It´s a thicker than usual Latex emulsion/suspension.
Looks white because the tiny latex droplets refract/reflect light in the same way as in milk, but once suspending water dries they stick to each other to make a continuous and transparent film, which will never dry, and stay flexible (and sticky) forever.
You can buy the real thing at a speaker supply shop (think Parts Express or similar as "speaker dope") but if not, locally get roof sealant, the kind which is a milky liquid and is applied over tiles or bricks with a squeegee or brush.
It infiltrates the pores and cracks and seals them; being very elastic means it stands summer/winter temperature contraction/expansion.
It's the same thing, only more diluted, so you might have to apply 1 coat, let dry for a couple hours, apply another coat and so on until you reach desired thickness.
You need the product that´s applied on steps 6 and 7, any paint shop attendant will recognize it and give you a local brand.
Wash your brush under tap water after use or you will have to discard it.
Looks white because the tiny latex droplets refract/reflect light in the same way as in milk, but once suspending water dries they stick to each other to make a continuous and transparent film, which will never dry, and stay flexible (and sticky) forever.
You can buy the real thing at a speaker supply shop (think Parts Express or similar as "speaker dope") but if not, locally get roof sealant, the kind which is a milky liquid and is applied over tiles or bricks with a squeegee or brush.
It infiltrates the pores and cracks and seals them; being very elastic means it stands summer/winter temperature contraction/expansion.
It's the same thing, only more diluted, so you might have to apply 1 coat, let dry for a couple hours, apply another coat and so on until you reach desired thickness.
You need the product that´s applied on steps 6 and 7, any paint shop attendant will recognize it and give you a local brand.
Wash your brush under tap water after use or you will have to discard it.
You can use the clear version of T7000 adhesive, which is neoprene suspension contact adhesive. The other option is thicker PVA glue like Elmer's clear glue. I like clear flowable RTV used for spot sealing windshields.
Why coat it?
I once tamed a 800 hz resonance with three filters in a dsp. After linearizing it was technically and sonically ok
I once tamed a 800 hz resonance with three filters in a dsp. After linearizing it was technically and sonically ok
I have a Satori MR13P I want to treat, so I looked into this recently.
The coatings used above seem to be a water based material that goes on white then cures to clear/black.
I came across some materials like this, but was unsure if it was correct for the application.
The various DIY materials used like liquid elecrical tape, contact cement, etc. left me a bit skeptical.
I contacted many speaker repair suppliers to see if they has a water based item for damping that was compatible with the nitrile butadiene rubber (NBR) surround of the MR13P, and there was no definite answers.
Some of them use solvent based adhesive in their rubber surround kits, some water based... If they provide SDS sheets with their products that can help guide your choice.
I wanted to use a material that was as close to as what is used above, so I tried to find a water based version.
Stateside there are two speaker adhesive companies I could find: CP Moyen and Global Adhesives.
https://cpmoyen.com/
http://globaladhesives.net/surround_adhesives.htm
I inquired CP Moyen on this application, and they suggested the water based damper SP-356.
This product has not been easy to source in DIY quantities.
There was measured success using wet look made by CP Moyen available at Parts Express.
https://www.speakerdesign.net/midrange_tweaks/insignia/insignia_woofer.html
I think that if you know the composition of the surround for coating, then you can better choose a damping material that is "close".
Application is a whole other story I am trying to figure out...
I am going to rig up a turntable to spin on the damping material to the surround, use a foam brush to reduce brush marks, fit a cardboard disc to protect the cone, and possibly use delicate painters tape at the surround apex.
I will probably use some type of syringe to apply an even bead then smooth it out.
I may experiment with strips of parchment paper over the coating to smooth it while it cures... or not!
I will report back and good luck to you!
The coatings used above seem to be a water based material that goes on white then cures to clear/black.
I came across some materials like this, but was unsure if it was correct for the application.
The various DIY materials used like liquid elecrical tape, contact cement, etc. left me a bit skeptical.
I contacted many speaker repair suppliers to see if they has a water based item for damping that was compatible with the nitrile butadiene rubber (NBR) surround of the MR13P, and there was no definite answers.
Some of them use solvent based adhesive in their rubber surround kits, some water based... If they provide SDS sheets with their products that can help guide your choice.
I wanted to use a material that was as close to as what is used above, so I tried to find a water based version.
Stateside there are two speaker adhesive companies I could find: CP Moyen and Global Adhesives.
https://cpmoyen.com/
http://globaladhesives.net/surround_adhesives.htm
I inquired CP Moyen on this application, and they suggested the water based damper SP-356.
