What is the best way to repair a speaker cone? I have an amp that I'm trying to sell, but I noticed a fairly small puncture in the cone (see picture).
I've read something (I think on this forum) about soaking a coffee filter or paper towel in wood glue to act as a sort of patch. Is that still the best way or is there something better to do?
Thanks!
If something I wrote can be interpreted two ways, and one of the ways makes you sad or angry, I meant the other one.
I repaired a couple by using wood glue and a paper towel single ply. Do both sides. Afterwards sprayed with flat black paint. Check out some YouTube videos on the subject.
Glue and tissue will certainly work.. Personally, I use black RTV silicone.. Plain old black auto repair stuff.. Smooth the original paper back in shape as best you can, and apply the black RTV over the tear.... let it sit a day.. It will never break around that spot again, and the speaker will sound as good as it ever did,, Over many decades, I have used black RTV on speaker rips and tears, and its always worked perfectly for me... bob
I'm over the hill and hittin'rocks on the way down!
no gear list for me.. you don't have the time......
Same as Bob C. Here's a shot of one I repaired with RTV. A dumb move trying to pick it up by the rim and it rolled around on my knuckles due to the weight.
I repaired it with RTV and it sounds fine. It's been like this for 5 or 6 years and I can't hear any difference. I didn't bother to paint over it. Unsightly yeah, but my concern is with the sound.
That rip in the speaker will certainly decrease the value of the amp.
I don't know what amp you are trying to sell but if it is a valuable amp I would suggest you recone the speaker.
Erv
Fortunately it's not a valuable amp. It's a Yamaha DG80-112. It's pretty cool in that it has motorized pots that move to the preset positions. Somebody gave it to me because I thought I'd use it, but I never did and I just want to get rid of it.
I hope to get $400 for it, and I might be a little over-optimistic at even that price. Hopefully if I repair the cone and clean the speaker grille a little bit.
If something I wrote can be interpreted two ways, and one of the ways makes you sad or angry, I meant the other one.
What Bob said is what I've used for decades. I even repaired a 15" JBL that had the suspension ring torn almost all the way around. I coated the ring with black silicone RTV, then cut a strip of thin nylon fabric and laid it into the suspension ring, working it into the grooves with a dull pencil. Then I overcoated the repair again lightly with the RTV. I played that speaker for about another two years, and finally the voice coil blew (from playing too loud with a fuzztone).
If you can't find some black RTV, "Shoe-Goo" will work, too.
Anything you use on a speaker cone to repair damage will affect the tone. The cone will have a different weight and will not vibrate/oscillate evenly. The bigger the repair the more it won't sound the same.
I've repaired a few speaker cones and always been dissatisfied with the results.
Paul Sutherland wrote:Anything you use on a speaker cone to repair damage will affect the tone. The cone will have a different weight and will not vibrate/oscillate evenly. The bigger the repair the more it won't sound the same.
I've repaired a few speaker cones and always been dissatisfied with the results.
That's too bad. I think I'm still going to do it just because I want this amp out of my life and out of my living space, and I guess I need to put in a little more work to make this happen.
If something I wrote can be interpreted two ways, and one of the ways makes you sad or angry, I meant the other one.
Very cool! I've always thought that vintage speaker and pickup repairs are one of the most practical applications of the Ship of Theseus thought experiment.
If something I wrote can be interpreted two ways, and one of the ways makes you sad or angry, I meant the other one.
Like Larry Dering, I cut a patch out of a paper towel, then split it into two plies. Dilute white glue about 20%, then use an artist's brush to paint a thin layer around the hole. Apply one patch, then paint more glue over the patch. Turn the speaker over and repeat the same procedure on the other side. Let dry, then paint if desired. Have done several this way, they sounded fine and never gave any future trouble.
Last edited by Thomas Stone on 28 Jan 2020 3:41 pm, edited 1 time in total.
I'm grateful for this thread. I was just about to do the paper & Elmers patch that I've known of for years -- first heard of it via Ted Weber and I have confidence in it. But I much prefer the idea of RTV silicone and that's what I'm going to do.
I also need to paint/dope the surround where it got very frayed and weakened when it stuck to the baffle when I pulled the speakers. I'm going to use brushable roof patching sort of stuff -- liquid rubber, I guess. I didn't just pull that idea out of thin air -- did a bit of research and found this to be a popular solution.
In my early days, I repaired some damaged speakers using ADOS contact adhesive as it remains flexible (like RTV). I never noticed any issues, but back then everything was distorted anyway!
I feel that a wood glue would stiffen up the cone and eventually cause further damage.
01'Zumsteel D10 9+9; Sho Bud D10 SuperPro; 6 String Lap Steel (Homemade); Peavey Nashville 1000; Fender Deluxe 85;
1968 Gibson SG; Taylor 710 CE; Encore Tele Copy; Peterson Tuner; HIWATT T40 C 40W/20W Combo
If anyone is afraid of the RTV/liquid rubber fix, there are a LOT of speakers out there that come new from the factory with a rubber coating of some sort right around the ridges in the speaker paper where they attach to the frame.. Soaks right into the paper, and prevents fraying over time... RTV, or some sort of brush on rubber is the most common way to repair speakers these days, and in my opinion I don't think anyone will notice deterioration in the sound.... bob
I'm over the hill and hittin'rocks on the way down!
no gear list for me.. you don't have the time......
Stephen Cowell wrote:RTV is not what they dope the edges of the speaker with... it's something (like butyrate dope!) that will soak in.
I like carpenter glue and Yellow Pages for the flat part of the cone... I tend toward more flexible solutions on the surround.
Mostly... be careful when stabbing the speaker over the bolts! And removing it, of course.
Actually in my reply I said a "rubber coating of some sort".. never said RTV was used on new speakers. It isn't of course. However, it does work pretty well on repairs... bob
I'm over the hill and hittin'rocks on the way down!
no gear list for me.. you don't have the time......
You can buy a 3 oz. tube of automotive grade black rtv silicone at your home center for about $5 or less.
That's what I would recommend. I use the heavier ultra black oil resistant black Permatex but that's because I use it for other things too. It's costlier and heavier and dull in color while the other one is gloss.
Matthew Walton wrote:Thanks for the info y'all! When you mention RTV, is there something specific I need to get, or would any ol' 100% silicone caulk do the trick?
I would use black auto grade... bob
I'm over the hill and hittin'rocks on the way down!
no gear list for me.. you don't have the time......
Erv Niehaus wrote:I've reconed several JBL speakers.
I just did a 15" for a Fender Vibrasonic amp.
Erv
That's pretty cool. I need a coach
I picked up a JBL D130F speaker with fried, possibly melted voicecoil as the speaker doesn't move back and forth.. and also has a dried out damaged and punctured cone, It was used in a homemade PA system build by the seller for his band 50 years ago, and has been sitting on a shelf in his garage for 30.
Don't really know what to do with it, or if its possible to fix. But thought if I could recone it, I might see the $20 value out of it.
Is it possible to repair? Where to buy a kit?
Is this easy enough for me to do, or should I take it to a local speaker rebuilder?
