Mag,
Please accept my sincere apology for my off-base comments I made yesterday.
I would much rather be respectful to and learn from all who come to these forums.
Especially to the ones who hold valuable information.
G
Please accept my sincere apology for my off-base comments I made yesterday.
I would much rather be respectful to and learn from all who come to these forums.
Especially to the ones who hold valuable information.
G
I used lacquer on carbon veil. This produced the light weight that I was looking for (8mg cm-2). I made some test samples with a laminate of carbon veil/tracing paper/epoxy and it weighed 23mg cm-2.
Thanks for that (#461), C. *S* And I own up to going 'off subject' way too much, a terrible precedent to display. Since I've become the default 'moderator' of this forum, I should display a bit more decorum as well. Not that in the sense that everything needs to become stiff and formal. I'm not like that IRL, nor do I expect anyone to go against their grain (so to speak) either.
Just the usual reminder that since we can't see each other, there's no way to monitor another's response to what might be construed as an personal faux pas. If I step on your hands or I mangle your feet (to quote the late Lou Reed), let me know immediately and publicly. I refuse to be act the troll, and I would like anyone here to refuse it as well...
*Jerry kicks the soapbox back into the void...*
Now, where were we? *G*
It shattered....? Like a dropped light bulb, or just cracked as would an egg? I can see where lacquer would cause that latter to occur. And by 'carbon veil', you're referring to that material that you included in your 'care package' to me?
The lightness of that first combination is intriguing. I'm assuming a spray application...
Just the usual reminder that since we can't see each other, there's no way to monitor another's response to what might be construed as an personal faux pas. If I step on your hands or I mangle your feet (to quote the late Lou Reed), let me know immediately and publicly. I refuse to be act the troll, and I would like anyone here to refuse it as well...
*Jerry kicks the soapbox back into the void...*
Now, where were we? *G*
It shattered....? Like a dropped light bulb, or just cracked as would an egg? I can see where lacquer would cause that latter to occur. And by 'carbon veil', you're referring to that material that you included in your 'care package' to me?
The lightness of that first combination is intriguing. I'm assuming a spray application...
Yes, cracked like an egg, but around the whole circumference near the apex.
Even though carbon fiber has high tensile strength it is very brittle. The speaker was dropped, landed magnet first naturally, and the impact shatter the cone. 😱
Same stuff I sent you as a sample. I think I still have three yards of it.
It was tricky to coat with lacquer since it is so porous. Ended up laying it flat on wax paper and brushing over it. It was much easier to laminate on paper, using the same technique.
After the lacquer coat...did your form it while wet, or after it dried? The second seems more reasonable, but I'd think the lacquer would make it stiff. That would explain the brittleness...
Forming wet, however, could degenerate into a sticky mess rather abruptly. Laminating the paper seems a good alternative....and eliminates the 'shatter factor'. *G*
Starting a new p.g. installation tomorrow, so my projects go on hold for awhile. I'll look over your shoulder, if you don't mind posting the process. *S* Always good to see alternatives, different approaches.
Forming wet, however, could degenerate into a sticky mess rather abruptly. Laminating the paper seems a good alternative....and eliminates the 'shatter factor'. *G*
Starting a new p.g. installation tomorrow, so my projects go on hold for awhile. I'll look over your shoulder, if you don't mind posting the process. *S* Always good to see alternatives, different approaches.
For the lacquer to adhere to the carbon fiber it has to dry completely. This took about a day or so because the lacquer is trapped below the carbon fiber matrix. Plus, I used "brushing lacquer", which has a "retardant" to extend drying time.
Laminating with paper was a much easier method because the paper absorbs the lacquer. This made application and drying easier. A better end product resulted being smoother, more durable, and easier to form into a cone. This version weighed 10 mg cm-2, only 25% more.
Spraying the lacquer would probably be a better method, once you perfected it.
Good luck with your install...
