I've been testing the coverage ratios for The Wet Look speaker cone treatment from parts express.
Since I didn't see anythjng on line about it, I thought it would be a good idea to share the reults of my findings.
I used a blank sheet of standard white 8.5 x 10" ink jet printing paper to determine coverage, how much coating is needed to cover the white surface.
I used a lab scale to weigh the paper and coating bottle before and after application.
The test surface was 150 cm2, which required a min of 2.5 g liquid coating to fully cover the paper so that no white surface is visible.
The 2.5g of liquid dries to 1.3g final weight. Thats about 50% loss of mass once its dry in 20% ambient humidity.
The final added mass is 7 - 9 mg per 1 cm2 surface once the coating has dried.
For full coverage treatment of variouss diameter cone drivers this works out to be -
4.0" cone = 0.320 g added mass
4.5" cone = 0.440 g added mass
5.0" cone = 0.560 g added mass
5.5" cone = 0.760 g added mass
6.0" cone = 0.960 g added mass
6.5" cone = 1.040 g added mass
7.0" cone = 1.160 g added mass
7.5" cone = 1.300 g added mass
8.0" cone = 1.560 g added mass
9.0" cone = 1.810 g added mass
10.0" cone = 2.720 g added mass
12.0" cone = 4.000 g added mass
These are all approximate amounts.
Deduct for phase plugs and wide surrounds.
Add for deep cone profiles.
Add for "thirsty" cones
Since I didn't see anythjng on line about it, I thought it would be a good idea to share the reults of my findings.
I used a blank sheet of standard white 8.5 x 10" ink jet printing paper to determine coverage, how much coating is needed to cover the white surface.
I used a lab scale to weigh the paper and coating bottle before and after application.
The test surface was 150 cm2, which required a min of 2.5 g liquid coating to fully cover the paper so that no white surface is visible.
The 2.5g of liquid dries to 1.3g final weight. Thats about 50% loss of mass once its dry in 20% ambient humidity.
The final added mass is 7 - 9 mg per 1 cm2 surface once the coating has dried.
For full coverage treatment of variouss diameter cone drivers this works out to be -
4.0" cone = 0.320 g added mass
4.5" cone = 0.440 g added mass
5.0" cone = 0.560 g added mass
5.5" cone = 0.760 g added mass
6.0" cone = 0.960 g added mass
6.5" cone = 1.040 g added mass
7.0" cone = 1.160 g added mass
7.5" cone = 1.300 g added mass
8.0" cone = 1.560 g added mass
9.0" cone = 1.810 g added mass
10.0" cone = 2.720 g added mass
12.0" cone = 4.000 g added mass
These are all approximate amounts.
Deduct for phase plugs and wide surrounds.
Add for deep cone profiles.
Add for "thirsty" cones
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@Moondog55 This Wet Look coating is more flexible when it dries and has better dampening properties than the standard PVA glue formula in Mod Podge and other puzzle coats.
I'd say its identical to Visaton LTS50 how it feels when goes on and behaves after curing. Dilution is recommended for larger cones to get more uniform, controlled coverage. Distilled water would be just fine for this purpose. I'd use no more than 20 % water for dilution.
I've used this Wet Look and LTS50 coating in very thin amounts on compression driver membranes. Its very affective for taming edge resonances on Ti membranes and others with sharp breakup peaks. The beautiful thing is it can be cleaned up and even removed with isopropyl alcohol, so its possible to experiment with various patterns and thicknesses on the same driver.
Another good use is for reducing the primary radial edge resonance on some rubber surrounds, even with Alu or other metal alloy cones as well as PP and fiber composites ie. CF or FG.
Its also very effective at controlling some resonance modes on spiders and the back of cones. Even just to increase cone mass without excessively suppressing the driver's top end reproduction.
I'd say its identical to Visaton LTS50 how it feels when goes on and behaves after curing. Dilution is recommended for larger cones to get more uniform, controlled coverage. Distilled water would be just fine for this purpose. I'd use no more than 20 % water for dilution.
I've used this Wet Look and LTS50 coating in very thin amounts on compression driver membranes. Its very affective for taming edge resonances on Ti membranes and others with sharp breakup peaks. The beautiful thing is it can be cleaned up and even removed with isopropyl alcohol, so its possible to experiment with various patterns and thicknesses on the same driver.
