That doesn't make much sense to me. That limits cone materials to things that are solution processable. And it assumes that every designer's goal for a cone is similar. And that's not true- some want a slow, controlled rolloff at the high end, others might want an extended top at the expense of sudden breakup- which can easily be dealt with in the crossover.
SY said:
Yes, sorry. I just assume that we're all talking full-range drivers. Of course we're not.
What is "solution processable"?
Steve
Sorry, jargon. It means that a material is soluble in something and can be put where you want it by painting (or similar process), then drying/curing.
Flavouring Coatings....
Umm, what kind of Permatex ? - I went to the Permatex site and they list quite a range of products.
Scanspeak - do you mean that clear, sticky, never drying stuff ?.
My KEF 8" drivers and 4" mids have a quite thick, dry plastic like coating on them.
This works very well to make the cones quiet in them selves - rubbing a fingernail on them produces a very dull scratching sound, unlike typical paper cones that make a loud harsh scratching sound when rubbed.
This coating also seems to very much reduce transmission through the cone, and stops the cones making their own sound.
I have tried white (dries clear) pva glue on cones in the past, and this did a very good job of stiffening the cone, and also damping the cone.
Probably pva glue with a lossy coating (like the Kef coating) on top would be very good for woofers.
Care would be needed with mids to avoid over-killing them, but the coating is quite thick on the Kef mids.
I have also tried thinning and painting latex on a cheap mid, and this dulled it quite nicely too.
Eric.
Hello Sy,SY said:
Umm, what kind of Permatex ? - I went to the Permatex site and they list quite a range of products.
Scanspeak - do you mean that clear, sticky, never drying stuff ?.
My KEF 8" drivers and 4" mids have a quite thick, dry plastic like coating on them.
This works very well to make the cones quiet in them selves - rubbing a fingernail on them produces a very dull scratching sound, unlike typical paper cones that make a loud harsh scratching sound when rubbed.
This coating also seems to very much reduce transmission through the cone, and stops the cones making their own sound.
I have tried white (dries clear) pva glue on cones in the past, and this did a very good job of stiffening the cone, and also damping the cone.
Probably pva glue with a lossy coating (like the Kef coating) on top would be very good for woofers.
Care would be needed with mids to avoid over-killing them, but the coating is quite thick on the Kef mids.
I have also tried thinning and painting latex on a cheap mid, and this dulled it quite nicely too.
Eric.
It's sold as an undercoating compound at our local auto parts store.
What's the base cone material of the KEFs you have? It would be interesting to analyze what the purpose of the coating is.
I doubt that the PVA you're using is stiffening anything, unless your cones were really floppy. It will certainly add mass (which may or may not be a good thing) and may be useful for damping and modifying breakup modes (which may or may not be a good thing). Your observation about "dulling" is, I'd guess, spot-on. And... it may or may not be a good thing.
I'm amazed i've missed this thread till now....
On C37. It talks like snake oil, but i've heard enuff from people i respect to be interested in giving it a try if some ever comes my way (just don't ask me to pay for it).
Dammar is in the same "family" as C37, a natural varnish type material. I've got a couple bottles but haven't tried it yet. It gets good press on the FR forum...
The stuff on KEF drivers is black. IMF & Fried both found it wasn't enuff and further damped their B110s.
The stuff i have lots of experience with -- 25+ years -- is PuzzleCoat (a brand name that probably no longer exists). This is a PVA substance (Mr Feedback has already mentioned thinned wood glue) that is already thinned a bit and is specifically formulated for coating stuff (ie puzzles). I have a page on the stuff on my web-site (note: i just opened the podgy brand and it was way too thick -- don't know whether it comes like that or 2 years on the shelf was too much).
I have rarely had a bad result on a paper cone. Caution must be taken thou as it will degrade the top end to some extent if used excessively (ie i have some 15" co-axes that now need a midrange). Bass drivers can usually handle 2 or 3 coats back & front, full ranges a thin coat or 2 on the front (i've used it on FE103A and RS 40-1197 with improvement in each case). I've even used it on paper cone tweeters and paper domes mids (Philips) with good results.