Laminating with paper was a much easier method because the paper absorbs the lacquer. This made application and drying easier. A better end product resulted being smoother, more durable, and easier to form into a cone. This version weighed 10 mg cm-2, only 25% more.
Spraying the lacquer would probably be a better method, once you perfected it.
Good luck with your install...
No hard feelings I thought it was so ridiculous I didnt take it personally. 🙄 I just think there may be other ways of doing things again it depends on the persons goals.
Cool, glad to hear. I'm open to any ideas, feedback or whatever you have, anytime. 😉
...and I'm happy to see the above. *BS* Cumbaya not necessary...and a fire to throw the aforementioned speaker cabinets wouldn't have lasted long enough for 'smores. 😉
C., harking back to my college art dept. 'daze' *L*, I remembered Japanese rice papers. We know them typ. as the material used on lanterns, both 'cheapie banal' and 'high style' varieties. A few of them are marvelously light, translucent...some with a random pattern. That, and the drafting vellums still available to us 'old school' types that still know their way around T-squares and such (although I prefer my drafting machine...less of hassle to use...). I was wondering if you've run into them, or had thought of using one or the other. Could make for a stylish combination with the carbon veil. That, and using lacquer to create cones makes it almost edge into 'functional art'.
Perhaps a new approach on the old SAF, for those subject to that...*G* 'Ell, I might 'go there'.
I picked up a sheet of 'Tiziano' paper; 10 mil, but has an slight knubbly texture that I thought was interesting, reminiscent of the texture seen on some conventional speaker cones. Besides, it's acid-free paper make by an Italian firm that's been making paper since the 1300's. Nothing like using a 'classic'....besides, it's ultramarine in color, and y'all have noticed I tend to like cones other than black, silver, or white...*G*
The vellum stock I have on hand is 3.5 mil thick, and it's a pretty basic variety. There's better available.
...and then there's the mylar sheets...one can go transparent or translucent, but what a plastic cone would sound like is an open question...
*L* I really should figure out how to make a 'hot-swappable' cone. Become the 'Baskin-Robbins' of diy audio repro. "31 flavors? Not enough!" *LOL* "Don't like that one? Try this one. Also available in 'camo', for you 'outdoorsy' types."
Don't laugh too much, it can be done. How do you think they make those 'camo' gunstocks? It's a 'dipping' process, called water transfer printing. If you can dip it, it can be printed...although the artwork available can be pretty ghastly....skulls and all sorts of the like.
I'd like to see a pattern that would change with the frequencies that the cone is reproducing. Now that could be pretty mesmerizing....and a 'real time' display in 3D. And likely requiring something toxic to make it work....
"Don't touch the speakers...."
"My fingers are melting!"
"Told you...where should I send your body....or what's left?"
(*Sheesh* Another mess to mop up....*sigh*)
Sorry...another 'off subject' ramble...😉
C., harking back to my college art dept. 'daze' *L*, I remembered Japanese rice papers. We know them typ. as the material used on lanterns, both 'cheapie banal' and 'high style' varieties. A few of them are marvelously light, translucent...some with a random pattern. That, and the drafting vellums still available to us 'old school' types that still know their way around T-squares and such (although I prefer my drafting machine...less of hassle to use...). I was wondering if you've run into them, or had thought of using one or the other. Could make for a stylish combination with the carbon veil. That, and using lacquer to create cones makes it almost edge into 'functional art'.
Perhaps a new approach on the old SAF, for those subject to that...*G* 'Ell, I might 'go there'.
I picked up a sheet of 'Tiziano' paper; 10 mil, but has an slight knubbly texture that I thought was interesting, reminiscent of the texture seen on some conventional speaker cones. Besides, it's acid-free paper make by an Italian firm that's been making paper since the 1300's. Nothing like using a 'classic'....besides, it's ultramarine in color, and y'all have noticed I tend to like cones other than black, silver, or white...*G*
The vellum stock I have on hand is 3.5 mil thick, and it's a pretty basic variety. There's better available.
...and then there's the mylar sheets...one can go transparent or translucent, but what a plastic cone would sound like is an open question...
