Vintage Speaker Cone Renovation and Repair without Re-Coning
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- čas přidán 14. 05. 2013
- Old speakers wear out and must be refurbished when restoring the vintage guitar amplifiers, radios, and jukeboxes that utilize them. Re-coning is the best and most permanent method, but it has become expensive, parts are sometimes difficult to find, and the re-coned speaker will have to be broken in before it will sound as it should. In addition, preservation of the original cone is often desirable in the restoration of very rare amps and speaker cabinets. This video covers a quick, easy, inexpensive way to refurbish old speaker cones in your own workshop in a matter of hours. PLEASE NOTE: this method is not applicable to speakers with damaged voice coils. According to a viewer, this site offers all sorts of glues associated with speaker and coil construction, including the doping material used on surrounds: www.cpmoyen.com/
- Hudba
Here I am again with Uncle Doug, the man with all the answers! :) Out of all the DIY suggestions, this definitely makes the most sense addressing the needs. Thanks UD!
You're welcome, PM. Good luck.
I'm restoring a 1950 Wurlitzer Jukebox and your videos have been super-helpful, especially with the amp repair. I just followed you directions to fix up the speaker. I can hardly wait to hear the results! Thanks for the great posts.
You're welcome, Bob. I hope it sounds great !!
Well, I got it done and it sounds fairly good (for what it is -- a 70 year old system [Using a mono cobra pickup system]). Then it occured to me that some records which sound so bad, could be stereo 45's. And the system just can't phonically play them. Is that right? Your juke must be mono... and do you only play mono records? Thanks again!
Uncle Doug - 2 hours ago I had no idea who you were but this speaker lesson has been immense for me. I am interested in this stuf but know next to nothing. Thanks for the time you took to put this info together. Hopefully you do more "tutorial" vids. very cool.
You're welcome, Rob. I'm glad the video was helpful. I have posted about 109 other videos, so you still have a bunch more to watch :)
Thanks for taking the time for sharing your experience. I recently acquired a sweet pair of 1957 Jensen P10R speakers for use in an 18 watt, open back, guitar amp build. 1 is the ribbed cone and the other is a smooth cone. I had been contemplating on what, if any, product would be a good choice to "revive" instead of re-cone and wondered about the contact cement due to it being strong and very pliable. The old cones do dry out, become brittle and will almost certainly crack at higher volumes even if they have had low usage and been kept in a controlled environment. After watching your video I have decided to give it a try. It will be awhile before I have the amp ready, but I will post back with my results. Again, thanks for sharing!
You're very welcome, Chip. The procedure I describe doesn't work for all cones, but it really does improve most of them. I recently heard of a method using (a thin coat of) clear silicon caulking material to paint the suspension ring. I haven't tried it yet, but the speaker I saw with silicon repair looked and sounded quite good, and the silicon would be much stronger and probably more flexible than the contact cement. Thanks for your input and keep us posted on your results.
Uncle Doug I did consider Silicone as an option, but thought it may be a bit to heavy and have a negative effect on the reflex action. I think I may experiment a bit, with a less valuable speaker, with thinning out the Silicone to see if it will penetrate better into the dry paper. Just a thought :)
Give the thinned silicon a try, Chip, and let us know how it turns out. I have not had a speaker to experiment with in a while, and I definitely concur that experimentation should be done on less valuable speakers. In my experience, silicon really sticks to surfaces, so maybe penetration might not be necessary. Maybe just a very thin, surface coating (?)
.......and thanks for your inquiry and kind words. I really appreciate them.
The speakers I primarily intended the video for are the type used in guitar amplifiers, which just about always have one-piece, rather stiffly suspended cones. Hi Fi and stereo speakers, on the other hand, often have the foam suspension, which is much more pliable, and usually reside in sealed cabinets where trapped air restrains the cone excursion. Foam-suspended cones would probably not last long (or sound good) in an open-back guitar amp. Thanks you for your input.
Now that makes sense. Thank you.
You are one of my favorite Uncles.
Thanks, TL. You are one of our favorite nephews :)
Thanks very much, Doug. I had the speaker out of a 1947 GE radio with a substantial crack. Your method was quick, simple and effective. Thanks for sharing your time and talents in yet another excellent video.
You're welcome, Andrew. I'm glad it worked for you.
Doug, good job on the repair. I have made my own "dope" with a mixture of rubber cement and lacquer thinner. Not sure the exact mixture. I have an old turntable that I center the speaker and wet my brush and spin the turntable by hand. I can get a nice, even coating of "dope". I use a 1" artist brush.
Greetings, Bbend. I definitely agree with the idea of thinning the contact cement with lacquer thinner, it makes it easier to spread an even, penetrating coat. The spinning turn table is another excellent idea. Thanks for your input :)
I have done this too- very similar concept with great results.
Thanks for the tips guys. I am in old speaker repair mode (they've piled up and now I need 2 of them) :) No old turntable, but I have a 15" artist painting turntable that sure do the trick for consistent coverage and finish. Great tips all the way around and I happen to have all the needed material on hand. Thanks again!
