I think the magic is in the first mm of the cone/voice coil (please interpret). Earl Geddes work on OB waveguides got me thinkin about all that...
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Assorted wanderings...
Quoting, "I think the magic is in the first mm of the cone/voice coil (please interpret). Earl Geddes work on OB waveguides got me thinkin about all that.."
I'll look into that, although magic is not something I'd hope for....H. Potter I'm not, and if I was, the world might look a bit different and I might not act so obvious or oblivious....😉
Aww, prefab surrounds? While I'm having so much fun? *sheeesh*L* Yeah, but most (if not all) are meant For compliance while my understanding is to minimize and stamp out all that oppose me...(ooops, wrong script, sorry...*G*)
BTB, there's a Newton's Cradle online (Utube, likely) made with bowling balls...big....don't get in the way, kids.... 😉 I didn't do it, honest, and our insurance co. would have a major fit...
I was just channeling the old song by Lee Dorsey...somedays just feel like that, y'know...(although the version by Devo is fun, too...*G*)
Quoting, "I think the magic is in the first mm of the cone/voice coil (please interpret). Earl Geddes work on OB waveguides got me thinkin about all that.."
I'll look into that, although magic is not something I'd hope for....H. Potter I'm not, and if I was, the world might look a bit different and I might not act so obvious or oblivious....😉
Aww, prefab surrounds? While I'm having so much fun? *sheeesh*L* Yeah, but most (if not all) are meant For compliance while my understanding is to minimize and stamp out all that oppose me...(ooops, wrong script, sorry...*G*)
BTB, there's a Newton's Cradle online (Utube, likely) made with bowling balls...big....don't get in the way, kids.... 😉 I didn't do it, honest, and our insurance co. would have a major fit...
I was just channeling the old song by Lee Dorsey...somedays just feel like that, y'know...(although the version by Devo is fun, too...*G*)
I try not to rely on magic, although it is hoped for.😉 The magic is in the genius of L. Walsh.
Prefab surrounds? While your having so much fun?
Yeah, why not? I did with no problem.
Walsh cones are no different from any other speaker cone, they produce sound with the same laws of physics, you can call them magical bending waves if you prefer...😎
Jerry replying to the comment you made about the speaker tightening up when you stiffened the spider. I remember I experimented with a loose end termination. All it did was act as a low pass filter and I heard boomy bass and nothing else. You might benefit from the same idea of a rigid connection. How is the connection made now? Just the inverted cone suspended by the surround?
Hi Mags. No, just trying to sell the idea of using a conventional surround. 
That is, unless you have something even better by now🙂
That is, unless you have something even better by now🙂
I dont but I was thinking a more solid connection could help if the cone is indeed suspended by the surround I think a better sound could be obtained from a silicone "o" ring acting as a surround. Really any materiel so long as its damping and relatively higher durometer.
Oh sorry, didn't read your questions close enough. We were referring to Jerry's prototype being terminated too rigidly.
I am trying to understand how the diy guys built these models. specifically at the end termination of the "surround". Can anyone include a diagram or a description? is it literally a normal speaker surround glue where the speaker is suspended in the air by this surround? or is there something I am missing?
Just like a conventional speaker in every sense. We all know that sounds great. Then, work outwards from there...
"...and I'm Back in Black!" *Loud guitars...*
I think I should just 'lurk' more often... 😉 Y'all seem to be doing Great without my interruption...*LOL*
OK, Gary, you drove me back to the patent. I could quote chapter and verse, but it does state repeatedly that the function of the surround is to support And terminate the waveform as best as practical to eliminate reflection back up the cone. This could be performed by the surround material selection itself or multiple routines of surround structure, damping material applied to the interior of the cone, or combinations of both with various approaches as to application.
A fascinating part (for me) was the descriptions of the various models that had been constructed to prove the design's concept. One of which is very close (Model J) to the four 'V.3's' I have, which I hadn't noticed before....talk about a lucky stumble in the dark by the blind...*L*
It also mentions making a version 6' tall and 6' dia. to be driven by 500 watts. Boy howdy...how about 4 of Those in your living room!
...and our respective spouses/significant others would find some horrible fate to visit upon us....Oh well, way cool garage speakers. *L*
Anyway, back on subject...
My cones are rigidly affixed top and bottom with adhesive. No fails at either end, no buzzing or mechanical noise noted by my tin ears.