It stiffens, damps, and ,often forgotten, it makes the cone more opaque to sound passing thru the cone.
I've also used it on plastic cone drivers (KEF B200 & B110 in particular) and some other plastic cone drivers. It has also proven helpful with the MCM 5" aluminum MC 55-1855 where it damped down some HF ringing and allowed me to get away with no LP on the XO. I have somewhere a study done by a fellow with the same drivers and he tried some 4 different coatings and the PuzzleCoat came out ahead.
Also one has to consider the possibilities of non-uniform application. As well as being a good stiffener/damper coating it is also usful for fixing ripped cones. I have an experiment going with a set of 12" FR w whizzer where i gave the inner cone more coats than the outer cone (and used some sparkly PZ for the whizzer 🙂). I'll let you know how it worked out once i get my big baffles assembled.
dave
PS and a name i've heard bandied about, but have never gotten my hands on is Lord's BL100 ... anyone want to be point on splitting up a 5 gallon pail?
On C37. It talks like snake oil, but i've heard enuff from people i respect to be interested in giving it a try if some ever comes my way (just don't ask me to pay for it).
Dammar is in the same "family" as C37, a natural varnish type material. I've got a couple bottles but haven't tried it yet. It gets good press on the FR forum...
The stuff on KEF drivers is black. IMF & Fried both found it wasn't enuff and further damped their B110s.
The stuff i have lots of experience with -- 25+ years -- is PuzzleCoat (a brand name that probably no longer exists). This is a PVA substance (Mr Feedback has already mentioned thinned wood glue) that is already thinned a bit and is specifically formulated for coating stuff (ie puzzles). I have a page on the stuff on my web-site (note: i just opened the podgy brand and it was way too thick -- don't know whether it comes like that or 2 years on the shelf was too much).
I have rarely had a bad result on a paper cone. Caution must be taken thou as it will degrade the top end to some extent if used excessively (ie i have some 15" co-axes that now need a midrange). Bass drivers can usually handle 2 or 3 coats back & front, full ranges a thin coat or 2 on the front (i've used it on FE103A and RS 40-1197 with improvement in each case). I've even used it on paper cone tweeters and paper domes mids (Philips) with good results.
It stiffens, damps, and ,often forgotten, it makes the cone more opaque to sound passing thru the cone.
I've also used it on plastic cone drivers (KEF B200 & B110 in particular) and some other plastic cone drivers. It has also proven helpful with the MCM 5" aluminum MC 55-1855 where it damped down some HF ringing and allowed me to get away with no LP on the XO. I have somewhere a study done by a fellow with the same drivers and he tried some 4 different coatings and the PuzzleCoat came out ahead.
Also one has to consider the possibilities of non-uniform application. As well as being a good stiffener/damper coating it is also usful for fixing ripped cones. I have an experiment going with a set of 12" FR w whizzer where i gave the inner cone more coats than the outer cone (and used some sparkly PZ for the whizzer 🙂). I'll let you know how it worked out once i get my big baffles assembled.
dave
PS and a name i've heard bandied about, but have never gotten my hands on is Lord's BL100 ... anyone want to be point on splitting up a 5 gallon pail?
One more "big" benefit of puzzlecoat -- it makes the driver cone shiny (even the matte stuff, but to a lessor extent).
The pic is some 12" Philips (note: the ductseal on the basket i do not consider optional -- i have yet to find a speaker that doesn't benefit from it (althou i have seen some where it would be difficulat to apply (ie the PHY-HP))).
Two things i didn't mention in my previous post... 3 coats front & back on a woofer is enuff to lower Fs & sensitivity, And another treatment i've seen but not tried is the application of a layer of metal foil (aluminum in the example i've seen -- but i've talked to an artist friend who says there are quite a few other possibilities -- gold leaf anyone?).
dave
The pic is some 12" Philips (note: the ductseal on the basket i do not consider optional -- i have yet to find a speaker that doesn't benefit from it (althou i have seen some where it would be difficulat to apply (ie the PHY-HP))).
