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Loose speaker magnets- HELP !!!

Started by LJN, March 07, 2016, 08:26:12 PM

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LJN

Hello, everyone. While out and about today, I happened upon a pair of 12-inch speakers from a Crate amp. They were going to throw them away, but gave them to me. After patching up some holes in the cones, they're still rattling and I discovered the magnets are each loose on one side. How can I fix this? Thanks in advance for any suggestions.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

J M Fahey

What does it mean:
Quotethe magnets are each loose on one side.
Post a couple pictures showing where.

Enzo

This^^^

If you mean the whole round magnet part is about to come off?  Or since it is a ceramic magnet no doubt, could the gray magnet itself be cracked in two?  In my book those make it beyond repair.  People like Juan who actually MAKE speakers, may have more insight than I.  But once you have to re-rivet the magnet to the frame, and the attendant need to center the voice coil in the gaps, you are well past the point of buying a new speaker in my mind.

LJN

Each net seems to be loose on only one side. Also, the baskets are slightly bent. If I can ever figure out how to post some pictures, I will. Thanks.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

Enzo

If the baskets are bent, good luck ever getting it all aligned again.

LJN

I actually managed to make them rattle a bit less, but it seems you're right.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

J M Fahey

You don't even imagine how much a couple pictures would help you.  ::)

LJN

Oh, trust me. I know they would help ALOT. There's just no way to get them on here.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

Enzo

Do your photos store in your computer?  If so, in what format (file extension)?

There are also photo sharing web sites you can post photos in, and put links here to view them there.

LJN

They're stored in my phone and I tried one of those sites, but my phone would still say either "low memory", or "cannot open file".
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

LJN

Here's what they look like. You may notice that one of them has a piece of paper under it's magnet. That seemed to reduce the rattling a bit.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

J M Fahey

Ok, although fuzzy, clear enough.
Magnet disk is joined to pressed steel frame by resistance soldered/welded "dots" .

Because of the huge thickness difference between magnet disk and frame  , often the welding is not very good and small cracks develop, which "travel" under vibration and may fully split/crack the joint.

What you hear today and if not taken care of, one day you'll hear a strong "thunk" and find the magnet loose in the bottom of the cabinet.

1) you need some epoxy.
Best is transparent (not crystal, one will be translucent light whitish cream colour, the other brownish like beer or honey), thick honey viscosity at room temperature, preferrably slow curing (3-4 hours to overnight) , 5 or 10 minute type will be too fast and silver coloured (aluminum powder filled) is and stays too thick.

2) set speakers face down on a table, warm/heat magnet and frame touching it with a hair dryer or heat gun, until it's quite hot to the touch but you can still touch it, that wilol be around 60C , convert to deg F at your convenience but hand-o-meter is universal.

3) mix , with a toothpick or even better a wooden brochette/skewer about one teaspoon each of epoxy components.

Better have some extra and junk it later than having to make a second batch, you might have not enough time because heat speeds things up.

4) with the wooden skewer (giant "toothpick") apply little bits of epoxy to the space between magnet and frame.

Metal temperature will partly melt Epoxy allowing you to push it into the "slit" all around, and being more liquid capillarity will suck it in, filling the space between frame and magnet which you can't actually reach.

Add as much as it will suck in, and with the remainder make a ring all around, which will also be partially sucked in, filling the void.

Let the speaker cool and dry overnight, magnet will be firmly held to the frame and buzz/vibration/play will be gone.

5) repeat on the other one.

as you see, reaching enough temperature to lower Epoxy viscosity is paramount,it will also "wet" surfaces better and much improve adhesion.

LJN

Cool! Thanks, Juan. I'll have to get some of that stuff. I don't actually have the speakers in a cab. They're still mounted to what was left of the front of the amp that they were in, which I wanted to build onto and make a new cab. Thanks again.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

J M Fahey

Oh, any reasonable hardware store should have it.
Ask for epoxy / transparent / slow hardening (hours) , not "minutes".

The trick is that heat makes it somewhat liquid and reach quite unaccessible places.

LJN

It's available at some of the local auto supply stores where I live. I think I know what you're talking about and I've used it a few times, but that's been a while back so I don't remember what I used it on.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL