Hi, 6to......
I'm always suspicious of things wrapped (or can I say 'cloaked') in round metal containers, unless it's canned food. And yes, the current Ohms sound good. But....I have my prejudices, which are undoubtedly obvious by now if you've tread this thread enough..*G* Shiny metal inverted cones, please.
Hi Jerry, I'm eyeing 4 used subwoofer drivers for $15 ea. with 1.5" coils that could become donors for a "Walsh" conversion... They are rated for 200 watt max. Might be fun to experiment with and compare to my existing setup. My biggest hesitation is time available (0). I could always store them for retirement in 5 years!
maybe the technology will have become that much more accessible by then...
6to, yeah, I'd go for that...What's the diameter of the existing cones? Oh, and 'just because'...verify that they still work...sub drivers these days tend to get 'pushed' by the more 'exuberant' of us and voice coils are pretty noncommittal about being dead...
I've run into (small) boat anchors....and one can have only so many magnets...
Yeah, Reality....such as it was....*G*
Leaving Charlotte tomorrow...99.9% done, have some details that require a shop in my mitts to pull off. Looks like an 'overnight speed tour' next week, coupled with a delivery in Raleigh of the walnut slab stuff...
Seriously off-topic, but I'm too tired to show much upset over my faux paus...*L*
I've run into (small) boat anchors....and one can have only so many magnets...
Yeah, Reality....such as it was....*G*
Leaving Charlotte tomorrow...99.9% done, have some details that require a shop in my mitts to pull off. Looks like an 'overnight speed tour' next week, coupled with a delivery in Raleigh of the walnut slab stuff...
Seriously off-topic, but I'm too tired to show much upset over my faux paus...*L*
rsheptak, no...but thanks for the suggestion. I'm interested in playing about with them as a DML, using aluminum honeycomb as the panel material. I think the interaction between the sound 'field' that they create and that of the Walsh's would be perhaps novel. Would they augment or cancel? Could it be manipulated by tweaking delays between one or the other? Just the sort of thing I'm curious about.....*G*
Two other reasons, off the top of my head (such as it is)...they tend to be lower wattage (the next V.4 series of drivers I'm going to use will do 100 WRMS, 400 peak vs. the lower drive levels exhibited by the exciters (I've got my pic already bookmarked)...the other is a mechanical one, coupling the cones to the vc/magnet with adhesive. The DML's have a flat plate with an adhesive that would have to be removed so I could use the goo of my choice. My concern lies in that without a flange on the top tip of the cone, there's not much in contact. The bond would be entirely the adhesive, which would undergo significant stress in excursion. Putting a flange on the top of a cone is a ragged PIA. *L* Hard to make nice 'n flat...at 1" dia.
When I mount a cone to a modified driver, I cut the cone and leave a 'lip' that forms a 'v' shaped 'trough' around the vc. I flood that with glue and immerse the top edge into it. That's about as good as it'll get, short of custom making the vc/spider to properly merge with the cone.
In a large nutshell, that's my rationale, and I'm gonna stick to it. *G* But really, thanks for thinking about it. Always open to suggestion...post-hypnotic, obscure, all those...
Two other reasons, off the top of my head (such as it is)...they tend to be lower wattage (the next V.4 series of drivers I'm going to use will do 100 WRMS, 400 peak vs. the lower drive levels exhibited by the exciters (I've got my pic already bookmarked)...the other is a mechanical one, coupling the cones to the vc/magnet with adhesive. The DML's have a flat plate with an adhesive that would have to be removed so I could use the goo of my choice. My concern lies in that without a flange on the top tip of the cone, there's not much in contact. The bond would be entirely the adhesive, which would undergo significant stress in excursion. Putting a flange on the top of a cone is a ragged PIA. *L* Hard to make nice 'n flat...at 1" dia.
When I mount a cone to a modified driver, I cut the cone and leave a 'lip' that forms a 'v' shaped 'trough' around the vc. I flood that with glue and immerse the top edge into it. That's about as good as it'll get, short of custom making the vc/spider to properly merge with the cone.
In a large nutshell, that's my rationale, and I'm gonna stick to it. *G* But really, thanks for thinking about it. Always open to suggestion...post-hypnotic, obscure, all those...
Just to clarify, are you saying the lower wattage exciters would not allow the Walsh Cone to produce enough volume in general, or just for you?