This came in very handy for me, and my own experiences echo yours as far as materials, how to use and apply, where you need flexibility etc... One thing that I find very handy when applying anything to the surrounds or elsewhere inside the cone, is to have a turntable- I actually use a round ottoman (footstool) that spins, so I can use a brush to apply while spinning at a slow to medium speed to achieve a consistent and tidy application. One just has to be sure to mark or take careful note of the center spot to ensure it rotates properly and evenly. As always , thank you sir! I respect and appreciate your knowledge!
You're welcome, Jeff. Thanks for the excellent tip.
This works, Doug, but you have to make sure and get an even penetration around the entire surround. If you miss a spot or dont get it in the valleys, it will rip there at high volumes, or over time at medium volumes. Weldwood is a great product, and I have old Jensens that have been going for decades with this fix.
Also helps to thin out the cement with acetone. Helps it cover better, and pentrates the paper, actually becoming a part of it, so the surround acts like a butle-rubber surround!
Butyl?
I agree with all you say, Duncan. Thinning the cement is a good idea, especially if it's not a fresh can, as is the necessity of an even coat. Thanks for your input.
Thanks guys
Thank you very much, Uncle Doug! You have just helped me save one of my very rare, vintage speakers! And I am now a subscriber!
That's great to hear, Mike. Welcome aboard !!!
This is just fantastic. I subscribed a while ago and have learned much from your great videos. I have been sitting on an old, Celestion black back with a small tear just like the one in your speaker here. The second black back I have sounds fantastic and I have been very leary about getting this re coned as the materials are much different these days. I will definately try this to repair the old cone. Thanx so much for your great videos.
chaka9774 You're welcome, Chaka. I hope the repair works well for you.
Thanks for this video Doug. I just received a 1961 Danelectro Twin Fifteen amp and one of the two Utah speakers is beginning to separate along the speaker surround area. I will get me a tube of the black Permatex Ultra RTV silicone gasket maker stuff and carefully apply it to the tear. I dread the thought of re-coning these wonderful old speakers. The price for one but, knowing that the original tone will probably be lost forever with a new cone job. Perhaps I am wrong. Just seems to make logical sense that new paper will sound different than the vintage original cone material. Sad to say I have also got to reconstruct the mounting positions of the speakers. Even though this amp was well packaged in a 5/8" inch plywood crate with Styrofoam insulation all around it must have taken a hard slam and the speaker anchors pulled through the 1/8" Masonite mounting board. I've got some planning to do. Your channel is a great source to get tips for working on my aged trio of amps. Much appreciated.
It sounds like you have a challenging project, Kevin. I think it's always best to try to save the original cones, if possible. The silicon RTV gasket maker can bridge and repair most tears in the suspension (surround) portion of the cone, yet it maintains good flexibility. If your repairs work, then you have saved a great old speaker. If they don't, then you are no worse off than when you started. I'll bet you are successful.....best of luck :))
Cant thank you enough for doing all your video work, once our generation is gone all the knowledge is lost.
You're welcome, Shane :)
Thanks for the informative video. I also enjoy reading the comments & suggestions as a bonus. I recently purchased an old 15" Jensen to go into my magnatone project. The speaker is in dire need of TCL as well as some repair at two spots on the rim, very similar to the tears on your vid. Can't wait to try this repair technique.
You're welcome, PG. Yes, indeed, the viewer comments are a wonderful source of additional information......often extremely informative. Good luck with your speaker renovation.
Greetings, James, and thanks for your input. Do you have a video or Internet reference that explains how this is done?
Thanks again, CD, and good luck !!!
Thanks Doug,
Newby here. I appreciate you sharing your years of valuable experience.
You're welcome, Bob. I'm glad the videos are helpful :)
Ed, it's an automotive product and I bought my tube at Pep Boys. It's called Permatex Ultra Black RTV Silicone Gasket Maker. Be sure it dries thoroughly overnight and it will create a flexible, virtually indestructible repair. Thanks for the kind words....good luck.....and stay tuned for lots more videos.
hey there, you're almost rite, but i work in auto body, we use windshield urethane , and i have been using that so seal edges of speakers, that stuff is indestructable, but it sticks to everything, i mean everything ,,and only use a little bit,, put it in a bucket of hot water so it's easier to get out of the tube ( it's like a caulking tube )so be carefull
FYI,,,, the last time i ordered it , it was $ 10.00 , U.S. i've been using it for about 15 years and have no idea who makes it , but you can get it from any auto paint supply, you don't need special lisencing, wind shield adhesive,,, i also sealed my under mount sink in my kitchen with it, no hardware, indestructable
rejuvenating the suspension ring is a great way to keep you speakers running for years to come! rubber cement works pretty well! shoe goo is another one to help keep the suspension ring springy, great info here!
Thanks for the info, TK.
You have a Zenith 49cz852. A friend of mine discovered it and it is one of the nicest sounding speakers we've ever heard. He has a $1200 homemade tube amp that's been Finley tunes. I bought three of them and have yet to use them. If you have the motivation I would highly reccomemd using it with a tweeter with a 2uf capacitor on the tweeter. This speaker truly sounds amazing. My friend spent years with his 2 sons until they finally found this gem, the Zenith 49cz852.