Another good use is for reducing the primary radial edge resonance on some rubber surrounds, even with Alu or other metal alloy cones as well as PP and fiber composites ie. CF or FG.
Its also very effective at controlling some resonance modes on spiders and the back of cones. Even just to increase cone mass without excessively suppressing the driver's top end reproduction.
Would this help a situation where the edge of the cone is operating out of phase with the center? Is something stiffer recommended? Or, just buy a different woofer? 🙄
Edit: I was thinking of using lacquer.
Edit: I was thinking of using lacquer.
@Arthur Jackson No, more than likely not. It doesn't stiffen. For that you'll need to integrate some sort of stiffer radial fibers on the cone. They sell CF, GF and Kevlar weave, as well as straight cut long fibers, which can be applied with epoxy. I've also tried very thin CF rods. They work very well on larger cones. You just initially apply them with a drop of cyano, tacking nto place, then coat with a thin layer of epoxy resin.
Ecouton has used a similar cone stiffening method since the 1980s.
Ecouton has used a similar cone stiffening method since the 1980s.
Looks interesting but I can't find any in Oz and I'm not paying $55- for postage on a small bottle. I guess I keep using wood glue diluted with water.
Titebond Ultimate does go on a bit differently to ordinary PVA and seems to dry harder, maybe I'll try that next time because it seems that I use whatever wood work glue I happen to have
Titebond Ultimate does go on a bit differently to ordinary PVA and seems to dry harder, maybe I'll try that next time because it seems that I use whatever wood work glue I happen to have
MSDS shows ammonia
Typically used to adjust PH or shelf life of Latex or acrylic.
It helps Latex bond better so that is my guess.
Common dilution 2 parts latex 1 part Ammonia
Typically used to adjust PH or shelf life of Latex or acrylic.
It helps Latex bond better so that is my guess.
Common dilution 2 parts latex 1 part Ammonia
@Moondog55 They carry 2 different sizes of the product. I can't see how it costs $55 to ship a few ounces. There has to be a reasonable way to ship this, as its not a hazardous substance. Visaton LTS50 is almost the same stuff (based on my testing) and doesn't cost that much over in Europe. I've used it back in the 80s.
@WhiteDragon The ammonia is needed to bond with rubber and other polymers, as well as stabilize the emulsion, stays in solution longer in a wider temp range. The ammonia in this product is a small amount, similar to that of a latex based paint. They used to make this stuff in clear, but it apparently didn't sell that well.
It would be a great test to use this product in a slotted cone arrangement, specifically with larger diameter cones and on rubber surrounds. I'm willing to try this stuff on my SB34NRXLs depending on preliminary measurements. If this reduces the 800 hz wiggle, we'd have a winner.
@WhiteDragon The ammonia is needed to bond with rubber and other polymers, as well as stabilize the emulsion, stays in solution longer in a wider temp range. The ammonia in this product is a small amount, similar to that of a latex based paint. They used to make this stuff in clear, but it apparently didn't sell that well.
It would be a great test to use this product in a slotted cone arrangement, specifically with larger diameter cones and on rubber surrounds. I'm willing to try this stuff on my SB34NRXLs depending on preliminary measurements. If this reduces the 800 hz wiggle, we'd have a winner.
Have a look at the USPS website and then do a calculation in Aussie dollars.
Costs here in Oz are crazy due partly to the high cost of shipping and/or postage
Costs here in Oz are crazy due partly to the high cost of shipping and/or postage
My mistake as postage on the big bottle is even higher Screen dump attached
and remember to divide by 0.635
I thought about doing that years ago, but since I am old, I was thinking of Elmer's glue and spruce strakes. I figured it would be much too heavy. Carbon fiber and epoxy will be far lighter and stronger.
I've also thought about doing like Scan Speak and put cool wave patterns on the cones with cyanoacrylate. I've used super glue coated cardboard for model rockets and it's very light and stiff.
@Arthur Jackson The big issue with superglue(cyano) is its too stiff and doesn't dampen whatsoever. The other problem is questionable compatibility with other materials. They sell a rubberized cyano glue which is ideal.for surrounds and spider to basket bonds. If you want to use an organic substance on a paper cone glued with rubberized cyano, balsa wood would be best.
