Goodmans speakers used their doping compound 'plastiflex'...making it sound like a proprietary compound.
It was just PVA woodglue...
Ive done the same, just use the minimum you can, as there's no remedy for too much dope.
🙄
It was just PVA woodglue...
Ive done the same, just use the minimum you can, as there's no remedy for too much dope.
🙄
not sure about the PVA glue
I know some people have used it a lot
but its not very strong, and I fear it gets crisp, and causes small invisible cracks in the paper fibers
I know some people have used it a lot
but its not very strong, and I fear it gets crisp, and causes small invisible cracks in the paper fibers
Save your old TP rolls and experiment with PVA, epoxy, urethane and the aforementioned MSS. That way you can test mass increase and with a simple squeeze, get an idea of the stiffening properties.
That seems very watery. I would use that only as a primer. I would be afraid of cone deformation if used in multiple coats.
The water is a solvent, it evaporates. Damping occirs because you are creating a boundary with a change in impedance.
dave
Not very strong? Have you ever tried breaking a properly PVA glued wooden box? Where does it break?
I also find it rather flexible when dry, more like a plastic. Not to mention that if you do not use enough it will just leave air gaps in between some dry "pillars", no breaking in the glue itself. Think you mean that it will pull the paper fibers apart when drying, but paper is just wood in a more processed form, diluted PVA glue will mix just as well with paper as regular wood. And since it is diluted it will work like the undiluted stuff just on a smaller scale. PVA glue will stiffen the structure between the paper fibres, making it much more rigid. Just like epoxy works great for other things like carbon fibre, or fibreglass. The glue is just a bond locking the fibres together, as well as giving the fibres a "shield", the fibres provide strength just like before, they are just more connected, therefore the total structure is much stronger.
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Cone stiffening should not help much for low end performance, but it lifts upper end and makes a resonance peak.
http://www.klippel.de/fileadmin/kli...ture/Papers/KLIPPEL_Cone_Vibration_Poster.pdf
http://www.aes.org/e-lib/browse.cfm?elib=3251
This is the real snake oil - Ennemoser C37 lacquer! http://www.ennemoser.com/speakers.html Even amplifiers get better with it!
This guy believes in pure paper http://www.mother-of-tone.com/speaker.htm
http://www.klippel.de/fileadmin/kli...ture/Papers/KLIPPEL_Cone_Vibration_Poster.pdf
http://www.aes.org/e-lib/browse.cfm?elib=3251
This is the real snake oil - Ennemoser C37 lacquer! http://www.ennemoser.com/speakers.html Even amplifiers get better with it!
This guy believes in pure paper http://www.mother-of-tone.com/speaker.htm
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yes, exstremely strong when properly done
but breaks very easily if joints are not tight(accurate)
and falls apart almost by itself if no pressure have been used
and btw, there is a reason why 2-component epoxy glue is preferred for hardwood
but maybe we should destinguish between small light cone fullrange drivers, and bigger heavy cone woofers
Paul at Goodsoundclub.com wrote about how every expert used to have his own secret formula for cone stiffening. In the end, Paul writes, it is better to choose a speaker that sounds good from the beginning, instead of ruining a lot of speakers like he did over the years.
I also believe paper sounds most natural, but it has no detail above ~400-1000 Hz. For that I need metal diaphragms, but those won't match my paper cones in sound. Very annoying situation, because I have excellent paper woofers from JBL and SABA that I may not be able to use. Maybe I should use Klipsch woofers with aluminum/magnesium alloy cone.
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maybe not much, but enough to make the difference
Attachments
Tinitus...could you explain those pics a bit for me? What was your goal here with this three-way...and did you try and stiffen the MF paper cone as well? Looks like it to me.....
I will try answer all you want to know, sure
midrange is old Focal
I am told the cone is a two layer Kevlar sandwich
and as such very stiff
so I have 'enabled' it with a bit careless roof tar coating 😀
maybe I will give it a bit more
but it smells horrible while drying up, and it's very toxic
works exstremely well tho
ahh, I see now what may look confusing
took off the dustcap first
that sounded better
removed that the original 'coating' paper below the dustcap
and decided to carefully peel off the rest, bit by bit
it was still very stiff, so still working well
and also sounding much better
first I wanted to coat it wit my good and proven roofing tar
but it's just so toxic
so I decided to use epoxy glue instead
and the cone is quite hard now
bass got more detailed
and midrange much cleaner
funny experience with music today
I have old second hand Johnny Winter CD
with some of the older 'country style' tunes
before coating it was unbareable
and really hard to hear the rythm, or impossible
big surprice when I put it on today
it now sounded very different, and real easy to hear the 'rythm'
I should probably also adjust crossover now
but whatever, for now it's ok 🙂
I have used thinned shellac in the past on paper cones. Not for stiffening, but to diminish the effects of changing humidity. Doesn't seem to cause any problems. Easy thinning and clean up with ordinary alcohol.
At one point the question of the longevity of puzzlekoat (PVA) was questioned, I have units in the field done in the late 70s that are fine today (surrounds needed redoing thou) and large woofers used in subwoofers that date to the latter years of the last century that are still in regular use.
dave
dave
OK...that part I get...but what were you trying to do here? Tame some break-up of the woofer, and take some of the harshness out of the MF cone?
What I mean, is what were these speakers doing that you didn't care for....and did this "enabling" work for you? And how does one ensure both speakers receive an equal and proportional level of treatment.
Don't get me wrong...I love your free-style approach🙂
I've used some of the aerosal spray-on undercoating mix used for automotive applications. $5.00 U.S. a can. It has a easy to brush on consistency with a foam brush and can be built up as required.
There are many here on DIYaudio that would require measurements and data prior to supporting such tweaks...I am not one of them....but it would be interesting to measure before and after and see if, in fact, such tinkerin' has any objective result...positive or negative....
I have always been quite skeptical of the whole enabling thing, and yet, I remain open to the experiences of others.
Your enabling process on the other hand seems right up my alley...I love paper cones and MF domes as found on some of the Philips MF drivers of the late 70s and 80s...which always seem a tad bright in comparison to the later silk dome variants. Hmmm wonder if I should attempt treating them.
Thanks for sharing your particular experiences....