Thanks for the info, Nick. I will treat the speaker with greater respect, now that I know more about it :)
Awesome tip! I was going through my stuff and was going to throw out a Eminince 12" because it had a tear in it (kids love to destroy any and all speakers!).....definately gonna try this.....and also re-vamp those 39 year old scorpions as well. Thanks a bazillion!
Ron Gay You're welcome, Ron. Rusty and I hope your speaker refurbishment is a big success :)
A great idea; I have used other methods, but yours is by far the better approach. The ridges of the speaker do create a challenge when it comes to restoring at a practical price.
+John Cunningham Thanks, John. This method isn't suitable for all speakers, but it does provide an quick, easy way for viewers to repair their own speakers at home. It may not work in every case, but I have found it to be quite effective, quite often. Thank you for your input.
i use that contact cement on all my split speakers..and have done it a long time...it works, and it stays flexible...nice video...
It really does work, Kenny. Thanks !!
Thanks for this tip, i'm very broke so this was invaluable.
You're welcome, SS. It's always wise to preserve vintage speakers....and our money....whenever possible :)
excellent tip I have done the same thing for 30 years with un cut
future floor wax sometimes painting the entire cone usually on equipment that was made before World War 2 thank you for sharing this tip and the RTV the silicone is excellent ...
I used your contact cement method with an old 6" speaker from an old radio.
No more flatulence of the speaker.
I'm glad it worked for you, F3.
I've been using silicone for years to repair/prolong the life of vintage speakers.
It is the best thing I've used so far, doesn't necessarily have to be black either.
Nice job, I've had to do that a few times with older speakers, especially some of the strange Philips "Inside out" ones that have the magnet at the front.
Thanks, RH. We're glad the video was helpful.
Best Tutorials about amps valves etc ever, thanks for the brilliant explanations of how things work.
Thanks, Brian.
@@UncleDoug i thank you kindly uncle.
@@briansweeney2419 You're welcome, Brian.
Greetings, CD. If you can gently move the cone inward and outward (by hand) without any rubbing of voice coil against the pole piece or magnet, I would simply repair the dust cap and continue to use the speaker. Even if dust or particles have gotten inside the voice coil area, causing it to rub, you can sometimes invert the speaker and gently blow them out. I only re-cone as a last resort, since it really changes the nature of the speaker, at least until it is completely broken in.
Another great video, thanks for these.
You're welcome, Davo. I'm glad you liked it :)
Thank you! Just tried the contact cement trick on some older Fender 12" that were flubby when cranked up and this worked like a charm!
That's great news, Cody. It's an easy fix that works fairly often.
Good job Doug. I learned this on another video by Glasslinger. I've used it on many speakers & can definitely hear the difference on the worse cases.
Thanks, Eugene. Glad it was helpful.
Awesome work unc, as usual.
Thanks, George :)
Thanks for this. I just gave 2 Celestion G12M's to a guy. I never noticed that one had some tiny rips around the edge in a couple of spots. I sent him this link so hopefully he can make it work/rescue it, and pays me for the speakers. :)
I have another one in a cabinet in the garage that sounds like it has a bit of a rip in it. I should take it out and see how bad it is. This might be the answer for that one as well.
Joe Foley Good luck with the repair, Joe. Let us know how it turns out.
Will do. Seems quite easy. Thanks for posting the video.
You're welcome :)
Thanks I repaired a paper edge speaker that was rip completely around the edge just had to center it and put the silicone on at 12-3-6-&9 o'clock allowed to dry over night then went all the way around, once that was dry I put the contact cement on the back side for added support, I did this because the contact cement will not adhere to the silicone. sounds as good as my good speaker and has been working daily for 3 weeks now.
Wow......that's a really drastic repair. I have never tried to repair a cone that had completely separated from the suspension. Good work.
Hi Doug,
I am lucky enough to have the former Harmon-Kardon speaker division's Lead Design-Engineer of 18 years owning and operating an electronics repair shop in my town. He told me that many companies used to use PVA for speaker assembly. This would be Elmer's glue, or even Titebond wood glue! He advised me to paint not only the surround, but the entire cone, and claimed that this was what some companies actually did "to give the speaker a perma-wet look", and I would assume to add stability over time.
I have tried this method for patching old drivers from radios and amps with great success. I am not sure about high volumes or extended periods of time, but it seems to maintain the rigidity of the paper and the tonal transfer without sacrificing anything. (For patching holes and tears with PVA, I simply use small pieces of cigarette rolling papers and paint on the glue, which is usually watered down ~5:1 - glue:water.
Great video! Thanks so much for doing what you do! I've been waiting for some time to be able to give back to you in some way after all you've taught me with your vids... Hope this helps!
Greetings, Britt, and thank you for your very helpful input. I would worry that Titebond glue may make the surround too stiff, but if this gentleman vouches for it, then I will definitely try it for my next speaker repair. I have successfully used glue of this sort with toilet paper as a matrix to bridge and reinforce tears in the cone, but must admit that cigarette paper would make a much neater repair. Thanks again for your excellent advice.
Uncle Doug
Hello, instead of Elmers PVA ,speaker reconers I know in the UK ( a rare breed here too now) use an EVA glue on surrounds, PVA is far more brittle than EVA glues with their additives of wax and resins. Looks like Elmers (OK on the cones) but is not the same and stays flexible.