There's alot to consider when modifying a cone on an existing driver. Usually you'll go backwards with it. Using some light weight dampening agent is likely going to result in the best possible outcome. If the.driver has a rubber surround, a bead of dampening material on top of the surround flange on the cone edge will give you the best chance of improving linearity and FR, specifically the upper end of the FR and the decoupling the surround (which usually causes a dip between 500 hz - 1k).
If you absolutely want to add some sort of beneficial material to the cone, stick with thin CF rod and aooly with regular cyano glue. A radial pattern fanning out from the dust cap is the best plan of attack IMO. It will reduce driver sensitivity, depending on amount of mass added. A few strands of CF rod spaced unevenly will likely have the best outcome. I'd avoid the temptation of totally filling up all the available space.
You will for sure go backwards with some drivers, so experiment with cheap drivers first before ruining more expensive ones. Adding more than 10 - 15 percent cone weight isn't going to have a positive outcome. You're just reducing sensitivity, increasing Qts and hurting upper FR extension.
There's alot to consider when modifying a cone on an existing driver. Usually you'll go backwards with it. Using some light weight dampening agent is likely going to result in the best possible outcome. If the.driver has a rubber surround, a bead of dampening material on top of the surround flange on the cone edge will give you the best chance of improving linearity and FR, specifically the upper end of the FR and the decoupling the surround (which usually causes a dip between 500 hz - 1k).
If you absolutely want to add some sort of beneficial material to the cone, stick with thin CF rod and aooly with regular cyano glue. A radial pattern fanning out from the dust cap is the best plan of attack IMO. It will reduce driver sensitivity, depending on amount of mass added. A few strands of CF rod spaced unevenly will likely have the best outcome. I'd avoid the temptation of totally filling up all the available space.
You will for sure go backwards with some drivers, so experiment with cheap drivers first before ruining more expensive ones. Adding more than 10 - 15 percent cone weight isn't going to have a positive outcome. You're just reducing sensitivity, increasing Qts and hurting upper FR extension.
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That's what I'm scared of. I think my best bet to use the drivers is to cross over below the response dip, like at 500hz or so. They aren't the best drivers but I would like to get out of them all that I can. Maybe a little damping is all I can hope for. After the prototype is acceptable I'll move on to better drivers. I'll try the Wet Look on some midranges with peaky response.
Just a 10" Dayton Pro. I bought the 12" and it seems to be a bargain, so I thought I'd try the 10 and it's not nearly as good. I'm relegating it to the experimental drivers collection. The 10 has a dip right where you said it would be with a cloth surround though. Applying Wet Look, strakes, or cyano lines look like a good experiments to me. All recommendations will be helpful in my quest to polish this turd.
I'm assuming the dip is caused by the edge of the cone working in opposite phase to the center of the cone but could it be something else?
I used this woofer in a WAW experiment and it worked fine because I crossed it over at 300Hz.
I'm assuming the dip is caused by the edge of the cone working in opposite phase to the center of the cone but could it be something else?
I used this woofer in a WAW experiment and it worked fine because I crossed it over at 300Hz.
The surround is likely the culprit for that dip. Don't be tempted to apply dampening to one of the surround reliefs itself. That may worsen the issue. With surround reflections like this its best to apply dampening to the outer most edge of the cone. I'd limit it to 3 applications. If it doesn't make enough of a difference at that amount, any more just will lower sensitivity and affect top end rolloff.
What I'd do there to simplify the application of dampening agent is to shore up the inside edge of the cone outer diameter with a thin bead of blue tack and apply dampening with a small applicator bottle with needle, then remove blue tack after about 30 min.
You can also use electoral tape but be careful when removing it to avoid pulling off cone material or leaving behind adhesive. A round plastic container lid is also useful. Easy way to get a clean edge is to ine the outer edge of the lid with Teflon tape, then hold the lid in place with a weight.
What I'd do there to simplify the application of dampening agent is to shore up the inside edge of the cone outer diameter with a thin bead of blue tack and apply dampening with a small applicator bottle with needle, then remove blue tack after about 30 min.
You can also use electoral tape but be careful when removing it to avoid pulling off cone material or leaving behind adhesive. A round plastic container lid is also useful. Easy way to get a clean edge is to ine the outer edge of the lid with Teflon tape, then hold the lid in place with a weight.
This driver is a good candidate for treatment. It shows moderate breakup being used to extend FR and can use some surround treatment. The cone is very.light and shouldn't be used for aggressive horn loading, but as a midrange direct radiator it shows great potential.