The surround material is 2mm EVA foam (Darico 'Foamies', "Great for any craft project!") from Michaels, selected because it had a nice 'feel'. Doesn't compress 'twixt thumb and fingers, flexible but springs back flat, doesn't crease. Cuts easily, and available with or without adhesive on one face. I've tried both, non-adhesive version sticks well with my adhesive transfer film tape or #77 spray.
Cut into a flat ring, inner and outer diameters based on size of cone; I've been leaving a 'skirt' on the inner dia. of about .25", a space between cone and surround support inner diameter of .25" to .375" varying with the size of the cones (larger cone=larger space), and a minimum of .25" for mounting on the support structure. It's laid up essentially flat, with a slight compression to make gluing up the cone edge easier. It's a pain to have the cone shift out of center when one's trying to lay down a nice bead of glue (3M #4475; glues nearly anything to anything else, and not so unforgiving as cyanoacrylates...).
That's How, and up to now, typical.
Mags, the 'booming' I got with the 3.5 bass reduced considerably when I removed the PVC tube base from the wood base that held it all off the floor +/- 2.5". I chalked that up to 'terminating the enclosure' and eliminating the back wave coming off the interior of the cone and into the 6" pipe support. I've noticed the same effect with my other models...they 'settle down and play nice'. That back wave, if handled correctly with an appropriate sized enclosure, could provide additional bass reinforcement...which is likely what Ohm currently does, and was certainly done with the F's and A's.
The one thing I've tried since is to insert under the surround a foam ring of .625" backer rod (yep, the stuff used to fill cracks before applying caulk; I keep it around because I use it periodically, and NO, I'm NOT going to apply it to self Anywhere....that's not funny...😉 ) to try to provide additional damping under the cone's bottom edge....
It worked...somewhat... It seems to have brought out some harmonics that exhibit themselves with certain frequencies. This perhaps could be the price paid for trying damp pistonic motion brought about from the larger cone's base diameter. These motions 'hit bottom', and some reflect back up the cone to varying degrees.
Actually, I kind of expected 'something' to occur with these larger cones; it was a matter of 'what', to be followed by 'well, whatd'ya want to try' to see what happens. I'd like to find the 'magic diameter' (they ya' go, Gary *G*) where the break between wave to piston occurs. That will instruct me as to the next Version's cone size. Coupling that to mo' beefy mag/vc motors ought to be a good combination for further refinements.
Let me 'colorize' my drawing that I posted earlier, and include the backer foam to show what's where and how. A picture worth 1K words, which I've likely already surpassed....*L*
I think I should just 'lurk' more often... 😉 Y'all seem to be doing Great without my interruption...*LOL*
OK, Gary, you drove me back to the patent. I could quote chapter and verse, but it does state repeatedly that the function of the surround is to support And terminate the waveform as best as practical to eliminate reflection back up the cone. This could be performed by the surround material selection itself or multiple routines of surround structure, damping material applied to the interior of the cone, or combinations of both with various approaches as to application.
A fascinating part (for me) was the descriptions of the various models that had been constructed to prove the design's concept. One of which is very close (Model J) to the four 'V.3's' I have, which I hadn't noticed before....talk about a lucky stumble in the dark by the blind...*L*
It also mentions making a version 6' tall and 6' dia. to be driven by 500 watts. Boy howdy...how about 4 of Those in your living room!
...and our respective spouses/significant others would find some horrible fate to visit upon us....Oh well, way cool garage speakers. *L*
Anyway, back on subject...
My cones are rigidly affixed top and bottom with adhesive. No fails at either end, no buzzing or mechanical noise noted by my tin ears.
The surround material is 2mm EVA foam (Darico 'Foamies', "Great for any craft project!") from Michaels, selected because it had a nice 'feel'. Doesn't compress 'twixt thumb and fingers, flexible but springs back flat, doesn't crease. Cuts easily, and available with or without adhesive on one face. I've tried both, non-adhesive version sticks well with my adhesive transfer film tape or #77 spray.
Cut into a flat ring, inner and outer diameters based on size of cone; I've been leaving a 'skirt' on the inner dia. of about .25", a space between cone and surround support inner diameter of .25" to .375" varying with the size of the cones (larger cone=larger space), and a minimum of .25" for mounting on the support structure. It's laid up essentially flat, with a slight compression to make gluing up the cone edge easier. It's a pain to have the cone shift out of center when one's trying to lay down a nice bead of glue (3M #4475; glues nearly anything to anything else, and not so unforgiving as cyanoacrylates...).
That's How, and up to now, typical.