Your contact stuff might well be the same stuff if its an emulsion, not spirit based.
I'd use a PVA to dope the cones or repair but use an EVA on the surrounds.
Good info, F3. Thanks so much for posting :)
festinger3 Hi! Thanks for the useful information F3. I am in the process of repairing some drivers and wanted to know if the EVA glue needs to be diluted with water before spreading it on the surrounds?
Regards.
Paul
You're welcome, Paul. I have never used EVA glue, so I'm not sure about dilution before use. Maybe you can find some info on the Internet. Good luck.
Thanks doug i will take a closer look!
Great channel!
I've been doing repair work for over 50 years and your suggestions on cone repair are all valid as are many of the suggestions from readers. I've used all of them. Have you ever replaced the flex leads from the speaker terminal strip to the cone? It can be done, but is very tricky to do since the braid acts like "solder wick" and sucks solder into it making it rigid. I'd be interested in hearing suggestions you may have if you've done that. I've had some success doing it over the years, but when the braid pulls free of the cone itself that gets really difficult. I've not done one for a long time, but one of these days another one will show up and I'd like some new ideas. I'm very impressed with your videos. Wish I'd had some of the knowledge you are offering in them years back when I had to learn by doing. I still love working on old vacuum tube equipment. Not many around that know how to do it these days.
+Paul H Greetings Paul, and thanks for your comments. I'm glad you enjoy the videos. I've had good luck soldering the silver braid over the years, but if you want to prevent it from wicking up the solder, then maybe attaching a heatsink clip (like you use when soldering heat sensitive components) to the braid would prevent wicking of the solder.
+Paul H I would like to hear more about your experience involving speaker pig tails (do and donts)
If by pigtails you mean the wiring connection between the speaker and amp, my main recommendation would be to provide strain relief between the wiring and the speaker terminals, i.e. a metal clamp to secure the wire soon after leaving the terminals, to prevent a snag of the wire from tearing the terminals (and possibly the silver braid) out of the speaker basket.....a condition I have seen and repaired rather often.
+Paul H I would have to test it, but I think if I painted small bands near the ends of the flex leads with something that soaked into the lead on the spot where it was put, it could stop or at least slow the solder from soaking further into the lead. Thus only the ends of the lead get solder on them.
Perhaps a little bit of PVA diluted in water would do the job.
Hi doug.. great videos! I have a 1965 jensen C8 in a tweed amp. I think it was an organ pull. the felt dust cap has pulled away and some of the cap is missing!
Probably need a recone :(
Uncle Doug, I'm a fly tyer and we use a product called softex, which is a very thin clear silicone based product. Thin enough to paint on, yet dries clear and flexible. I think it is made with chlorinated solvents cause it stinks to high heaven. But I'm going to try it on a Jensen 10" that needs to go to rehab. I'll let you know how it works out.
That product sounds perfect for cone reinforcement and repair, GA. One rule of thumb I have found is that the stinkiest and most toxic glues and repair materials always work the best. Please do let us know how it turns out.
+goanglingblues How did that go for you?
When I find old speakers whose cone is a bit weak around the edges I will usually apply a few coats of PVA glue to them. It absorbs well into the paper and does a very good job. I have a big bottle of the stuff (it's actually Pergo floor glue).
Thanks for the tip, D20 :)
Thanks for this tip Uncle Doug! I have just damaged a '66 Heppner speaker (from a Hammond) and hope to revive it.
Good luck, Chip.
What a great video and great advice! I love this sort of thing - there is so much you can do with relatively simple materials. I've never done this on a speaker before, but I've found in other projects that when spreading something like silicone with my finger, I can get a better and smoother spread with less silicone if I simply lick my fingertip before spreading it. This keeps the silicone from sticking as much and
I have a couple questions. First of all, has anyone considered warming the contact cement first? I'm wondering if this might help it to permeate the paper? Or maybe thinning it is best?
Secondly, does this change the sound characteristics of the speaker much? I'm thinking it might raise the resonant frequency. I have just recently purchased a beautiful old Philips Capella radio with 800 ohm AD3800AM speakers in it. These radios and speakers are legendary for their clarity, but it's over 50 years old. The speakers are in good shape now, but I'm thinking now might be the time to take some steps to ensure they stay good for another 50. I've read articles about people cutting the paper surround and replacing it with foam (Audiofriends sells them), but that seems a little drastic. I would much rather preserve the paper already there, but want to change the characteristics of the speaker as little as possible.
Greetings and thanks, Kurt. Heating the contact cement does indeed thin its consistency and improve its penetration into the paper. I only apply the contact cement to speakers with weakened/worn cone surrounds and it does brighten them up a bit, reducing the tendency to "flub" and noticeably improving sound clarity. Re your radio speakers, if they are functioning well, then I probably would not recommend any rejuvenation procedures. I'm a firm believer in not fixing what isn't broken. If they get a little "flubby" after a few years, maybe then......but that's just my (very conservative) opinion. Being involved only with vintage guitar tube amps, I have no use for, or experience with, foam surrounds. The only place I have encountered them is in speakers within sealed HiFi cabinets, where the enclosed-air back pressure limits their excursion. Best of luck with your Philips radio and other projects :)
Nice video, thanks for the tip.
