of demagnetizing them, even if you store them with North and North poles touching.


So, is it wise when storing drivers that they should not be close to each
other? Storing with North and Sud poles touching is OK (see coaxial drivers ;) for example)

Issued from some magnet supplier recommendations (regarding permanent magnets), the proper way to remove a driver when they are stacked in rows is to first separate each row from the adjacent row. To do this, the row should be pulled away directly, (do not slide one row down another row).

In order to isolate individual driver, the magnet should be pulled directly away from the next magnet. Do not slide the magnet in any way.

Basically, store your drivers separated by different types of magnets.


What about storing them on a steel metal shelf; is that bad too?NO since it's the recommended way to package magnets if you want to keep stray magnetic fields to a minimum during shipping process. The steel shelf is acting like a low resistance path (reluctance) for the magnetic field to from one driver to the other. Think of this as "shorting out" the magnet, but this does not damage the magnet in any way!

spkrman57
06-07-2009, 08:18 AM
I find it hard to keep the drivers magnets very far away due to my collection of drivers and lack of space to store them.

Here is just one place in my house with drivers laying around waiting for a project to use them in.

Ron

ratitifb
06-07-2009, 10:21 AM
fortunately, the stray magnetic fields of the drivers compared to coercive force of the magnet materials are generally low ... mainly with a good magnet motor design :p (gauss energy concentrated inside the air gap)

Mr. Widget
06-07-2009, 10:28 AM
Store your woofers vertically guys... for most woofers if you store them long enough face up or down they will sag. There are woofers with very light cones and stiff spiders that probably don't care how they are oriented, but for most woofers with moderate to low Fs, they should be kept as they would be mounted in a cabinet. If this is impractical, you can flip them every few months. I have done this in the past... I use the changing seasons as a guide, June 21, September 23, etc...

In general I try to keep the woofers in their original boxes until I use them. I then can keep them on edge... if you are going to store them for a number of years, you should rotate them, even if they are on edge... same for your mounted woofers if they are heavy coned low Fs designs.


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spkrman57
06-07-2009, 10:32 AM
I do rotate some of the drivers that would be suseptable to cone sag once a month.

A bigger house would be a nice remedy, just not happening....

Regards, Ron



Store your woofers vertically guys... for most woofers if you store them long enough face up or down they will sag. There are woofers with very light cones and stiff spiders that probably don't care how they are oriented, but for most woofers with moderate to low Fs, they should be kept as they would be mounted in a cabinet. If this is impractical, you can flip them every few months. I have done this in the past... I use the changing seasons as a guide, June 21, September 23, etc...

In general I try to keep the woofers in their original boxes until I use them. I then can keep them on edge... if you are going to store them for a number of years, you should rotate them, even if they are on edge... same for your mounted woofers if they are heavy coned low Fs designs.


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Mr. Widget
06-07-2009, 10:53 AM
A bigger house would be a nice remedy, just not happening....
Wouldn't it though!:)


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