Reinforcing paper cones

[we_doyle]

(I hope I did not ask this before.) I was wanting to see if anyone had any experience or ideas about applying something like a shellac or rubbery material to the edges of older paper cones (like you find in Klipsch speakers for example) to delay or prevent their deterioration and/or separation from the frame. Now I know you can buy kits to replace or repair your surrounds. I want to prevent or delay that step.

It seems to me that there would be something one could apply like paint to the edges of a paper woofer cone and dramatically strengthen it. It would be nice to find something that would soak into the paper a little and leave a rubber like surface when dry. Naturally, you would not want to overdo it. You want something that dries flexible but that won't easily peel or flake off. I am thinking that you would just take a paint brush and dip it in this stuff and paint the parts of the paper that could use some protection.

I have noticed that the edges seem to have a rubbery substance on the surrounds when they are new. Would that be a shellac or paint like substance applied to the paper cone edges? I don't know. I am asking.

Anyway, I would like to gently apply something like this to my Heresy woofers at some places that would be most likely to tear or break away over time. They are fine right now, but I want to protect them. Also, I know about the old adage, "If it ain't broke, don't fix it." However, the fix, although doable, would be best avoided if possible, in my opinion.

So, anybody out there have any ideas, or preferably, experience?

[Daddy Dee]

you ask an interesting question.

I've been thinking that the eminence drivers klipsch uses last for decades just as they come from the factory. Don't know if their life can be extended, but their lifetime is pretty impressive as is.

[colterphoto1]

Klipsch's 'paper' cones are already a highly treated compound material. No further treatment is necessary.

A key to this is the mass of the cone and springiness of the suspension, you don't want to change the mass of the cone or the suspension characteristics of the surround AT ALL!

That being said, I have treated very aged, weather-worn cones with a quickk shot of SEM spray vinyl top coating. It's very light and flexible.

Michael

[we_doyle]

I did buy some glue at Michael's (the craft store chain) that is supposed to work like I want. They said it would. I have some car speakers that I took out of my Honda when I changed out the factory speakers. I thought I would use those as the guinea pigs to see how various treatments work. I have four of them removed from the car so I can try out at least four substances. I think this should be like sealing your driveway. Of course the old master, Mr. Klipsch himself, did know what he was doing and you hate to mess with genius.

[we_doyle]

Would you happen to know what Klipsch uses to treat the cones?

It seems that if we could get a can or bottle of that stuff, we could touch up the cones.

I am talking about an extremely light coat. I can understand how you could really mess up your woofer if you just poured that stuff on.

[Daddy Dee]

Eminence is the OEM builder Klipsch uses for the Heritage line woofers. I think Klipsch manufacturing uses them out of the box in the speakers (with thorough testing for quality, of course).

You might be able to identify the materials/treatments used through Eminence.

[ace168516]

Parts Express sells something called "wet look" it is a polymer based coating designed to protect paper cones. I do not think it is really any sort of reinforcement, but more to protect the appearance of the cone. It is available in clear and black...link below. I have never used the stuff, but did remember seeing it somewhere. ACE

LINKY

[George Roland]

I wonder why you are seeking a solution for a problem that doesn't seem to exist? If there are no tears or separations in your speakers and they are playing well, I would be very reluctant to mess with them. Just my $0.02.

Best,

George Roland

[Marvel]

It seems to me that there would be something one could apply like paint to the edges of a paper woofer cone and dramatically strengthen it. It would be nice to find something that would soak into the paper a little and leave a rubber like surface when dry.

Dramatically strengthening the surrounds will change the compliance or stiffness, changing the tuning.

If you have a small tear in the cone or surround, you can use some tissue paper (cigarette papers work as well), with a thinned mixture of Weldbond. That, won't change the compliance much at all, but you don't want to overdo it.

I did both foam surrounds on a pair of JBL woofers, which were full of splits. Did it change them? Probably/maybe, but now they can be used and the owner is more than pleased with the fact that it cost about $5, and an afternoon of my time while I was doing something else. I had them out on the table, and would put some on, while drying I would do other work. Let them sit over night to make sure it was good and dry.

Came out great.

[Islander]

Klipsch speaker cones tend to last for many decades without any attention. My La Scala woofers are 35 years old and sound great. Those pleated paper edges are not at all like the foam surrounds that eventually crack and fall apart. The "dope" that the edges are treated with at the factory should preserve them just fine. The speakers should not need any special attention, other than feeding them a clean sound signal at less than deafening levels.

Keep in mind that with the very high sensitivity of Klipsch speakers, the cones move very little, even when producing loud sounds. I don't think you'd ever see them moving in and out like you see in that Blaupunkt commercial. Accordingly, there is very little fatigue occurring in the cone material.

If the speakers finally fail twenty years from now, you could get the new parts to fix them, or upgrade to another model, like La Scalas or Khorns. Meanwhile, just listen and enjoy. Anything you apply to the cones is likely to mess up the sound, and not extend their lives at all, so I really wouldn't bother.

[colterphoto1]

DON"T DO IT

The kids at Michael's surely are knowlegable about loudspeaker physics- NOT

[HarryO]

I understand your thinking on this. I've seen a lot of "vintage" drivers that the cones and edges have become brittle.

There are some older speakers that would benefit from treatment of the cloth fibre surrounds. There's also "dope" to cheat on foam surrounds to extend their life expectancy.

I've also seen cloth surrounds that have been treated that destroyed the surrounds and the drivers had to be reconed because of it. (recently AR3 drivers with the cloth fiber surrounds as an example)

Klipsch drivers with the pleated surrounds are NOT one of the types that need treatment.

"Ain't broke, don't fix it"

These are generalizations that hold pretty true but there may be instances treatments could apply.

Harry

[Baker]

This is important to me asi restore 1930ss cabinet SW Fm AM just for the beauty of the cabinet.  The speakers have 100vdc voice coils and the paper cones while intact are almost 100 tears old this is why I need a source to strengthen the material.  I have gone so far as to replace cones but this is time consuming. Any ideas

[boom3]

I would address this to the Antique radio forums

https://www.antiqueradios.com/forums/index.php

 

I'm sure you are aware that the "electrodynamic" speakers of that time use the electromagnet of the speaker as a filter "choke" for the power supply. There are guys on that forum who have a lot of experience with these type of speakers.

[OO1]

On 11/27/2023 at 3:23 PM, Baker said:

 I have gone so far as to replace cones  

replace cones or dont touch it 

[teddeman]

Would this go for a pair of gen 1 Heresy?  The woofer requires no servicing?  I just got a pair of Heresy IV and am going to sell the 45 year old ones which still sound great (and look even better because I sanded the cabinets to remove the hideous brown and coated them with polycrylic).  

[Travis In Austin]

On 12/23/2024 at 1:45 PM, teddeman said:

Would this go for a pair of gen 1 Heresy?  The woofer requires no servicing?  I just got a pair of Heresy IV and am going to sell the 45 year old ones which still sound great (and look even better because I sanded the cabinets to remove the hideous brown and coated them with polycrylic).  

They shouldn’t need anything .

[JohnA]

On 12/23/2024 at 2:45 PM, teddeman said:

Would this go for a pair of gen 1 Heresy?  The woofer requires no servicing?  I just got a pair of Heresy IV and am going to sell the 45 year old ones which still sound great (and look even better because I sanded the cabinets to remove the hideous brown and coated them with polycrylic).  

 

 

If your woofer lasted 45 years, why would you think it needed treating with anything?