You're welcome, BH. Regards to the handsome pup in your photo.
Some years ago I had a pair of Cerwin Vega home audio speakers that needed new foam surrounds. I hunted around online and eventually found an outfit called parts-express.com and ordered new surrounds from them. Like I say it has been a while now, but I remember thinking at the time that the price was reasonable. They sent me two 12" surround kits. The kit consisted of the foam surrounds, some plastic shims to shim the voice coil with while you get the surrounds on just right, new voice coil dust caps, the correct glue or dope to use, maybe a half dozen or so little foam swabs to spread the dope with and some very detailed directions. They also had a video on how to do it on their website. I remember thinking I was going to have to shell out for a new pair of speakers and found the surround kits to be boon by comparison. At first, I was a little intimidated by the thought of doing that sort of a repair myself since I not only never did one before, but I'd never even seen it done. But I just followed the directions and my speakers were good as new and are still in service today. They also had total reconing kits, mounting gaskets and pretty much everything else you can think of.
They sound like an excellent source of re-coning materials, DE. I too have found a really nice source of speaker supplies: The Speaker Exchange reconingspeakers.com/ Thanks for sharing your successful reconing experiences with us.
This is so ironic I can't believe it. I'm a mechanic and a true believer in Ultra Black. I was told you cant do that. I did. It worked. The one thing that made sense to me to repair outer portions of a paper speaker was contact cement. That worked to. I just bought an extremely rare paper speaker with a humungous square magnet. Finding a recone for these...probably not gonna happen. So i wanted to see what i could do. Damage is minor. And i found this which confirms that what originally worked will work again with buying something I have to make 24 monthly payments on with a down payment. Thank you. Good information.
You're welcome, Steve. Glad it was helpful :)
Brilliant technique!
Thanks, Sharky :)
Thank you for this great video!
+SiliconSet You're welcome, SS :)
Thats a great way to save some money and get more mileage out of old speakers. I have used nail polish to good effect on small imperfections or cracks in the past, but it has its limits.
+John Miner It will work with most speakers, John, but, of course, has its limitations. I find that repairs offering some flexibility generally work the best.
Much pleasure enjoyment fulfilled satisfying accomplishment from formula brought forward to great heights atop cone.......Lets turn off Babel for a sec...Uncle Doug you're my favorite, always great vids and an excellent sense of humor.Greetings from down under.
Greetings to you, George, from the Sunny Southwest, USA. Thanks so much for your very nice comments :)
Hey thanks for your reply uncle I'm so grateful you actually replied to my first ever comment.You're awesome.
You're welcome, George. Rusty and I try to respond to all comments, time permitting.
Excellent tutorial and advise..
Thank you
You're welcome, AK.
Great as per usual U.D.
Thanks, Phil :)
Hi Doug really like your videos. Whats the black silicon stuff called and where might i buy some. Thanks Ed.
I have a "doped" Altec Lancing 15" where the cone paper has separated from the doped edge ring. It is only 2-3 inches. Will the contact cement work as well? Another vid showed using a black silicone gasket material. Your thoughts please?
I have never tried to repair a doped cone, Vernon. If the separation is between the paper cone and the doped perimeter, it might require a patch to reconnect them. You can use contact cement and lightweight, thin cloth or (believe it or not) a piece of dollar bill. Apply a thin coat of cement to both surfaces, wait a few minutes for the solvent to evaporate, and then apply the patch over the split. You really have nothing to lose (except maybe a dollar) by trying to fix it, since the only alternative would be a (expensive) re-coning.
Great video!
Thanks, Mr. M :)
Thanks Uncle Doug! What are the Altec-Lansing and JBL reconing kits selling for these days?
Greetings, PB. A quick look at an Internet sales list has them running from about $75 to $125 plus shipping. In some cases, i.e. with Celestions, Eminence, etc. it would probably be cheaper to simply replace the speaker rather than the cone.
Great video. Thank you!
You're welcome, Jorge. I'm glad you liked the video :)
Hi Doug,
I have a Magnatone 280A with seamed paper cones the curve from the surround to the voice coil. Will the contact cement work to reseal this seam?
I'm a little confused by the question, Justin. If you want to patch the cone to voice coil, use epoxy. If you want to patch the area of the cone between the voice coil and suspension, use silicon glue or woodworker's glue. If you want to repair the suspension, use silicon glue or contact cement and a paper patch.
Wonderful tip. Thanks
You're welcome :)
very good, thank you for sharing, its very much appreciated, I think its a good idea
You're welcome, David. Thanks !!!
Hello and thank you for your videos, this one caught my eye. I just got a pair of Fisher Stereo, Early/Mid 70's era. The boxes are beat up, but another time. The speakers look to be in good condition, but I will probably us this before using them. I have just one issue with one of the big 12" speakers has what looks like a spot of moisture got on it and the paper is no longer smooth like the area around it. About 2" long and 1" at the widest, like a tear drop shape. Is there a way to stabilize this and save the speaker, would this method be okay to try? Thanks in advance.
