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Paper Cone Treatment Question

archie2

archie2

Addicted Member
I remember reading an article about a restoritive treatment for paper cones. I think it was a spray but I'm not sure. I also don't remember whether it actually preserved the cone or was just cosmetic. Has anyone heard of such a product?
I am very cautious of anything I would apply to vintage cones but if it works I'd like to explore it. Thanks.
 
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I would think if a cone is gone enough to put something on it it needs reconed. Also the additional weight and surface might make it sound different.

Just some random thoughts.
 
"I would think if a cone is gone enough to put something on it it needs reconed. Also the additional weight and surface might make it sound different."

Cone's good, just old. I was wondering if there was a preservitive on the market that would make it young again. You are right though, anything added to the cone would more than likely change the characteristics. Wish I had bookmarked that article. I know Parts Express sells something that supposidily extends the life of foam surrounds.
 
It can change the characteristics, but probably no significantly enough to worry about. Many times, the changes are for the better.
 
Reconing is certainly going to change things unless the exact original replacement parts are still available. Reconing is still an option if the treatment doesn't work, or makes things worse.
 
You could try pure latex. Yes it will change the sound of the woofer, but with the ones I did in the past it was always a good thing.
 
Coating for Paper Cone Driver

I recently posted a thread which pertains to your question-
http://audiokarma.org/forums/showthread.php?t=58799
It's a bit long, but the bottom line is that I applied a coating which definitely helped my problem- namely, "fuzzy", hollow sound from an old paper cone midrange.
I wouldn't have done it if I'd been happy with the original sound though. I don't like to mess with anything which isn't broken!
Also, I can't claim that the coating I used is the "best". I tried it because I'd used it successfully in other applications, and it seemed to have the right properties.
In my case, I'm glad I tried it.
 
Interesting post Chekov. I've done a lot of wood refinishing but I must admit I'm not familia with water soluable polyurathane. Sounds similiar in properties to "The Wet Look" application from Parts Express.
 
archie2 said:
Chekov, did you apply that solution to the surrounds as well?
Click to expand...

No.
For the woofer surround, I used a black, extremely flexible sealant which was recommended by a post somewhere on this board-
"PERMATEX ULTRA BLACK Gasket Maker", available at auto parts stores.
I bought it to seal the cloth woofer surrounds on my son's vintage KLH-17s. He's a pretty critical listener- he described the bass as being "tighter" after the sealant was applied. I'm not sure I could hear a difference- if so, it was subtle.
One thing was obvious though- before, the woofer made huge excursions. It was fun to watch the woofer dancing in tune to the beat, but it indicated that the acoustic suspension wasn't keeping the woofer under control. After applying the sealant to the surround, the motion was reduced. Also, when I gently pushed the woofer in and then removed the pressure, it bounced back more slowly- as expected.
For the Fisher XP7's , though, I really didn't notice much difference from the surround treatment alone.
 
archie2 said:
Interesting post Chekov. I've done a lot of wood refinishing but I must admit I'm not familia with water soluable polyurathane. Sounds similiar in properties to "The Wet Look" application from Parts Express.
Click to expand...

I bought it at ACE Hardware. I normally don't use it for furnature. Being water-based, it's easier (and healthier) to work with than most finishes, but for furnature, I still like the non-waterbased finishes better. It's not bad though- I used it on the inside surface of an exterior door. After 10 years it still looks as good as day1.

I use it mainly for various art projects. It works very well with paper.
 
If it went from moving a lot to restricting the movement of the cone, that would certainly explain the tighter bass. If it can't move as far, it can't produce as deep of bass and hence the apparently tighter response. Something that changed the excursion that significantly would have altered your specs a significant amount. Normally, the surrounds don't provide much, if any restoring force (the motor provides drastically more damping than any mechanical damping provided by the suspension). Honestly, I'd worry about that and that it takes longer to come to resting position when pushed in, that is not a positive thing IMO.
 
dnewma04 said:
If it went from moving a lot to restricting the movement of the cone, that would certainly explain the tighter bass. If it can't move as far, it can't produce as deep of bass and hence the apparently tighter response. Something that changed the excursion that significantly would have altered your specs a significant amount. Normally, the surrounds don't provide much, if any restoring force (the motor provides drastically more damping than any mechanical damping provided by the suspension). Honestly, I'd worry about that and that it takes longer to come to resting position when pushed in, that is not a positive thing IMO.
Click to expand...

The difference in the spring back is subtle-
Detectable when comparing the out-of-box springback with springback when in the sealed enclosure.
Not dramatic.

Also- I neglected to mention that the surround sealant is only applicable to acoustic suspension speakers with porous surrounds which were originally sealed (not foam).
 
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