This product has not been easy to source in DIY quantities.
There was measured success using wet look made by CP Moyen available at Parts Express.
https://www.speakerdesign.net/midrange_tweaks/insignia/insignia_woofer.html
I think that if you know the composition of the surround for coating, then you can better choose a damping material that is "close".
Application is a whole other story I am trying to figure out...
I am going to rig up a turntable to spin on the damping material to the surround, use a foam brush to reduce brush marks, fit a cardboard disc to protect the cone, and possibly use delicate painters tape at the surround apex.
I will probably use some type of syringe to apply an even bead then smooth it out.
I may experiment with strips of parchment paper over the coating to smooth it while it cures... or not!
I will report back and good luck to you!
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I recently found this product called Lexel. Its very suited for coating cone to surround junctions. Its a highly damping substance that sticks to pretty much anything. It dries to a soft, pliable consistency, not excessively elastic, which is what you want. Many other latex or silicone based substances are too elastic, which by itself isn't good for damping and can actually make the problem worse.
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Thank you for the Lexel information profiguy.
I have seen some notes on its use for damping.
What types of cone / surround materials have you found it useful?
Any application tips on what worked for you?
Thanks!
I have seen some notes on its use for damping.
What types of cone / surround materials have you found it useful?
Any application tips on what worked for you?
Thanks!
You have to work fast with it in warm climates. It skins over quickly. You can slow this by diluting with hexane. Id practice on a cheap or junk driver first to dial in your application technique.
Its best for rubber surrounds to paper cone junctions which typically cause the bump around 1k on most 6 to 8" drivers and also first mode of radial breakup.
My other recommendation would be using the Alex Plus bathroom caulking, but it appears to be NLA in clear version.
Its best for rubber surrounds to paper cone junctions which typically cause the bump around 1k on most 6 to 8" drivers and also first mode of radial breakup.
My other recommendation would be using the Alex Plus bathroom caulking, but it appears to be NLA in clear version.
I was able to get some CP Moyen SP-356 so I suppose dreams do come true 😆
https://cpmoyen.com/products/water-based/
https://cpmoyen.com/products/water-based/
Thats good stuff and impossible to get ahold of in consumer quantities. How much did you have to buy at once?
I suppose I got lucky... After reaching out to all the speaker repair companies I could find with no good luck, when I inquired directly with CP Moyen for a water based damping product for use on the rubber Satori surround, they recommended the SP-356 and they then sent me a R&D sample! I think they only sell it by the gallon? I will not need a whole pint for one midrange, so I am happy to share if you cover shipping costs. It has a 6 month shelf life per product data sheet.
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Applied the surround coating today...
I applied painters tape just inside the apex of the surround, and cut a carborad disc that fit at the cone surround interface.
The tape leaves small gaps which would either be cleaned up or left in place for some asymmetry.
To get a tight fit with the disc, get the diameter "close" and use sandpaper to trim it to the best fit.
The disc was looselt attaed to the speaker dust cap with clay. (A small flap of tape stuck to the disc would have helped remove it.)
Then the driver was placed on a "lazy Susan" turntable and held in place with a small piece of clay.
A one inch foam brush was cut on each side of tip to make the tip more narrow.
The damping material was drawn into a 10 ml syringe then applied in a continuous bead at the crease between the flat and round part of the surround as the turntable was rotated.
The foam brush was used to smooth out the damping material with a few spins, with removing excess damping from the brush.
The damping was allowed to set for ~ 10 minutes, then the tape and disc removed. (This is too long, the damping material has very little slump so next time I would remove this sooner, the damping materail cured too much for a smooth cleanup.)
A damp paper towel was used to smooth the edges of the tape/disc interface with the surround. (A clean, damp foam brush may be a better tool for this, or a q-tip. However, most of the cosmetic flaws came from the attempt to smooth the too far cured damping material, thus there may be a better way.)
It did not come out super clean, but my work is more "Bro" than "Pro", looks don't matter too much at this stage.
Next, I am going to let it cure and decide of I re-coat or not after measuring T/S and/or in enclosure.
The SP-356 is very nice to work with: it stay in place when applied, cleans up with water and seems like the real deal.
I considered applying the damping material to the inside of the surround through the basket, which would have been a bit awkward, but would keep the aesthetics clean.
Hopefully the ~ 1.3 kHz resonance in my measurements get smoothed out, and a few dB of sensitivity goes down.
I applied painters tape just inside the apex of the surround, and cut a carborad disc that fit at the cone surround interface.
The tape leaves small gaps which would either be cleaned up or left in place for some asymmetry.
