GUILHERME said:
I've never painted any of the stuff on a speaker, but I use it to make oil painting medium.
My recommendation is, spend a little more and buy a jar of ready-made dammar varnish. I would not recommend buying the dry lumps of resin and disolving them yourself. The result requires filtering, and you can get an ughly goo settling out in the bottom of the container. It's sticky as heck, and it doesn't smell too good either.
7V said:
Hi Steve, Actually the Dynaudio Esotar tweeters have a fabric dome (perhaps silk?) They're no longer available to the public in the US and since they retail for over $1000.00 per pair in europe... I thought that I had better be careful and use C37, not Damar. I believe that dynaudio claims that these domes are already coated. with what? I don't know. Anyway, I've been reading the posts on these products and I'm beginning to chuckle at the responses because it reminds me of a story .
There were these 2 scientist/mathematicians standing around a flagpole trying to figure out how tall it was. They were going back and forth about the best way to calculate the height.... like using geometric formulas based on the length of the shadow and how much it moved over a given period of time as the sun
traveled across the sky , etc. This went on for hours when finally an engineer who was nearby and tired of hearing this nonsense, suddenly got up, walked over to the flagpole, pulled it out of the graound, laid it down, took out his tape measure and pulled ith the lengh of the pole and then looking at the other men said " It's 20 foot 3 & 3/4 inches" he then picked the pole back up, place it back in the ground and walked away. with this one of the men looked at the other and said: "Engineers.... You ask them for the height and they give you the length".
Anyway, being a scientist myself, I find it annoying when people stand around an theorizing about something when the answer is easy. I've decided to buy a cheap fabric or paper dome tweeter. Remove the dome and weigh it on a very sensitive scale prior to and after application to see how much mass the C37 really adds. From there calculating the percent increase in mass should be easy. 🙄
Yes but it does more than just add mass (or at least its supposed to).
I think I will try the diluted white glue on some cheap subwoofers I have.
btw good story 🙂
I think I will try the diluted white glue on some cheap subwoofers I have.
btw good story 🙂
I'll use that story, I'm sure.kensetsu said:
As thomas997 said, it's not (solely?) a question of mass. I'd be interested to know the results though. Of course the mass will vary with the absorption and that will vary with material. I believe that paper or fabric will take more C37 than aluminium.
Good luck with your experiment. Keep us informed.
7V said:
Hi Steve,
Of course it's not solely a question of mass. That's just the most common concern that I'm hearing about.
Concerns of cost, irreversibility and whether or not this material will make your drivers sound like a violin are out of my control. By the way, a violin can sound horrible in the wrong hands,. So, it depends on how you use this instrument once it's modified. Imagine tring to put a nail in with the claw end of the hammer.
OK.. for those of you that just became enlightened by the propper use of a hammer, please click on the little "x" in the upper right hand corner of your screen (this includes my ex-wife)
Another parameter that would seem to be of interest would be the rigidity imparted through the application of this material. Yeah... That's pretty easy to measure too. Let's see. Uhhm??? How much force/cm2 (weight) is required to cause a specific amount of compression for each of these tweeters? Hmmn? Ideally, I guess, I'm looking for the same response that I would get from an egg shell. the dome should be so rigid that it should crack instead of deflecting and there should be zero mass. Sheesh!!! This is getting too complicated, I think that I'll just go for it and listen to the results. WAIT!!! Should I apply C37 to my ear drum before I listen?
Don't be concerned. By the time you've thinned it down (I use 50% White Spirit) the mass added will be minimal.kensetsu said:
I inhale the stuff.
DISCLAIMER: not really - don't try this at home - I cannot be held responsible - etc., etc.
Here's a couple of possible cone stiffiners that you could try besides PVC wood glue.
PVC pipe dissolved in the priming fluid used to join it.
Polystyrene dissolved in acetone.
Shellac.
Super glue (may be had to apply, but it is incredibly stiff)
(SY's safety warning applies post #50)
PVC pipe dissolved in the priming fluid used to join it.
Polystyrene dissolved in acetone.
Shellac.
Super glue (may be had to apply, but it is incredibly stiff)
(SY's safety warning applies post #50)
Dazzzla said:Here's a couple of possible cone stiffiners that you could try besides PVC wood glue.
PVC pipe dissolved in the priming fluid used to join it.
Polystyrene dissolved in acetone.
Shellac.
Super glue (may be had to apply, but it is incredibly stiff)
(SY's safety warning applies post #50)
Actually, my favorite stiffeners at this time are Kate Beckinsale and Catherine Zeta-Jones.
Later, Nick
P.S. Just messing with you guys. Sometimes we all get too serious.
