Speakers "fatigue" ? Need help !

[hugh811]

Good morning,

I am looking for a special substance to "refresh" the paper surround of vintage speakers in order to improve the performance of these. I read a number of threads on "fatigue speakers", but it seems that there are different views and I can't find in there the answer for me. Let me make it clearer.

Few years ago when I was in Asia, a local audiophile gave me a small glass tube containing a substance which is transparent, sticky like paper glue and non-dried. I have applied this on the textile fabric surrounds of vintage speakers like Whaferdale W70, Bozak, coaxial drivers and also on paper surrounds of other drivers of my collection. But not on the foam or rubber surrounds. Pricing is 20 USD for this small glass tube, and it is enough for one pair of 12" woofers, two light coats in front and two others coat from behind the surround. Just applied on the surround, absolutely not on the cone

Why it is needed? I realized that the surround of vintage gears became more stiff after so many years, the original black coat on the surround became dried and less sticky, and the bass coming from the fatigue drivers became very dry. And I realized also that on many vintage speaker surround, there is always a coat of black, lightly sticky and non dried substance (Tannoy, Altec).

The result is far from satisfying. I am very happy with. The improvement is like day and night. And there is still a non dried coat there on treated speakers after years. It is still sticky.

The senior audiophile never unveils what it is the substance.

My question is do you know what it can be and where in USA I can procure this kind of anti-fatigue substance for vintage speakers, the paper surround to be more concrete? (I saw that there is a possibility to "repaint" the cone with a black substance, for sale on some website. Your speakers will become totally black. But it is absolutely not my favorite approach).

Or may I reformulate the question: what is the coat that companies like Altec, Tannoy have applied on their paper surround ?

Many thanks for your help.
Hugh811

 

[Poinzy]

From what I've seen, the best substance would be diluted driveway sealer, or something like it. I'll admit, I don't know anybody who has retreated his speaker drivers.

 

[NH-MAN]

 

[hugh811]

Thanks to Poinzy for your post.

There are many vintage paper cone speakers that are in good condition except the wet coat on the surround. How to solve the problem? Replace the whole paper cone and surround is not my choice. I will definitely not in this case.

So I think the best question to have the right answer is: "What is the coat that companies like Altec, Tannoy have applied on the paper surround of their famous vintage drivers"? Any help out there would be very appreciated !

 

[bberkom]

My Sony SS-3300's have 12" woofers with flexible accordion coated paper surrounds like the ones you describe, and I haven't felt the need to retreat them. They are from around 1970, and I did notice the bass improve after using them regularly for a few weeks. They needed to be broken in again, but the surrounds are still flexible. Just my experience, but maybe try using them for a few weeks and give them some power and see how they respond.

 

[hugh811]

Thanks to bberkom for your post. I know It works but I can assure you that your drivers will not give the full performance as they used to do decades ago.

As I mentioned, the question now is "What is the coat that companies like Altec, Tannoy have applied on the paper surround of their famous vintage drivers"?

Maybe please find here attached an image to see what I want to mean. Right below is a driver of Tannoy gold LSU 12". As you can see, there is a black and wet coat on the paper surround. And it is lightly sticky when touched.

 

[Gazdatronik]

Good morning,

I am looking for a special substance to "refresh" the paper surround of vintage speakers in order to improve the performance of these. I read a number of threads on "fatigue speakers", but it seems that there are different views and I can't find in there the answer for me. Let me make it clearer.

Few years ago when I was in Asia, a local audiophile gave me a small glass tube containing a substance which is transparent, sticky like paper glue and non-dried. I have applied this on the textile fabric surrounds of vintage speakers like Whaferdale W70, Bozak, coaxial drivers and also on paper surrounds of other drivers of my collection. But not on the foam or rubber surrounds. Pricing is 20 USD for this small glass tube, and it is enough for one pair of 12" woofers, two light coats in front and two others coat from behind the surround. Just applied on the surround, absolutely not on the cone

Why it is needed? I realized that the surround of vintage gears became more stiff after so many years, the original black coat on the surround became dried and less sticky, and the bass coming from the fatigue drivers became very dry. And I realized also that on many vintage speaker surround, there is always a coat of black, lightly sticky and non dried substance (Tannoy, Altec).

The result is far from satisfying. I am very happy with. The improvement is like day and night. And there is still a non dried coat there on treated speakers after years. It is still sticky.

The senior audiophile never unveils what it is the substance.

My question is do you know what it can be and where in USA I can procure this kind of anti-fatigue substance for vintage speakers, the paper surround to be more concrete? (I saw that there is a possibility to "repaint" the cone with a black substance, for sale on some website. Your speakers will become totally black. But it is absolutely not my favorite approach).

Or may I reformulate the question: what is the coat that companies like Altec, Tannoy have applied on their paper surround ?

Many thanks for your help.
Hugh811

I've heard some say its not too much more complex than rubber and naptha mixed together.

 

[Gazdatronik]

Thanks to bberkom for your post. I know It works but I can assure you that your drivers will not give the full performance as they used to do decades ago.

As I mentioned, the question now is "What is the coat that companies like Altec, Tannoy have applied on the paper surround of their famous vintage drivers"?

Maybe please find here attached an image to see what I want to mean. Right below is a driver of Tannoy gold LSU 12". As you can see, there is a black and wet coat on the paper surround. And it is lightly sticky when touched.