Mags, the 'booming' I got with the 3.5 bass reduced considerably when I removed the PVC tube base from the wood base that held it all off the floor +/- 2.5". I chalked that up to 'terminating the enclosure' and eliminating the back wave coming off the interior of the cone and into the 6" pipe support. I've noticed the same effect with my other models...they 'settle down and play nice'. That back wave, if handled correctly with an appropriate sized enclosure, could provide additional bass reinforcement...which is likely what Ohm currently does, and was certainly done with the F's and A's.
The one thing I've tried since is to insert under the surround a foam ring of .625" backer rod (yep, the stuff used to fill cracks before applying caulk; I keep it around because I use it periodically, and NO, I'm NOT going to apply it to self Anywhere....that's not funny...😉 ) to try to provide additional damping under the cone's bottom edge....
It worked...somewhat... It seems to have brought out some harmonics that exhibit themselves with certain frequencies. This perhaps could be the price paid for trying damp pistonic motion brought about from the larger cone's base diameter. These motions 'hit bottom', and some reflect back up the cone to varying degrees.
Actually, I kind of expected 'something' to occur with these larger cones; it was a matter of 'what', to be followed by 'well, whatd'ya want to try' to see what happens. I'd like to find the 'magic diameter' (they ya' go, Gary *G*) where the break between wave to piston occurs. That will instruct me as to the next Version's cone size. Coupling that to mo' beefy mag/vc motors ought to be a good combination for further refinements.
Let me 'colorize' my drawing that I posted earlier, and include the backer foam to show what's where and how. A picture worth 1K words, which I've likely already surpassed....*L*
OK, here's the Real Thang.
Bass unit drawing...for scaling purposes, the EMT supports are 11.5" tall. Actual height of the 6" dia. pipe is 12.75"....
I already see something I want to correct IRL. The backer rod should be placed directly under the bottom edge of the cone. If it's 'off center' the way it shows here, the cone is still able to move vertically. I'll just add another rod of appropo diameter to 'shim' the larger rod over. We'll see what occurs with that routine....
I'll still taken by the thought of a 6' x 6' cone...water cool the vc, make it out of 12 gauge wire, drive it with a kilowatt or three...use a small swimming pool filled with oil for a surround....the nearest 'real' neighbor is an 1/8 mi. away....I wonder how long I could play some F. Zappa before they came and dragged me away...*G*
"The bass lines were breaking windows!"
"So?"
Bass unit drawing...for scaling purposes, the EMT supports are 11.5" tall. Actual height of the 6" dia. pipe is 12.75"....
I already see something I want to correct IRL. The backer rod should be placed directly under the bottom edge of the cone. If it's 'off center' the way it shows here, the cone is still able to move vertically. I'll just add another rod of appropo diameter to 'shim' the larger rod over. We'll see what occurs with that routine....
I'll still taken by the thought of a 6' x 6' cone...water cool the vc, make it out of 12 gauge wire, drive it with a kilowatt or three...use a small swimming pool filled with oil for a surround....the nearest 'real' neighbor is an 1/8 mi. away....I wonder how long I could play some F. Zappa before they came and dragged me away...*G*
"The bass lines were breaking windows!"
"So?"
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Hi Jerry. Yeah, that's how I thought you constructed the proto. I was just focusing on whether (or not) the 2mm EVA foam surround was [constricting] the cone movement too much. Seems like vertical movement would be good, but not so in horizontal? I've never tried that method of termination.
Do still make a cone out of paper (or some other lighter material) and report back.
Oh, I was jammin on some Lee Dorsey
Do still make a cone out of paper (or some other lighter material) and report back.
Oh, I was jammin on some Lee Dorsey
Well, you want that pistonic motion, that's your bass freqs. What you are describing [sounds] like either 1/4 wave "tube" resonance, or the cone itself resonating. I made a large cone (9 in.) and at certain freqs went into "bell-mode", you could see the sine waves as they traced their way around the perimeter of the cone (no surround). It sounded like a flag flapping in the wind.
Happy Weekend, Warriors!
There's vertical movement, to be sure...I'm just playing about with levels of control to see what occurs. The glue @ the perimeter of the cone base ( a nominal 1/8" bead) locks it down to the surround, so there's no horizontal movement at all. I took care in ensuring that the cone is centered on the surround, for the sake of precision, all that...
Resonance surely could be coming into play here as well; good call. 😉 The size of the cone is such that it could be asserting itself...earlier versions are smaller, so the frequency would be higher and not so noticeable. I've really got to 'get serious', stick the mic up to them and feed some sweeps into the input. That would give me/us a better handle on what's going on.
