Speaker Cone Repair (missing section)

H

H.Huester

Active Member
Have been lurking for some time and finally got around to joining. There are some terrific people sharing incredible information on the board - I have certainly enjoyed reading and learning. As for my first post - I am looking for a little help in pointing me in the right direction. Many thanks for your help in advance!!!

I stumbled across a pair of AR9s in the corner of the local thrift shop. Already having of a pair of AR90s since the early 80s - I'm quite familiar with the AR sound. I'm going under the assumption that these AR9s may be worth fixing. Here is where I need some help!

They obviously need a hug - Cabinet, caps, etc. The part that I'm concerned about right now is that three of the four 12" woofers have sections of the cone eaten away by a rodent - all look like the one in the attached picture. It seems like the only options to fix these are to 1) recone the woofers, and 2) wait for original woofers to show up from somewhere.

Questions I have are:
1. Is there some source of AR speakers where I could get vintage replacements?
2. If I recone these woofers, will the sound signature really change enough to be noticeable seeing how these are woofers, versus tweeters/mid-range speakers?
3. If a recone is the best option, is there a recommended source of redone kits, or a good repair shop?
4. Can I remove the existing cone, and attach the cone from another AR 12" woofer to my existing voice coil? If so, will that change the sound as well?
5. Can I use the cone from another AR 12" speaker and patch in a section of that cone to replace the eaten away sections of these cones? I'm not concerned about aestetics - just quality of sound.

Again, thanks a MILLION for any help, and thank you to everyone for sharing their knowledge - I have learned a lot (spending countless evenings) reading through the various posts.

Sincerely, Heinz
 

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Start looking around on eBay for replacement drivers.

Replacement cones may be available. I'd probably do all four if you go that route.

GordonW is in the speaker repair business. You could send him a PM to see what he has to say.
 
Hey Heinz. Welcome to AK. Have a good time here.

On your question #5, I have done this kind of repair. Ugly, but it does work.

If you have a donor cone, cut the patch about 1/4" bigger, on all sides, so it overlaps the edges. Line up the foam edge part, so you can re-foam it. Aleen's craft glue works good on the patch. I try to attach the patch on the backside of the cone, when possible.

I've also used construction paper to make a patch. You can but it at any craft store, Staples, even WalMart has it. Just (sorta) match the thickness of the stock to the cone.

At least, this will give you some time to find intact drivers for replacement. Look on e-bay for the cheapest foam you can find. Remember, this is temporary, so don't put too much money into these drivers.

Have Fun
 
Cut the hole so there are only two straight lines, in a V (or better, L) shape. Then cut a thin cardboard (like from a frozen pizza box or something) piece in the exact same shape V/L with a rounded top so that the speaker gets a full, round cone, and glue it in with paper glue (don't forget to paint the cardboard first with black sharpie or something). Get some excess on the back of the cone so that it becomes firm.

Refoam the speaker.

It'll likely play as original. I've done this and did extensive comparing to the other speaker which was flawless. Zero difference in sound.
 
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Thank you VERY MUCH for everybody's advice!

I like the idea of using a heavy paper to fill the void and will give that a spin (followed by a refoam). It's a valid point that this could very well be a temporary fix until replacement woofers are found, or these are reconed, so I really have nothing to loose by trying. As far as being an ugly fix, that's really not a consideration - the music is what's important!

Thanks again for your help!
Sincerely, Heinz
 
H.Huester said:
Thank you VERY MUCH for everybody's advice!

I like the idea of using a heavy paper to fill the void and will give that a spin (followed by a refoam). It's a valid point that this could very well be a temporary fix until replacement woofers are found, or these are reconed, so I really have nothing to loose by trying. As far as being an ugly fix, that's really not a consideration - the music is what's important!

Thanks again for your help!
Sincerely, Heinz
Click to expand...

If you're gonna try the repair, I would caution the idea of using something heavy to patch in. Just use a donor cone piece, or construction paper. Those are the closest matches you'll get to the original makeup to the remaining cone.

Don't use any kind of heavy corrugated cardboard (like a pizza box), as it has layers. You want a single layer, otherwise it could buzz.

Don't worry about filling in the hole. It'll only add weight to the cone, something you want to keep to a minimum.

After you patch the cone from the back, you could brush a little glue on the patch seams, on the front of the cone. That will strengthen the patch and cone.

You want to get as close as possible to the cone material. Common sense applies here. Use your best judgement for the repair.

Good Luck
 
I'd prefer to try this with an old cone of the same make/vintage/weight. I really don't need that much material, so a damaged cone (with missing pieces or tears) would work well for this.

:scratch2: Hmm, just out of curiosity, does anyone happen to have a damaged (or beyond repair) AR9 woofer/cone "laying" around? :scratch2:

But if an old donor is not available, some hard paper (Canson paper?) or card stock will have to do. It is after all probably just a temp-fix (or maybe not, if it holds up).

I have also contacted GordonW as suggested earlier - he has graciously offered to evaluate and offer a possible repair method (am awaiting his return email).

Thanks everyone for your help!
Heinz
 
Gasket material (paper) comes in a number of thicknesses and might make a nice patch depending on the original cone material. Some cones are are hard and rigid, others heavier and thicker. Gasket material is rather dense and seems like it would be well damped.

The idea of using a sacrificial speaker cone of similar material is also a great idea. You can buy speaker cones from some online dealers.

MAT Electronics has a good selection and inexpensive prices.
http://www.matelectronics.com/cones/


Good luck,
John
 
While never repairing such a large missing section, I have repaired rips, tears and smaller missing sections. Black construction paper or coffee filters as a medium and diluted white Elmers school glue with a few drops of water. I thrifted a pair of Altec 872b speakers with the 420 biflex drivers. One of the drivers had a nasty rip and repairing via this method was the only feasible way to do it. They have since been moved to the garage, but still work great with the construction paper glue repair job. link to my thread with a few pics --> http://www.audiokarma.org/forums/showthread.php?t=599183
 
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