To get a tight fit with the disc, get the diameter "close" and use sandpaper to trim it to the best fit.
The disc was looselt attaed to the speaker dust cap with clay. (A small flap of tape stuck to the disc would have helped remove it.)
Then the driver was placed on a "lazy Susan" turntable and held in place with a small piece of clay.
A one inch foam brush was cut on each side of tip to make the tip more narrow.
The damping material was drawn into a 10 ml syringe then applied in a continuous bead at the crease between the flat and round part of the surround as the turntable was rotated.
The foam brush was used to smooth out the damping material with a few spins, with removing excess damping from the brush.
The damping was allowed to set for ~ 10 minutes, then the tape and disc removed. (This is too long, the damping material has very little slump so next time I would remove this sooner, the damping materail cured too much for a smooth cleanup.)
A damp paper towel was used to smooth the edges of the tape/disc interface with the surround. (A clean, damp foam brush may be a better tool for this, or a q-tip. However, most of the cosmetic flaws came from the attempt to smooth the too far cured damping material, thus there may be a better way.)
It did not come out super clean, but my work is more "Bro" than "Pro", looks don't matter too much at this stage.
Next, I am going to let it cure and decide of I re-coat or not after measuring T/S and/or in enclosure.
The SP-356 is very nice to work with: it stay in place when applied, cleans up with water and seems like the real deal.
I considered applying the damping material to the inside of the surround through the basket, which would have been a bit awkward, but would keep the aesthetics clean.
Hopefully the ~ 1.3 kHz resonance in my measurements get smoothed out, and a few dB of sensitivity goes down.
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The SP-355 is milky white and a litle bit more viscous. Maybe request a sample of that as well
I wish I could too, but don't think they will ship internationally
I wish I could too, but don't think they will ship internationally
You should ask them what they use. The true test will be if it sticks to the rubber sufficiently, as most water based products don't work well on non-porous surfaces. I've tried PVA on rubber surrounds and it won't stick sufficiently to be a permanent application. Many acordian surround coatings also aren't water based, so they'll also have issues.
PVA is only good on paper and fiber based cones. If it gets any moisture under it, the coating will lift. I'd be curious to try some of that SP355. Polyurethane based products may also be an option, but I'm not aware of anything viscous enough to try, being most PU products are harsh adhesives. Acrylic based substances may also work.
PVA is only good on paper and fiber based cones. If it gets any moisture under it, the coating will lift. I'd be curious to try some of that SP355. Polyurethane based products may also be an option, but I'm not aware of anything viscous enough to try, being most PU products are harsh adhesives. Acrylic based substances may also work.
@duvixan I don't usually watch YT videos, but this guy in the video knows what he's doing. I watched a few of the others he did and so far everything was done to factory standards. The Ecouton LQL150 woofer is a tough driver to replace the surround on, being it has a very tight VC gap. Not removing the DC and using shims makes this a difficult thing to do without ending up with a rubbing VC.
Dynaudio is also hard to refoam due to tight VC gaps. The large VCs on these drivers are very fussy to work with. I refoamed my fair share of Dynaudio and can attest the work done in these videos is superb.
The coating they use on the surround looks to be PVA, but I could be wrong. The ScanSpeak driver they coated was done correctly, but I'd be worried if a pair of drivers would match after this was done. Its incredibly hard to keep the coating the same weight of material for a matched pair of drivers.
I wouldn't hesitate to give this guy my business if he was in the US. Sadly many of these guys are dying off and there's no one to replace them. Pretty soon everyone will be using sound bars and little crappy powered computer speakers. I remember the 80s when people built their own speakers, which was alot of fun and very gratifying. Now we just buy plastic disposable junk.
Dynaudio is also hard to refoam due to tight VC gaps. The large VCs on these drivers are very fussy to work with. I refoamed my fair share of Dynaudio and can attest the work done in these videos is superb.
The coating they use on the surround looks to be PVA, but I could be wrong. The ScanSpeak driver they coated was done correctly, but I'd be worried if a pair of drivers would match after this was done. Its incredibly hard to keep the coating the same weight of material for a matched pair of drivers.
I wouldn't hesitate to give this guy my business if he was in the US. Sadly many of these guys are dying off and there's no one to replace them. Pretty soon everyone will be using sound bars and little crappy powered computer speakers. I remember the 80s when people built their own speakers, which was alot of fun and very gratifying. Now we just buy plastic disposable junk.
I came across a Dutch company with cone adhesives, maybe they are a lead? Here is the SDS with contact info https://speakerrepairshop.nl/other/Elastische Contactlijm_EN_2.0.pdf