View attachment 1051082

No speaker of age performs the same as new, the parameters gradually change as they age, only some of the changes having anything to do with the surround.

 

[teebee]

Speaker doping. Maybe PE's "The Wet Look"?

 

[jberger]

Are you looking for another tube of the clear sealant that you described using on cloth surrounds, or are you looking for something different (same substance/different color, or different substance entirely)?

If it's the clear sealant for cloth surrounds, I've had good results with a sealant from the seller "vintage-ar" on ebay.

 

[Zonker92]

http://audiokarma.org/forums/index....-cement-for-klh-cloth-surround-doping.615202/

https://www.ebay.com/itm/ACOUSTIC-R...UND-WOOFER-SEALANT-KIT-ALSO-KLH-/192338658040

 

[doctorolds]

The sealant sold by vintage-are on eBay is correct for AR and KLH speakers for sure, but for cloth surround's.

I believe the OP I referring to the accordion type paper surround's if I am not mistaken. If I had to recommend something it would be that sealant.

Does anyone have an idea of what type of sealant was used on an HPM-100 woofer? I don't know, but I think it was similar to the clear sealant that vintage-are sells. Maybe someone will be able to provide an appropriate response for the OP.

 

[Retrovert]

I've heard some say its not too much more complex than rubber and naptha mixed together.

Butylene rubber and toluene.

RoyC re-created the mix, which is documented in the famous KLH bulletin.

 

[Retrovert]

The sealant sold by vintage-are on eBay is correct for AR and KLH speakers for sure, but for cloth surround's.

It is butylene rubber plus toluene. This was the same sealant used on paper surrounds.

I believe the OP I referring to the accordion type paper surround's if I am not mistaken. If I had to recommend something it would be that sealant. I do know of people that have used a light coat of Aleene's Tacky Glue diluted with water to seal them after being replaced, but I am not recommending that.

That is poor advice and it is based upon internet "facts" which have been debunked.

Using PVA (aka white glue) would be disastrous, as has been well documented here and on Classic Speaker Pages. RoyC and others tested different sealants on AR-3 drivers, i.e. they actually did experiments, and aside from butylene rubber all of them ruined the surrounds and the speakers. Every. Single. One.

The PVA cult refuses to understand that hardening or stiffening a surround raises Fs, which ruins the speaker. It may also create or exacerbate a resonance problem. Gasket cement or diluted silicone are just as bad. This has been well documented with actual experiments, yet the dogma and internet lore simply will not die. People want to believe they can "fix" something when they don't understand the chemistry or materials involved.

I urge everyone to do research on this before applying anything to a surround. Once the surround (or cone) is modified it cannot be restored, it must be replaced.

 

[Retrovert]

Speaker doping. Maybe PE's "The Wet Look"?

When a cone is altered, (a) its mass increases and (b) its resonance properties change. This alters the sound. Speaker designers expend a lot of effort making cones lightweight for better and more linear frequency response. I don't know why aesthetics (does a shiny cone really look "better"?) encourages people to degrade the sound.

 

[doctorolds]

It is butylene rubber plus toluene. This was the same sealant used on paper surrounds.

That is poor advice and it is based upon internet "facts" which have been debunked.

Using PVA (aka white glue) would be disastrous, as has been well documented here and on Classic Speaker Pages. RoyC and others tested different sealants on AR-3 drivers....

I agree with your post 100%. I was just noting that the OP was referring to the paper surround's. I would only recommend the sealant developed and tested by RoyC and only mentioned the glue and stated that I do not suggest using it. I appreciate that you verified it is the same and correct sealant for use on paper surround's, which was my guess. Thanks for making things clear and providing the additional information.

 

[woodj]

That is poor advice and it is based upon internet "facts" which have been debunked.

Exactly.

When a cone is altered, (a) its mass increases and (b) its resonance properties change. This alters the sound. Speaker designers expend a lot of effort making cones lightweight for better and more linear frequency response. I don't know why aesthetics (does a shiny cone really look "better"?) encourages people to degrade the sound.

Yep.

 

[Retrovert]

I agree with your post 100%. I was just noting that the OP was referring to the paper surround's. I would only recommend the sealant developed and tested by RoyC and only mentioned the glue and stated that I do not suggest using it. I appreciate that you verified it is the same and correct sealant for use on paper surround's, which was my guess. Thanks for making things clear and providing the additional information.

Yes, I did see you wrote, "but I am not recommending that", but I meant the advice you were repeating and not recommending was uniformly bad, based upon endlessly recirculating nonsense, and should be condemned as hopelessly flawed and a way to ruin a speaker.

RoyC's work was definitive and exactly the sort of science that audio needs.

If only people would respect the experimentalists who did the heavy lifting and repeat their work as dogma we'd be better off.

 

[NH-MAN]

As is the OP I too wonder where we can get this black sticky rubber stuff. My Allison speakers have it on the woofer and originally on the old foam surround.
I was surprised how tough it was when re-foaming my Allison's

 

[doctorolds]

Yes, I did see you wrote, "but I am not recommending that", but I meant the advice you were repeating and not recommending was uniformly bad, based upon endlessly recirculating nonsense, and should be condemned as hopelessly flawed and a way to ruin a speaker.

RoyC's work was definitive and exactly the sort of science that audio needs.

If only people would respect the experimentalists who did the heavy lifting and repeat their work as dogma we'd be better off.

Edited origanal post to avoid any confusion.