*L* I really should figure out how to make a 'hot-swappable' cone. Become the 'Baskin-Robbins' of diy audio repro. "31 flavors? Not enough!" *LOL* "Don't like that one? Try this one. Also available in 'camo', for you 'outdoorsy' types."
Don't laugh too much, it can be done. How do you think they make those 'camo' gunstocks? It's a 'dipping' process, called water transfer printing. If you can dip it, it can be printed...although the artwork available can be pretty ghastly....skulls and all sorts of the like.
I'd like to see a pattern that would change with the frequencies that the cone is reproducing. Now that could be pretty mesmerizing....and a 'real time' display in 3D. And likely requiring something toxic to make it work....
"Don't touch the speakers...."
"My fingers are melting!"
"Told you...where should I send your body....or what's left?"
(*Sheesh* Another mess to mop up....*sigh*)
Sorry...another 'off subject' ramble...😉
I have some 5 mil rice paper called "masa rice". The drafting vellums are what I used for backing the carbon fiber veil. One is 1 mil and the other is a cotton 2 mil called "clear print". Both worked good.
The resin (lacquer) will then about double the weight. Thought about more advanced methods like vapor deposition (polymethyl methacrylate).
The carbon fiber veil weighs nothing...floats down like a feather when you drop it...
Thought about impregnating the cone with [piezo crystals] to generate a charge when sounds waves passed over.
That might light up your colored light emiting cone... 
O.T. Doing some bluegrass pickin Saturday. The guys who hosts the"Ol Hippy Bluegrass Show" WQTE fm 95.3 is the group I hang with.
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I think this would not be the optimal way to build these drivers. Lighter is not better in this case actually the weight of the cone is irrelevant. to a degree dont take it verbatim but the cones weight does not really come into account. The whole weight of the cone is calculated from the weight of the voice coil not the cone. This is not opinion but fact
I really think this driver type is actually all about the motor not the cone. The cone is easy to make and get good results this is the easy part. The motor in this driver is where all the magic happens as Jerry can note. If you wan to get metaphorical think of this driver as a true source in the sense that the cone is merely a window allowing you to see the motor fully.
That's why I made the cones out of a light material, a 5 inch (13 cm) diameter cone @ 72 degrees has more surface area than a 10 inch speaker. With a light material (on the order of 10mg cm-2) it ends up weighing about 4 g, which was what I was shooting for. My light cones had much higher efficiency, and a more balanced frequency response. Walsh cones need to have a good high freq response because of their omni dispersion (IMO).
Guys..."By Jove, I think you've got it!" *L*
IMHO, a light(er) cone attached to a robust vc is the configuration of choice. The cone has to 'tough enough' to handle the spl currently expected in a modern loudspeaker, but light enough to generate the higher frequencies at the apex of the cone. Always a trade-off, to be sure, but modern materials certainly should able to be selected to approach this ideal as much as practical. Vapor deposition of a stiffening agent could be a terrific way to make a flimsy material perform, but the equipment needed to apply such isn't in my diy universe, but is probably worth a look as to what & how....
As for cone weight, I remember reading Somewhere that the weight of a Walsh F cone was upwards of 200 grams. Now, that translates to 7 ounces. Assuming that included the vc, that's a lot of mass to move. Even half of that still seems like pushing a brick around with a feather...quickly..... But when you stop and look at the size of that cone, with all it's 'treatments' applied, And the vc...
HHR is duplicating the Ohm's magnet structure; 1.2 pounds of alnico, a 10+ pound magnet structure. That's 'goosing' that cone with a lot of Gauss, guys. Damn! *LOL*
C, re your #474 post...absolutely right. Large areas on a conical surface. They may not 'hear' as loud as a typ. speaker, but that's follows from the radiation pattern. The energy is being dispersed differently. Efficiency is important, but 'robustness' is key as well. Since we're driving an apparently small cone with a large surface area, the more 'horsepower' that can be delivered fast enough to that apex is the grail goal.