Stereo speakers, especially those which come in sealed cabinets are generally not the best for guitar use, Bob, but if you plan on using them for your stereo, then I suggest that you simply test them and see how they sound. I really don't know of any way to improve water warpage in a speaker cone.
hey, Uncle Doug! I have a Behringer Fender Twin knock-off, and about 5 days ago i left it in my car (cone up) and there was a leak in the in roof. a good amount of water got all over the amp. the top, in the cones, pretty much everywhere you don't want water to get in your amp. I've set it on heater and it's been drying off for 5 days. it wasn't soaking in the car, just the trip home I'm imagining it got when and a little bit before that possibly. I looked at the speaker cones after an hour or two of drying, and I saw that the left speaker cone was wet around the edges and there was a small quarter sized soaking stain above the bottom of the speaker. should I treat both of these speaker cones before using the amp? I think it's a relatively new amp, probably made within the decade. what do you think I should do?
That's a tough one, Craig, since there is no way of knowing how much damage was done. I would give it plenty of time to dry out and then try turning it on using a current limiter (see my video) to protect against short circuit damage.
Uncle Doug well, I'm mainly worried about the speakers. I figure the amp and it's circuitry is fine, but what should I do about the speakers?
I've used "copydex" a latex based adhesive (solvent is water) on the fixing surrounds and even tissue paper and similar (not paper tissues!) with PVA to span tears in the cone - never used a contact adhesive though, no idea what the nearest UK equivalent to Weldwood would be.......... EVOstick?? (a nasty browny / beige solvent based adhesive)
I'll definitely try using a silicone for little repairs.
thanks again for all your work in making these great vids.
You're welcome, Mike. Your comment will now offer advice to future viewers. Thanks for your input :)
Greetings Uncle Doug--
Happy Holidays, and thanks for the education. I'm rapidly learning a rare skill set. This episode was especially revealing. I've got a 10", 5w Marsland with an app. 1oz. alnico magnet (ca. 1950). Came from a butchered old Regal guitar amp. The amp section was a basket case, and the speaker cone cracks when it is touched. Can contact cement be used to rejuvenate the whole cone? If so, is there any way to thin the contact cement to minimize added weight to preserve the original motor resonance, and break-up characteristics?
Cheers.
Greetings, Stephen. A cone that cracks when you touch it may be too far gone for this process, but you can thin the contact cement with lacquer thinner and gently apply a couple thinned coats. Good luck.
@@UncleDoug Thanks. I'll try that. I like the speaker.
Congrats on 100k Doug! Things sure have blown past being precious about talking about a farting speaker. That was certainly a better time.
Thanks, Rich :)
Any thoughts on coating foam rubber surround, I used rubber cement and thinly coated the foam rubber surround in hopes the foam rubber won't dry and crack in the years to come, these are 15" woofers rated at 700 Watts RMS, not manufactured anymore, any thoughts?
In my experience, there is virtually nothing you can do for foam surrounds. Solvent-based contact cement tends to dissolve the foam if you're not careful. Check the video description and contact the re-coning supplier I used. They may have foam-surround cones or know where you can get generic ones to repair yours.
Thank you for the info ,the glue you are talking about is that that aleenes,s glue
I'm not familiar with the glue you named, Ron. The brush-on contact cement is made by Titebond and has the volatile (not water-based) solvent.
Great video. I'm restoring an old Sony CFS-45 and the speakers are developing tears along the circumference of the cone, just where it meets the surround. I'm thinking of trying the contact cement, but it does get really hard after it ages. Wouldn't that affect the speaker's excursion?
Thanks, MS. It takes a long time for the contact cement to get that hard, but there is another alternative. I recently saw some cones that had been repaired by a radio collector using clear silicon caulking material. He spread a thin, uniform coat (about 1/32" thick) around the perimeter suspension area with a soft 1" wide brush and let it set up overnight. The speakers looked like modern "doped" speakers and sounded wonderful. To be honest, I think I'm going to change to this material, which is readily available at any building supply store, dirt cheap, tough as nails, and will (probably) never get hard.
Good idea. However I did some more research and found that people had good results using a fairly ubiquitous water soluble tacky glue. I used it on both speakers and it worked great. The nice thing about it is that it takes a little while to set so I had enough time to manipulate the damaged pieces into place. Afterwards, the suspension maintained a lot of its flexibility and I detected no change in speaker tonality. But this set is definitely not HiFi so I can't say how it would affect higher-end speakers. I guess the real test would be its durability.
Thanks again for pointing me in the right direction. I would not have even been exploring this had it not been for your video.
You're welcome, MS. I'm glad you were able to restore your speakers to good working order.
Have your ever used something like modge podge to add a layer of protection using a sponge brush?
I've never heard of "modge podge", Omax. The contact cement seems to work fine for me.
Hey Doug the weld wood your using is it oil based or the water based one? Reason is because I'm out here in California and may only have access to the water base formula.
I use the deadly, carcinogenic, environment-destroying form of Weldwood that is forbidden in (sissy) California, Dave, but I understand that the water-based formula works just fine.....it just doesn't cause as much mayhem :)
thanks ! found a vintage pevey 4 12 cab in a junk pile .did all your steps ! let ya know when im done !
I hope the four "patients" all make a complete recovery, Chris. Good luck.