It's just too much fun to enjoy the fact that the silly things work, y'know? *L* Warts 'n all... When an instrument appears to be Behind you, and Stays there...in a 2 channel mode, with 2 chan material...it really makes one stop and wonder Why that's happening.
Reminds me of physic's 'spooky action at a distance'', seen in sub-atomic particles...."We don't now Why, but There It Is." The deeper one digs, the more complex it gets...
I like this universe...makes your wildest dreams tame. I know we'll never get to the end of the 'story line', 'The End', last page, all that, but the current chapter has some great plot lines and a cast of billions to be entertained and/or disgusted by. Something for everyone, which is only right and fair...even if life isn't overall, which is to be expected, IMHO. Bell curves, statistical anomalies, et al....
...and I get to chat and compare notes with y'all...*G* And Bloom County is 'B-AACK!*
Life is sweet....mostly. *L*
There's vertical movement, to be sure...I'm just playing about with levels of control to see what occurs. The glue @ the perimeter of the cone base ( a nominal 1/8" bead) locks it down to the surround, so there's no horizontal movement at all. I took care in ensuring that the cone is centered on the surround, for the sake of precision, all that...
Resonance surely could be coming into play here as well; good call. 😉 The size of the cone is such that it could be asserting itself...earlier versions are smaller, so the frequency would be higher and not so noticeable. I've really got to 'get serious', stick the mic up to them and feed some sweeps into the input. That would give me/us a better handle on what's going on.
It's just too much fun to enjoy the fact that the silly things work, y'know? *L* Warts 'n all... When an instrument appears to be Behind you, and Stays there...in a 2 channel mode, with 2 chan material...it really makes one stop and wonder Why that's happening.
Reminds me of physic's 'spooky action at a distance'', seen in sub-atomic particles...."We don't now Why, but There It Is." The deeper one digs, the more complex it gets...
I like this universe...makes your wildest dreams tame. I know we'll never get to the end of the 'story line', 'The End', last page, all that, but the current chapter has some great plot lines and a cast of billions to be entertained and/or disgusted by. Something for everyone, which is only right and fair...even if life isn't overall, which is to be expected, IMHO. Bell curves, statistical anomalies, et al....
...and I get to chat and compare notes with y'all...*G* And Bloom County is 'B-AACK!*
Life is sweet....mostly. *L*
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OK, I'll give that an official
🙁 I know, it's harsh. But, the cone has at least two degrees of movement; longitudinal and tangential. It's the tangential (horizontal) that produces sound waves, also called bending waves.
So, swap out those surrounds, and I will come down there to audition them 🙂 (well, maybe one of these days) 😎
Have to to get back to my electrostatic piezo semiconductor graphene cone...
p.s. thanks for the comic clip
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Sorry if I sound crass at times, still trying to learn how to play in the sandbox. 😕
Really just trying to be of help to the greater good of all.
p.s. Buying foam surround replacements doesn't appear like a good idea after all. They are $25-30 US for two of them. Too much IMO for test protos. maybe someone can come up with a better idea?
Really just trying to be of help to the greater good of all.
p.s. Buying foam surround replacements doesn't appear like a good idea after all. They are $25-30 US for two of them. Too much IMO for test protos. maybe someone can come up with a better idea?
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Oh, be harsh. *L* It's OK, we're so into 'being mutual' and avoiding arguments, it can get a bit saccharine at times. I can throw stuff at the screen and you'd never have a clue. *L*
And since I build sandboxes, fill them, and Refill them, you'd be surprised how much sand probably gets tossed about. So, kick sand when you feel it's necessary. *G* I promise not to send anything disturbing via snail mail to retaliate. 😉
Tangential movement, agreed, is a Good Thing, yes. The amount being expressed at the lower edge is likely being damped by the EVA. I've noticed that, if I place thumb and forefinger on the cones under drive and move them vertically, it acts like a physical eq. Cute parlor trick. This is one effect that moves me to find the level on the cone where the shift from longitudinal and tangential takes place. That's where I'd like to define the height/diameter of any further cone sizes to 'damp @ the sweet spot'. I'm still more interested in turning lower bass frequencies over to something conventional, and let the cone 'sing' in the range it seem more suited to.
