it's PVA, but its not as flexible as the standard PVA coating sold specifically for speaker cones. It ends up drying a bit closer to the stiffness of white wood glue, which is supposedly also based on PVA.
I get decent results with mod podge, but only if its thinned out a bit and applied in thinner multiple coats. Some paper cones tend to deform if exposed to excess amounts of water based coatings and can be ruined by heavier coates. I learned my lesson the hard way on some older Philips drivers.
How much depends on how long the jar has been sitting on the shelf. I ease it up 1 or 2 drops out of a syringe at a time until it is the right consistency. 5-10% by volume.
If you are going to add colour do it after you have the consistency, I typically use a high end gel food colouring, if what you have is liquid it will act as a thinner. And don’t be surprised if the colour you end up with compared to your expectations — first time i tried to make an FE126En cone blue it slowly turned green.
The coat goes on very thin, and on a come of the size i pictured, has to be done quickly as the stuff is already getting tacky before you get all the way round.
On anything that needs to go high up in frequency you do not want to use much.
With something like a woofer you have more latitude, and with some recycled woofers have done front & back, multile coats, with extra coats on th einner cone. Lowers Fs, sensitivity, rolls off the top end, often more smoothly and the coats on the inner cone an attempt to push up the dispersion as far as they went.
I have been experimenting since the late 70s. Thousands of cones.
dave
If you are going to add colour do it after you have the consistency, I typically use a high end gel food colouring, if what you have is liquid it will act as a thinner. And don’t be surprised if the colour you end up with compared to your expectations — first time i tried to make an FE126En cone blue it slowly turned green.
The coat goes on very thin, and on a come of the size i pictured, has to be done quickly as the stuff is already getting tacky before you get all the way round.
On anything that needs to go high up in frequency you do not want to use much.
With something like a woofer you have more latitude, and with some recycled woofers have done front & back, multile coats, with extra coats on th einner cone. Lowers Fs, sensitivity, rolls off the top end, often more smoothly and the coats on the inner cone an attempt to push up the dispersion as far as they went.
I have been experimenting since the late 70s. Thousands of cones.
dave
Thanks for your input.
I've used mostly the dedicated pva sold by visaton. I mainly used the coating to increase mass and Qts along with coating the inner surround edge to reduce the cone edge reflection on larger rubber surround woofers.
I read that Troels did some kind of coating on a satori (?) driver and it pretty much killed the reflection according to his measurements. Of course he won't disclose the info. Its interesting how well dampening the cone with a polymer can make such a big difference.
I've used mostly the dedicated pva sold by visaton. I mainly used the coating to increase mass and Qts along with coating the inner surround edge to reduce the cone edge reflection on larger rubber surround woofers.
I read that Troels did some kind of coating on a satori (?) driver and it pretty much killed the reflection according to his measurements. Of course he won't disclose the info. Its interesting how well dampening the cone with a polymer can make such a big difference.
Love this forum! Other guys spend their days just as I do! And share great tips. Today I stuck felt pads on my Yamaha HS7 cones and domes, and put more stuffing (denim fluff) inside. What a difference! A vintage Kathleen Ferrier track used to hoot and holler. Now she sounds smooth and musical, almost in the room.
Given that often the changes that come from treating a cone are the ability to better reproduce the really small stuff. And we well know that we have yet to figure a way to measure this so measurements may show us gross changes but the important stuff does not show.
To quote Floyd Toole:
dave