Great help, Thanks!
You're welcome, Mr. P
this is an awesome video im doing this on a speaker tear on an jensen 5pm 15inch which are so hard to find i have three tears so i hope it works !
I hope so too, Johnny. Best of luck !!
jensen are awesome!
Hi, UD! ... Still love your videos.
Glad you still like them, David :)
Uncle Doug, do you have any advice or a video on the topic of replacing a voice coil while retaining the cone in place? I two 15 inch speakers to repair, both with cones that appear good; they are 15 inch Electro voice (EVM 15L) and JBL (E130) speakers which I think date back to the early 80’s.
No video on that specific topic, C, but it involves surgically removing the VC from the spider and cone, then reinstalling a new VC. It's simply a matter of careful surgery ;)
I take that back if it is a paper edge (One peace cone). However it could be done but would change the performance of the speaker. If the cone is not damaged the edge can be trimmed so it can have a foam edge replacement there are many examples of re-foaming a speaker cone on CZcams and the net.
Uncle Doug, as a reminder I now own one of your rebuilt speaker cabs. Well, the cone has a crack in it, as of today. Is this still a reasonable fix, or do you have another option? Thanks and Happy New Year.
It depends on where the crack is located, Louis, but this method would be a very simply and inexpensive way to fix it, if it can be repaired.
H uncleDoug again. I hope you and Rusty are doing well
I have a question for you, but it might not be your field. I need to fix the leads on a vintage speaker , the location is on the cone side of the speaker, where the wires goes through the speaker cone wall leading to the very fine wire (pigtails?) that attaches to the voice coil. there is a short on one side. In order for me to fix it. I must carefully remove the adhesive, re- attach, then cover wires with some sort of adhesive again. I cannot damage the cones in the process, they are not replaceable. So what do I use to remove the adhesive? or how do I do it?
+AmIonArock This is not an easy task, Amlon. I know of no chemical that will dissolve the glue, so I use an Xacto knife to physically remove it. After repair of the wires, I cover them with 5-minute epoxy. Good luck.
+Uncle Doug Thank you, for advice of your experiences also I will try your contact sealer idea as well
You're welcome
Weldwood, my head is still spinning from the last time I used that stuff. Adequate ventilation is beyond a must with this stuff.
Rusty and I experienced some vivid hallucinations, robbed a 7-11, and were hung over for 3 days, US, but other than that.....no problems :)
I have two old Magnavox 12" field coil speakers from 1947 and they both need to be reconed but I can not find the materials to do it. Do you know either where to get the materials or a reputable reconing company that I could send them to for a recone?
Contact the people at the Speaker Exchange to see if they can help. Good luck.
I Have this Speaker it has a tall alnico magnet and IS one of my favorite Guitar speaker i used a pair in a fender Twin till i got some Jbl d120f and a jbl d131 ..which is my fav sounding but now switching due to Weight.. to Phillips traynor speakers ..In fact i have one like yours that's been re coned and sounds like crap cause they use "krapton" plastic voice coil formers then the original Paper, higher power but less highs.. thanks for the tip :) ...i always used to use clear/black silicon
Greetings, B2. Your opinion of Kapton VC forms is shared by others. Here is an excellent discussion of the issue: wgs4.com/paper-or-plastic-great-kapton-vs-paper-voice-coil-former-question I think re-coning any vintage speaker is a real gamble. Sometimes you have no choice.....i.e. the cone and/or VC are utterly destroyed.....but if you can repair the original cone or reattach a VC wire, then IMHO you are always better off sticking with the original parts.
Thanks for the interesting link ..but the 1st use of krapton was used by Jensen in '63 as was the ceramic magnets ...Your so right as I have a JBL D131 I fixed and had one that had a new recone kit ..it was like night and day the Old Org one was Way better and the new sounded like my strings were dead, but like you said have no choice some times .. i hate when people recone when all they need is a new cone while the voice coil could of been reused...Always loved Vintage speakers and to play each one on a tube amp for the guitar Altec 417 is my next Fav ..Thanks for replying
Uncle Doug. Big fan. So what can I use to clean a silver panel Fender without removing the print ?
+LAURENCE SCHAEFER A damp rag is about all I would trust, and even then, if you rub hard, some of the screen printing will come off. These panels are very difficult to clean without causing more harm than good.
I use some Method household cleaning spray or Windex on a rag or paper towel. The paint is usually pretty robust; just don't scrub with anything abrasive.
wonder how much the contact cement treatment might raise resonance on a pleated cloth surround 12" which has moving mass in the 35 gram region - ?
I have no idea, KK, but I would think that any process which stiffens the suspension of a speaker would probably raise its resonant frequency.
Good Info
Thank you for a straight forward, knowledgeable, no nonsense video.
I swear, I've been watching toothless yokels for 2-hours, who have all obviously been huffing more of their glue than using it to fix speakers. So frustrating!
Thank you!
You're quite welcome, Tommy. I had to laugh over the image you described with the toothless huffers :):):) Best of luck with your projects.