There is/was a complexity to the old F's and A's that bluntly I'm trying to avoid. In the sense of one can't be all things to all people, IMHO this is also true for any 'full range' speaker. You Will Give Up Something in that pursuit; the extremes at top and bottom can't be expressed without complexity or compromise. Going with a 3 way version can allow this to explored and come to some sort of conclusions about what's possible without getting too deep into the weeds, which will happen eventually anyway.
But I hope by then I'll have some 'deeper insight' as to WTF I'm up to. *L*
Yeah, foam surrounds can get pricey, and then there's find ones the right size, composition, flex/no flex, blah blah.... For now, a 2$ sheet of EVA seems to work 'good enough'. The first unit I made used a piece of the white sheet foam used to pack things in boxes, flat, didn't tear, 1/16" thick. Worked just fine until the vc cooked. *shrug*
And I appreciate your help, insights, crass comments, all that. There are no dumb questions, there's just silent stupidity. I'd rather be ranted at then left clueless in the dark. So, please, keep it up. *S*
BTB, and formally. All y'all...Thank You. If you read anything that strikes you 'sideways', sound off. All welcome, all served, none refused.
There....*G*
Also, BTB...re the comic. BB/BC 2015 will only be at his FB page. No syndication, but no editors or limits, either. 😉 The blade of irony can be quite sharp in this fashion.
...and I'm going to be posting a 'serial' of my own shortly.
...and, yeah, 'come on down' when you feel like a 'road trip' this way. If I've any excuse to head up to Chicagoland, you'd be on the itinerary. 😉
And since I build sandboxes, fill them, and Refill them, you'd be surprised how much sand probably gets tossed about. So, kick sand when you feel it's necessary. *G* I promise not to send anything disturbing via snail mail to retaliate. 😉
Tangential movement, agreed, is a Good Thing, yes. The amount being expressed at the lower edge is likely being damped by the EVA. I've noticed that, if I place thumb and forefinger on the cones under drive and move them vertically, it acts like a physical eq. Cute parlor trick. This is one effect that moves me to find the level on the cone where the shift from longitudinal and tangential takes place. That's where I'd like to define the height/diameter of any further cone sizes to 'damp @ the sweet spot'. I'm still more interested in turning lower bass frequencies over to something conventional, and let the cone 'sing' in the range it seem more suited to.
There is/was a complexity to the old F's and A's that bluntly I'm trying to avoid. In the sense of one can't be all things to all people, IMHO this is also true for any 'full range' speaker. You Will Give Up Something in that pursuit; the extremes at top and bottom can't be expressed without complexity or compromise. Going with a 3 way version can allow this to explored and come to some sort of conclusions about what's possible without getting too deep into the weeds, which will happen eventually anyway.
But I hope by then I'll have some 'deeper insight' as to WTF I'm up to. *L*
Yeah, foam surrounds can get pricey, and then there's find ones the right size, composition, flex/no flex, blah blah.... For now, a 2$ sheet of EVA seems to work 'good enough'. The first unit I made used a piece of the white sheet foam used to pack things in boxes, flat, didn't tear, 1/16" thick. Worked just fine until the vc cooked. *shrug*
And I appreciate your help, insights, crass comments, all that. There are no dumb questions, there's just silent stupidity. I'd rather be ranted at then left clueless in the dark. So, please, keep it up. *S*
BTB, and formally. All y'all...Thank You. If you read anything that strikes you 'sideways', sound off. All welcome, all served, none refused.
There....*G*
Also, BTB...re the comic. BB/BC 2015 will only be at his FB page. No syndication, but no editors or limits, either. 😉 The blade of irony can be quite sharp in this fashion.
...and I'm going to be posting a 'serial' of my own shortly.
...and, yeah, 'come on down' when you feel like a 'road trip' this way. If I've any excuse to head up to Chicagoland, you'd be on the itinerary. 😉
Thanks. And, thanks for your "quick replies", Jerry. 😉
As far as the surround thing, I always was saving that for last. There are so many different ways to skin that cat.
Actually, I always used the surround that was on the speaker that was sacrificed. That is, I jacked up the motor with struts attached to the original mounting ring and up to the magnet assembly. Then, the new cone was transplanted in place. That's probably the best case scenario for a cheap and dirty proto.
As far as the surround thing, I always was saving that for last. There are so many different ways to skin that cat.
Actually, I always used the surround that was on the speaker that was sacrificed. That is, I jacked up the motor with struts attached to the original mounting ring and up to the magnet assembly. Then, the new cone was transplanted in place. That's probably the best case scenario for a cheap and dirty proto.
