Advice on DIY voice coil replacement

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I have a 15" 1000W subwoofer driver with a perfect rubber surround, cone diaphragm, duct cap and a *very* heavy and large magnet. Unfortunately, this has a burnt voice coil (zero ohms across the terminals and a lot of friction when tried to be gently pushed in/out).

Now, I have replaced surrounds on several speakers - but am yet to get into the big league and try replacing a voice coil :)

Can this be done as a DIY? Has anyone done this sucessfully and could offer me advice? I could only locate MAT Electronics as a source for replacement voice coils.

Thanks
Mayank
 
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Hi Mayank,

I would contact the manufacturer for a recone kit. If that's not available you might want to look for an aftermarket cone but you will need someone with enough knowledge to get you a decent replacement.

If there is significant damage inside, around the magnet and pole piece, then sometimes it's just too tough to clean out the nasties and you'll have to start with a new driver.

Yes you can do a recone yourself but I recommend you watch someone do it first.
 
Hi,
I have a similar problem.

I think the driver must have been dropped and the magnet became detached and squashed the VC and former.

I became disillusioned at the prices retailers were charging for re-cone kits, VC & formers, leadout wires.

It seemed to be uneconomic to save my 18inch driver, but I'm still living in hope.

Awaiting responses from others.
 
Hi Mayank, Andrew T,

"Can this be done as a DIY? Has anyone done this sucessfully and could offer me advice? I could only locate MAT Electronics as a source for replacement voice coils. "

If you can source the voice coil that would match your burn one, so much the better.

I have seen someone did it and I knew after that I could do better and so I did try on some speaker that are destined to the dust bin.
Remove the old coil by cutting through the dust cap,cone and spider, you will need to cut it with a sharp blade with great care as you need them as close as possible as you need them to glue back to the new voice coil former.
Place the new coil in place of the old one. place some sim between the pole piece and the voice coil former, I use some strip of bond paper on four side to hold the coil in the center of the pole piece, once centered and firmly in place glue the former to the spider and the cone, when dry remove the sim and check that the cone is free of any rubbing on the pole piece and the yoke by pushing the cone in and out, measure the coil for resistance, if not use a 1.5V penlight battery to check the speaker if you hear / see the cone move, then place back the dust cup, you just revive a dead speaker.

I hope that help.

This is DIY so do this is on your own risk.

This is assuming that the yoke and the pole piece is clean and free of any debris. If your ambitious you can wind the coil yourself
I did it once as a practice run and it work. After this I did a couple or reconing while reuse the original voice coil on a kapton former using the same process mention above.

cheers
unmibh
 
Hi Andrew,

I use what ever glue is available to me at that time which is Elmers Glue, and some rubber cement. I use elmers Glue to hold the voice coil in place and this may not be the best to use but it did hold, later on I was told by a friend of mine that using epoxy ( the one where you mixed two part ) was better that it will also hold on at higher temp, all you need was to wipe a thin coat on the coil to hold them together.
Insulating varnish that is used on transformer will work too if you have them.
For the spyder and cone I use rubber cement and for the dust cap elmers glue since they will turn clear when dry and will retain the clean look.
I only did a two layer as making 4 layer wont do as the gap between the pole piece and yoke is small. I use wire from old transformer, since that was just a trial run, It all work out OK for me.
I think speaker glue are now readily available.

Practice first is what I could advice. Its really quite easy and can be done.

Good luck and I hope this help.

Cheers
unmibh
 
I am motivated to attempt this!

Here is what I have done/found out so far:

[ppcblaster] Thanks for referring the reconer repair shop listings. I called a few of them (they were all extremely courteous) and got quotes between $105-$160 to replace the voice coils for this speaker. In addition, shipping charges for this 28 lb speaker (both ways) would add another $80-$100.

[cal] I contacted the "manufacturer" (Definitive Technology); they do not stock or sell recone kits but offered to send me a replacement driver. I think this could be because they are using speakers from an OEM supplier. I could not identify the original manufacturer from the label which is as under:

0676A100 151569 75 OHM
67-98380033 G3

I am trying to locate aftermarket voice coils and spiders (only one I found who will sell 1 or 2 pieces is MAT Electronics). There doesn't seem to be any damage inside around the magnet - but I will confirm that once I remove the cone.

[unmibh] I hope the replacement voice coil will work. Thanks for your instructions (I believe these are the *only* ones found anywhere! Question - did you cut through the dust cap, cone and spider while the cone and surround was attached to the frame or did you seperate the cone first? I hope it is the former.

[andrewt] I found a page on an adhesive manufacturer's website with details of different types of glues for spiders and cones. Good ponters on the process as well, including that for kapton:

http://www.hernonmfg.com/speakerass.htm

I am off to attempt to do this next weekend. Wish me luck :)
 
help...

Hi everyone, I am new in this site and I am trying ro recoil some of my friend's speakers, can someone refer to me a good place to obtain just the voice coils?

FYI "tinsel" is the spanish word for "dressing leads" between the connectors and the coil wires.

and a "dust cap" is the piece right in the middle of the cone (a dome).

Thanks in advance and I found useful information here.
 
I've done a bunch with purchased re-cone kits. If you can get a re-cone kit it is rather easy for an accomplished DIY'r..

The glue in the kits looked very simular to Weldbond. After trying Weldbond on numerous surrounds, I've found it works extreamly well and dries clear..
 
If we can remove the full cone coil set with minimum damage, it is better.
Then we can replace any component as required.
This is either done with chemicals or heat.
To remove surround, it is with chemical like iso or
acetone(not suitable for some material including foam).
If the speaker is not very old then we can use hotair gun to loosen the adhesive & slowly remove it.
Many people use infrared bulb for heating purpose.
Similarly we can remove dust cap & spider.
i know few people do this but very time consuming.
They keep the full kit handy if required.
 
Been there, done that, would'nt go again!

Hi, had an unamed 12", back in 1992. I unbolted the magnet and took the old winding off counting the turns as I went. Put some normal copper wire of similar thickness, smeared some glue on the former and began winding. Even with four bolts for reallignment, it was hard getting the former and coil central.

After, it distorted at low volume, but given some welly, the dead driver boomed again.

when you have the magnet dissassembled, shove some card in the voice coil cap, to keep the crap out. You could tape it up, but I used the card, because I could wipe around the gap, if you like, to clean out any molten varnish from melt down. Remeber its a magnet, so when you unbolt your basket from the magnet, if the bolts were tight, as in my case, some meatal fragments came off and got attracted near the gap.

Sometimes, no bolts are available, you have to cut through the diaphram underneath the cone, allignment is always crucial. PVA is a godsend. Sellotape will hold your coil when you want a rest. Put aside 3 or 4 hours to do this. Be in a good frame of mind, you can easily get P'*ed off with it, don't have anyone bother you.

Its a good challenge and I think ALLIGNMENT is the major concern.

Goodluck:)

Fuzzymuff
 
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