Although this is an older thread, here goes: I have an old 2001 BMW 325i that my son drives. It has a 2 ohm sound (3 speaker-tweeter, mid, woofer system and 3 speakers per door (paper cones by HAES). I bought original replacement HAES 6 1/2 lower speakers online. they look new. I would like to "condition" the Paper cones, and the surrounds before I put them in. Can you suggest what to apply to the paper cone, and what to apply to the surrounds to keep them lasting longer? Thanks!
This more of a "HiFi" question than one relating to vintage tube guitar amp speakers, David. I am not familiar with the concept of conditioning cones. Sorry....perhaps another site or forum could help you..
i took a chance and "doped" the cloth surrounds using 100% pure silicone glue. its recommended on paper surrounds not so much on cloth. it worked fine for me
That's good to know, Miguel. Thanks.
Hi, I have an 18" speaker in a 1970s bass cab that is rattling when I boost the bass and play a low A and surrounding notes. Will this contact cement trick work to solve this problem? I can't detect any holes of kind in the cone, so I'm hoping this will work. Let me know! Thanks!
Stiffening the cone with contact cement may help a little, but when a speaker begins to rattle, it's generally due to the voice coil bottoming during the inward excursion of the cone. This tends to happen when the speaker suspension is old, weak, and worn out. You will probably end up having to either back off on the bass enhancement and volume.....or re-cone or replace the speaker.
Can the rattle you describe sound mechanical? I hear this in a Jensen speaker in a Blues Junior in the bass notes.
I have a 66 Fender Vibro Champ. Anything past 5 on the volume and it starts to buzz. It’s been sitting 30 years and the cone looks dry. I see no rips or holes. I like the sound below 5. Would doping the speaker fix the buzz? And without changing the tone much? Could it be a voice coil or is the cone just too dry and stiff? Thoughts on reconing ?
Try the methods in the video. If they help.....great.....if not, then you are no worse off. The original VC speaker is not, in my opinion, worth re-coning. Infinitely better new speakers are readily available and quite affordable. Keep the old speaker in a box, for when you sell the amp.
@@UncleDoug thanks for responding!!
Hey Uncle would this kine repair work if your cone is torn at bottom near coil?
You would need to use some white glue to attach a paper patch over the tear, Eddie. Repairing tears in the stiff parts of the cone is fairly easy. The perimeter suspension is more difficult and requires contact cement.
Hi - Can you coat the whole cone with this contact cement successfully?? I have some 30 year old speakers that have started to separate / deteriorate further down in the cone. Just wondering. Thx -
I guess you could, but the elastic nature of the contact cement is really suited to the flexible perimeter suspension, not the cone.
The extra weight will dramatically affect the tone. Better to just get it reconed.
Uncle Doug you also effectively "doped" the surround which will translate(depending on the amount used) reduced spikiness in upper mids and treble with having less effect on the extended treble frequencies.Result ='s net loss in upper mids/treble while retaining extended response in the "sparkle" and "air" part of the treble spectrum.Also the speaker is less likely to suffer cone cry now.
Applying contact cement to a heavily used, somewhat floppy old vintage speaker is a remedial action to extend the useful life of an otherwise irreplaceable device. No doubt some (high) frequencies are sacrificed by stiffening the weak suspension, but overall, it's the price you must pay to regain the entire lower to mid-frequency spectrum.....which caused the "floppiness" in the first place.
Yes,I did not mention those benefits as you already have.I only added what I did to let people know the other effects,which,by the way,can be used to deliberately shape the tone.The famed tone of a Celestion Greenback and G12 65 owe in part to the doping used,it smooths out the upper mid spikiness.IE it's not always a "price you pay" but can benefit the tone..depends on what you're after.Thanks for the video btw
You're welcome, ZZ. Thanks for your input :)
I used to work with a lot of pure silicone caulk - same chemistry as RTV. To thin the material, and especially to get it off your fingers, denatured alcohol from the hardware store will do it. It was labeled either shellac thinner or denatured alcohol, same stuff. Once the silicone has set though, the alcohol won't do anything so get to it early!
That's a good tip, EJ. I use a Scotch Brite on my hands to remove dried silicon sealer.
Man you are good...gretting s from Sweden
+Gabriel Hamburger Thanks, Gabe :)
;) people like guide the next generation..yes ...YOU WMAKE THE HISTORY pls keep it like that
We will, Gabe :)
If you have a tear on the cone (not near the edge) is using tissue paper a good way to reinforce the repair. I see video where they're using Elmer's glue and tissue paper (some used black tissue paper). Thanks and great video as always...
Philip
A tear in a non-flexing portion of the cone can be reinforced with glue and paper of your choice. Bear in mind this is only to prevent the tear from growing and should not be done on the flexing suspension portion of the cone.
I just bought some new speakers for my fender twin. and it makes a buzzing sounds when I turn it up like it's blown. if I do this will it stop ?
This process is to rejuvenate old, semi-worn-out speakers, K2. I don't think it's appropriate for new speakers. If they're both buzzing, then it may be your amp. If just one buzzes, it may be faulty. You could test this by playing through one speaker at a time.
I wasn't rolling MY eyes. Not at all. Great tip and I am going to do it.
Carl Rudd Glad you liked it, Carl. Let us know how it turns out.
Doug.... it's an 8" Rola in the SUPRO 'Special' I mentioned in that other video. :)