Tutorial - How To Recone A Speaker
Posted 21 June 2005 - 11:39 AM
Here's the quick and easy way to recone speakers.
First you'll need:
- A Stanley knife (to remove the old cone/coil)
- A scribe (very handy, you'll find ways to use it)
- A small flat screw drive
- Soldering iron & solder
Then onto the reconing goodies:
What you see is a complete recone kit. This consists of:
1x Coil, former & spider assembly
1x Cone & surround assembly
1x Dust cap
1x Lock Ring (this is particular to this kit and secures the spiders to the basket)
We're using Loctite Prism 480 adhesive. Its specially designed for high pressure, high temperature bonding of rubbers, alloys & canvas, and dried without residue. Perfect for our application ! Fully cured, it will withstand 22PSI of strain.
Quick adhesive notes:
Dont use an epoxy, they can't be easily removed at a later date if you need to recone again.
Superglues will leave a white residue thanks to the curing accelerators in them, and they can attack foam surrounds.
Silicon based adhesives dont have a high enough bond strength
Finally there are the gap spacers (the white plastic C's), these center the coil in the motor while the adhesive sets. Without them, it's almost impossible to get a good clearance and you'd end up with binding.
Mine were supplied with the reconing kits, but you might not get them with yours. As an alternative, you can experiment with heavy thickness paper instead to get the gap right. The pole piece should be a snug fit inside the former with the sleeves in place.
Here's a close up of the coil:
Duel voice coil, flat copper wire, 2.5" alloy former with Kevlar wrap. 1ohm a piece.
Duel spiders, formed and sealed in the factory with tinsel leads between the spider layers.
This setup should be good for 3000W burps.
Posted 21 June 2005 - 11:40 AM
Here's the motor & basket with everything removed, ready for cleaning up. Note the AUS written on the pole piece.. this sub was hand built in the US for export here.
A good scrub down with Acetone has the old glue and daggy bits removed. A good clean surface is essential for a good strong bond !
Prism 480 has been applied to the basket ready to bond the spiders.
With the spacers inside the former, slowly slide the former (with spacers inside) over the pole piece. Its a snug fit to ensure a perfect gap, so be gentle. You dont want to damage anything.
The Prism 480 is a fast setting glue, so the spider is already starting to bond to the basket ! To fit the locking rings, I've punched guide holes in the spiders using a scribe. Then add another healthy dose of 480, lay down the lock rings and screw everything down firmly. Spiders & coil are DONE !
Posted 21 June 2005 - 11:40 AM
Then insert your new leads, hit it with a soldering iron and some solder. Easy.
The finished soldering job, nice and clean.
Posted 21 June 2005 - 11:41 AM
Simply slide the hole in the center of the cone over the former and snug it down against the spiders. When properly seated, the outer edge of the surround will sit flat against the basket. This step requires some gentle coaxing, its a VERY snug fit.
Once its in position, apply a generous amount of 480 to bond the cone to the former & spider.
Getting close to finished now ! Applying Prism 480 around the edge of the basket to stick down the surround. Apply an even layer, gently lower the surround onto the adhesive. To ensure a good bond, I sat a book ontop to gently push the surrounds edge down onto the basket.
All done. Spider, former & cone are bonded. Surround edge to frame is bonded. NOW you can clide out the spacers from between the former & pole piece (finally).
Some 480 around the edge of the dustcap, center it, stick it down and put a bead of it between the edge of the dust cap & the cone for a good strong bond. I then sat a jar of peanut butter on the cap to hold it down while the Prism set.
Posted 21 June 2005 - 11:48 AM
Q. Can I use other adhesives ?
A. Sure thing. Loctite has a huge range of speaker specific adhesives you can use, they even have an indepth speaker building article on their website www.loctite.com
I used Loctite because its what I could get, other brands such as 3M can be used with success.
Q. My speaker manufacturer says I need special glues only they make, is that true ?
A. They simply liscence adhesive technology from companies like Loctite & 3M. They're speaker manufacturers, not chemical industry ! Some will void your warranty for using "other" glues, but they'll void it for DIY reconing anyway so dont stress.
Q. Is this hard to do ? I dont think I could do it.
A. This is very easy. Infact, this tutorial is my FIRST EVER RECONE ! Thats damned easy.
Q. Do I need the specific recone kit for my subs ?
A. YES. Dont mess around, get the correct recone kit for your specific speaker otherwise you're in for grief.
Q. Isn't it bad to have your daughter play drums on the subs ?
A. Probably, but she's so cute when she does it.
Q. What subs are those ?
A. Atomic Apocolypse 10". 1ohm copper DVC, double hard spiders. They're built for SPL.
Q. Where did you get the recone kit ?
A. From the Australian Atomic importer.
Q. Where did you get the Prism 480 ? Bunnings doesnt sell it !
A. I called Loctites head office on their 1800 number, they gave me the name & address of my local distributer who happens to keep a supply of Prism 480 for industrial clients who use it in heavy factory machinery !
Posted 12 July 2005 - 10:51 AM