Ultimately, I think Glorocks suggested the means to the end. A 'purpose built' motor, coupled to a properly configured cone, with a surround that soaks up as much of the base's motions (transverse, pistonic, 'bell modes', and whatever else a cone can be capable of creating 'down there')....
Smells like success to me. 😉 But that's still conjecture on my part. *G*
Quote: "Doing some bluegrass pickin Saturday. The guys who hosts the"Ol Hippy Bluegrass Show" WQTE fm 95.3 is the group I hang with."
Sounds like good clean fun. *G* For us, Highland Brewery is having an open house starting at 5 today for their new facility, which will 10X their output.
It's about a 1/4 mi. away. I think I could crawl home without too much damage, unless I got run over. *L* Which is a possibility...with all the 'micro breweries' in the area, we're becoming the DUI center of NC, if you head count all the scooters on the street of late...50cc 'buzzers' are so lame...*L*
IMHO, a light(er) cone attached to a robust vc is the configuration of choice. The cone has to 'tough enough' to handle the spl currently expected in a modern loudspeaker, but light enough to generate the higher frequencies at the apex of the cone. Always a trade-off, to be sure, but modern materials certainly should able to be selected to approach this ideal as much as practical. Vapor deposition of a stiffening agent could be a terrific way to make a flimsy material perform, but the equipment needed to apply such isn't in my diy universe, but is probably worth a look as to what & how....
As for cone weight, I remember reading Somewhere that the weight of a Walsh F cone was upwards of 200 grams. Now, that translates to 7 ounces. Assuming that included the vc, that's a lot of mass to move. Even half of that still seems like pushing a brick around with a feather...quickly..... But when you stop and look at the size of that cone, with all it's 'treatments' applied, And the vc...
HHR is duplicating the Ohm's magnet structure; 1.2 pounds of alnico, a 10+ pound magnet structure. That's 'goosing' that cone with a lot of Gauss, guys. Damn! *LOL*
C, re your #474 post...absolutely right. Large areas on a conical surface. They may not 'hear' as loud as a typ. speaker, but that's follows from the radiation pattern. The energy is being dispersed differently. Efficiency is important, but 'robustness' is key as well. Since we're driving an apparently small cone with a large surface area, the more 'horsepower' that can be delivered fast enough to that apex is the grail goal.
Ultimately, I think Glorocks suggested the means to the end. A 'purpose built' motor, coupled to a properly configured cone, with a surround that soaks up as much of the base's motions (transverse, pistonic, 'bell modes', and whatever else a cone can be capable of creating 'down there')....
Smells like success to me. 😉 But that's still conjecture on my part. *G*
Quote: "Doing some bluegrass pickin Saturday. The guys who hosts the"Ol Hippy Bluegrass Show" WQTE fm 95.3 is the group I hang with."
Sounds like good clean fun. *G* For us, Highland Brewery is having an open house starting at 5 today for their new facility, which will 10X their output.
It's about a 1/4 mi. away. I think I could crawl home without too much damage, unless I got run over. *L* Which is a possibility...with all the 'micro breweries' in the area, we're becoming the DUI center of NC, if you head count all the scooters on the street of late...50cc 'buzzers' are so lame...*L*
Can't quote im on the phone but that's just it 🙂 Jerry it's not moving a mass. The speaker is creating waves not pistonic motion. Metaphorically you are creating waves in a pool not moving the pool. The voice coil is the only factor to weight the only pistonic motion. The most important thing is a motor that supplies the guass, and a voice coil which allows for efficiency and heat dissipation while maintaining low weight I built one on paper that weighted Like 2grams the whole "moving" mass would be like 4 grams. Basically right Just a different angle. The whole line above is from a conversation with German physics.