If I could find a sure fire cone treatment for JBL 2226's that would both damp the cone somewhat between, say 250hz-1Khz and make it moisture resistant *without* adding significant mass, I'd be very interested. Of course, considering their price, doing much in the way of experimentation is not really an option for me, and I'd be wary of anything that dramatically either stiffens or softens the cone or changes the mass much because there's the risk of deteriorating the sound of or making less reliable what is basically a very good high power woofer that just happens to miss sounding great in the mids by having what I think of as some low level excess 'liveliness' or resonance in the mids that compromises (I believe) its ultimate inner detail potential somewhat. I suspect the glass fiber here. Something that also insulates the paper/glass fiber cone against humidity changes (or actual liquids) would seem to be a significant net positive (I would paint both sides of the cone in this case). For my current application, a very slight lowering of the cone's hf rolloff would be acceptable (say up to 10%). And, given that I'd want to treat six of these drivers for my basement blasters at once, I'd need an extra special discount on C37 (which is about the only stuff I'd be willing to trust without further investigation at this point) to be able to afford to do them all🙂
This probably doesn't directly relate, but I was trying to make my own turntable mat for a while using such things as super thin felt glued onto bubblewrap with rubber cement or various other flexible adhesives added to the interstices of the bubblewrap for extra 'damping' and elimination of any possible 'crinkly' characteristic, and I found that it was easy to add plasticky colorations to the sound this way (although I was able to fabricate mats that worked well otherwise) where I felt the coloration actually deteriorated the overall sound quality although detail and punch was improved over the original felt mat (Linn Sondek). What I finally settled on that gave good damping and a neutral sound quality in this case was a thin sheet of sorbathane which I use to this day (although fuzz and dust stick to it like mad, necessitating occasional removal and a thorough wiping down on both sides with a damp rag). But that taught me some lessons about merely slathering on material since it might accomplish some goals but add undesirable colorations as side effects, and, unlike with a turntable mat, as others have noted, most such changes to speaker cones are probably irreversible.
This probably doesn't directly relate, but I was trying to make my own turntable mat for a while using such things as super thin felt glued onto bubblewrap with rubber cement or various other flexible adhesives added to the interstices of the bubblewrap for extra 'damping' and elimination of any possible 'crinkly' characteristic, and I found that it was easy to add plasticky colorations to the sound this way (although I was able to fabricate mats that worked well otherwise) where I felt the coloration actually deteriorated the overall sound quality although detail and punch was improved over the original felt mat (Linn Sondek). What I finally settled on that gave good damping and a neutral sound quality in this case was a thin sheet of sorbathane which I use to this day (although fuzz and dust stick to it like mad, necessitating occasional removal and a thorough wiping down on both sides with a damp rag). But that taught me some lessons about merely slathering on material since it might accomplish some goals but add undesirable colorations as side effects, and, unlike with a turntable mat, as others have noted, most such changes to speaker cones are probably irreversible.
When i was doing Pro PA, we as a matter of course always treated the cones (both sides) with puzzlecoat and the baskets with duct-seal -- JBLs, Audax, Celestion. The puzzlecoat could more be termed water resistant than water proof, but we did it to improve the sound.
dave
dave
I deleted the original content of this post because I just noticed that I posted something similar not too long ago in this thread.
Sorry🙂
Sorry🙂
Violin varnish
Some of the traditional violin varnishes are difficult to make, and potentially very dangerous.
Some of them involves heating linseedoil and rosin, you have to keep it at the right temperature, take it off the heat at just the right moment (heating too long and you have made linoleum, too short time and it will never harden).
Before it cools down you have to dilute it with turpentine, if it cools to much before you add tupentine it will just harden to a glasshard mass that is impossible to dissolve, if you add the turpentine too early, it will explode and cover everything(including yourself) with a sticky burning substance that will be glass hard when it cools.
Some of the varnishes also include other resins, like amber(verrrrry expensive).
I don`t know how the C37 varnish is made, but if it is made this way....
Regards,
Peter
Some of the traditional violin varnishes are difficult to make, and potentially very dangerous.
Some of them involves heating linseedoil and rosin, you have to keep it at the right temperature, take it off the heat at just the right moment (heating too long and you have made linoleum, too short time and it will never harden).
Before it cools down you have to dilute it with turpentine, if it cools to much before you add tupentine it will just harden to a glasshard mass that is impossible to dissolve, if you add the turpentine too early, it will explode and cover everything(including yourself) with a sticky burning substance that will be glass hard when it cools.
Some of the varnishes also include other resins, like amber(verrrrry expensive).
I don`t know how the C37 varnish is made, but if it is made this way....
Regards,
Peter
Anyone try dope for model airplanes?
What substances can be dissolved in acetone to produce a good coating material?
Tom
What substances can be dissolved in acetone to produce a good coating material?
Tom
I keep getting logged out if I type long messages. So I will explain this in sections.
First of all, just pure mass, spring physicsa will explain the faults that would occur if additional coating is applied without precise method to maintain predictable mass and stiffness distribution.
There will be differences, but the results would be unpredictable. I think everyone that has or has not tried this would not do it on expensive speakers because the quantifiable results are not predicatable.
First of all, just pure mass, spring physicsa will explain the faults that would occur if additional coating is applied without precise method to maintain predictable mass and stiffness distribution.
There will be differences, but the results would be unpredictable. I think everyone that has or has not tried this would not do it on expensive speakers because the quantifiable results are not predicatable.
I'm not considering using $200 drivers.
I do have some old drivers with ripped cones and it would be educational to recone and experiment on them.
Tom
I do have some old drivers with ripped cones and it would be educational to recone and experiment on them.
Tom
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