Two things i didn't mention in my previous post... 3 coats front & back on a woofer is enuff to lower Fs & sensitivity, And another treatment i've seen but not tried is the application of a layer of metal foil (aluminum in the example i've seen -- but i've talked to an artist friend who says there are quite a few other possibilities -- gold leaf anyone?).
dave
Attachments
The Kefs B110 Mids and B200 8" cones are some kind of black plastic material, with a clear pva glue like coat on both sides, including the center domes.SY said:
The domes are not raucous like most when rubbed, and the cones are pleasantly dead too when rubbed.
The cones are also very lossy to sounds from the rear.
Pictures - thanks Dave
I found Pva coating a paper 10" worked very well to stiffen the cone and quieten it - this can be overdone of course, and I found one very thinned coat, and when half dry another two coats of thicker mixture worked a treat.
Eric.
MAJOR SAFETY WARNINGMy apologies for not being explicit enough about safety. When you're formulating or using coatings that have a volatile solvent base, be absolutely sure that you've got adequate ventilation and lots of moving air. DO NOT USE MOTORIZED APPLIANCES unless they have motors specifically designed for these environments. Explosions and fires are Bad Things. So is brain damage.Don't use any commercial stuff that doesn't include or have available the mandatory MSDS. If you have any doubts about what you're doing, don't do it!
mrfeedback said:
made of bextrene as Sy says. Now i think back a bit, the additional coating that Bud Fried used was black.
dave
I would recommend painting a smiley face on the dustcap with the yellow paint they use to make the lines on the road. This causes the listener to smile when they listen. Smiling produces endorphins. Endorphins make you happy. Speakers tend to sound much better when you are in a good mood. And it really cleans up the midrange.
Violin Varnish and C37
It occurs to me that, as C37 was originally developed (I believe) as a violin varnish, we could check other violin varnishes to see if there's a less expensive way to achieve similar results.
Typing "violin varnish" into Google yield promising results.
Steve
It occurs to me that, as C37 was originally developed (I believe) as a violin varnish, we could check other violin varnishes to see if there's a less expensive way to achieve similar results.
Typing "violin varnish" into Google yield promising results.
Steve
It will give an effect to paint ANY tweeter with ANYTHING. Whether the effect is a good one or not is always open to question.
doping paper cones
In regards to "doping" cones attempting to add stiffness, has anyone tried model airplane dope? After all, that is the original source of the term "dope" in several of its meanings, (dope for drugs because breathing the toluene fumes gets one "high"), and it has been the treatment for airplane wing fabrics for nearly 100 years.
Just wondering...actually, I'll give it a try on some of the parts express $0.87 & post MHO results.
In regards to "doping" cones attempting to add stiffness, has anyone tried model airplane dope? After all, that is the original source of the term "dope" in several of its meanings, (dope for drugs because breathing the toluene fumes gets one "high"), and it has been the treatment for airplane wing fabrics for nearly 100 years.
Just wondering...actually, I'll give it a try on some of the parts express $0.87 & post MHO results.
Hi Steve,
Your results are pretty reassuring. To tell you the truth, I'm sitting on some new in the box Dynaudio T330D Esotar tweeters and the thought of possibly ruining them is scary. Well... I'll probably go for it anyway and compare them with my other pair. Do you have any suggestions on application methods?
Later, Nick
Your results are pretty reassuring. To tell you the truth, I'm sitting on some new in the box Dynaudio T330D Esotar tweeters and the thought of possibly ruining them is scary. Well... I'll probably go for it anyway and compare them with my other pair. Do you have any suggestions on application methods?
Later, Nick
Hi Nick. Just remind me, are you thinking of using C37 or some type of substitute? Also, what material is the T330D?kensetsu said:
I use C37, brush painted onto aluminium. I have to be careful of dust when as the lacquer dries but this is an aesthetic consideration, not acoustic. I use three coats with three days between them. You could audition between each coat.
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