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I'm hip, Mags. The pistonic motion only comes into play when the cone base diameter reaches a certain point, where the waves 'break down', likely due to frequency (gone on the 'down low', to make a half-azed pun). And what you've posted is correct, although we could discuss voice coil 'mass' until we're exhausted by it. It seems to me that at the vc you're encountering 'resistance' to pistonic motion of the vc created by the shape of the cone. The cone, being a form of triangle in 3D, has immense resistance to creating waves, which would lead to the creation of heat in the vc, since it's having to get that cone excited....
But that's how I view it, imperfect/flawed as I may state the case....
...and I have immense respect for you going to the source for the answers....😉 I mean, I'd have a certain reluctance calling up GP for info. It's like going to the philosopher in his mountain hideaway and saying "Well, WTF, Really?!" *LOL*
Kudos, guy....*G*
But that's how I view it, imperfect/flawed as I may state the case....
...and I have immense respect for you going to the source for the answers....😉 I mean, I'd have a certain reluctance calling up GP for info. It's like going to the philosopher in his mountain hideaway and saying "Well, WTF, Really?!" *LOL*
Kudos, guy....*G*
I know your hip Jerry, and thanks for the complement. I never though of the vc as having to excite the cone I thought the vc heated up from not moving and the amount of current needed due to the inefficiency of omni's. could be a lot of things im sure.
*L* The vc is moving, but it's movement is constrained by a rigid cone (even with paper or the like) with different support at the surround, at least with what I've made. A typical speaker allows the cone to move freely, to 'push/pull' the air, creating the waveforms we hear. With a Walsh, we're creating waveforms in the surface of the cone, which excites the air about it.
It's 'inverting' the formula, so to speak. Doesn't strike me as ever being terribly efficient as the 'load' on the vc is so different than we're used to. Heat is the byproduct of stress in the system as we turn the volume up to raise the spl, such as is seen with a conventional speaker. But in the case of a Walsh, we're literally trying to 'squash'/stretch a cone to make it ripple on it's face....
*G* That may be an oversimplification of the situation, but I'm PUI (Posting Under the Influence...it was a good time @ the 'open house' of the HiWire brewery) so I wouldn't be surprised if my thoughts on the subject might seem a 'little obtuse'. But, be that as it may (sic), I'll still insist that the physics involved are different than we're used to. We're asking that little vc to work harder at it's 'new job', so stress/heat is the byproduct....
This is why I'm considering 'renovating' drivers from/for musical instrument equipment...designed for high loads, high power, big demands, all that...'volume to 11'. *L*
It's 'inverting' the formula, so to speak. Doesn't strike me as ever being terribly efficient as the 'load' on the vc is so different than we're used to. Heat is the byproduct of stress in the system as we turn the volume up to raise the spl, such as is seen with a conventional speaker. But in the case of a Walsh, we're literally trying to 'squash'/stretch a cone to make it ripple on it's face....
*G* That may be an oversimplification of the situation, but I'm PUI (Posting Under the Influence...it was a good time @ the 'open house' of the HiWire brewery) so I wouldn't be surprised if my thoughts on the subject might seem a 'little obtuse'. But, be that as it may (sic), I'll still insist that the physics involved are different than we're used to. We're asking that little vc to work harder at it's 'new job', so stress/heat is the byproduct....
This is why I'm considering 'renovating' drivers from/for musical instrument equipment...designed for high loads, high power, big demands, all that...'volume to 11'. *L*
At least two types of mass: total cone mass and unit mass. Total cone mass will determine the voice coil mass and EMF force needed to properly drive the cone mass. Unit mass (and cone stiffness) will effect acceleration (response to the imposed force).
I'm assuming one would want a wide-band and efficient loudspeaker. At least I do (since I use class A amps). The Walsh driver was intended to be wide-band device (full range).
I also want fast transient response (approaching electrostatic or planar).
In the real world; The basic cone parameters would be decided first (density, stiffness, and size). Then a voice coil mass could be determined. Lastly, a magnet structure capable of supplying the required force.
So, for a full-range and efficient loudspeaker, I want a high magnetic flux motor, but with a light voice coil, and a light, stiff cone to match.
Might not succeed as a commercial product, but with my current drive amp it works great.