Off topic: I also am looking to build a dml panel speaker, and not one using styrofoam! I found a source of both nomex and aluminum honeycomb here:
Applied Vehicle Technology
and you might find this patent info useful:
Patent US20030081799 - Flat panel sound radiator with enhanced audio performance - Google Patents
It concludes that panels with a core of phenolic resin coated Kraft paper honeycomb and a kevlar skin resulted in better bass, sonic fidelity, and was louder, than aluminum honeycomb core panels. This with a framed panel in a compliant surround with a single exciter on a spline.
Off topic: I also am looking to build a dml panel speaker, and not one using styrofoam! I found a source of both nomex and aluminum honeycomb here:
Applied Vehicle Technology
and you might find this patent info useful:
Patent US20030081799 - Flat panel sound radiator with enhanced audio performance - Google Patents
It concludes that panels with a core of phenolic resin coated Kraft paper honeycomb and a kevlar skin resulted in better bass, sonic fidelity, and was louder, than aluminum honeycomb core panels. This with a framed panel in a compliant surround with a single exciter on a spline.
Mmmm, potentially they could. Right now I'm just investigating making as robust a 'revised driver' as practical, 'given what I got'. The attachment concerns are just ghosts of my past, saying "Don't go there." DML's (without having one in hand, but looking hard at pics 'n such) depend upon a large contact area, likely made with a VHB-type adhesive patch. Whereas a cone has just this thin-az ring that needs to be push/pulled Hard to excite said cone properly. It's just a structural concern, primarily....
Thanks for the links....I'll go nose them about later. Out of town 'till Fr late, so no play until the wknd...
Thanks for the links....I'll go nose them about later. Out of town 'till Fr late, so no play until the wknd...
I won't say I been sayin this all along...
Siffness and low-mass are two good things with bending wave transducers.
Stiffness to maintain wave velocity (wider response) and, low-mass to raise efficiency across the spectrum.
G
Cochleus, I agree, stiffness and lightness are the key to getting a fuller range response, and leaving foam behind. I can't figure out from the patent if the kevlar is just stretched over the honeycomb and attached (using a damping acrylic adhesive) or if its impregnated with some resin. Any idea?
OKOKOKOK....*L* Beat sense into the senseless....
I'd guess that the Kevlar would be bonded to the honeycomb. One would want a monolithic panel, but since I'm bruised already y'all can educate and elucidate this mere mortal....
...and where would we source this wonderboard? Frames, drivers, and compliant surrounds is easy...IMHO....anyway...'till I'm wrong again....*L*
I'd guess that the Kevlar would be bonded to the honeycomb. One would want a monolithic panel, but since I'm bruised already y'all can educate and elucidate this mere mortal....
...and where would we source this wonderboard? Frames, drivers, and compliant surrounds is easy...IMHO....anyway...'till I'm wrong again....*L*
A bonding agent is a must, most likely epoxy.
@jerryrigged: your wrong much less frequently than you claim, my friend***
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*G* Well, I'd rather be wrong once in awhile...nobody likes 'know-it-alls', and I'm subject to face-plants just as much as the next entity in line...
You're developing this 'aerogel fixation' that's starting to concern me, friend C...forgetting what you're going to say is one of the early symptoms...been there, went through that, the therapy was ghastly, and I got a T-shirt that makes people cross the street into traffic..modern eq of sackcloth and ashes...thankfully, no bell, so I can sneak up on the unwary or simply stupid. 'Cleansing the gene pool' can be entertaining...
You know...(no, of course not...I haven't written it yet...)....it's struck me (happily, painlessly) that choice of resonant panel for a DML may entail the same visceral response that we have towards the various materials used in conventional drivers. Metal dome tweets, mids, woofs get purported to have a 'metallic sheen' or the like...paper, 'warm, resonant'...plastics tend to be considering 'in the middle', with their own 'signatures', dependant on the specific variety. The 'mix 'n match' of driver types with their attendant enclosure varieties yields the plethora of units we see today. Each has their own fans or detractors, which gets driven by taste, listening environment, budget, driving equipment, all the way down to the cables used to plug into the wall socket....
No wonder we get excited when someone likes something similar to what we do. Given the numerical possibilities, it's like winning a lottery.
At least we agree on the color of daylight....or do we?
I'd suspect the kevlar/resin panel to sound 'warm', while an alum h/c panel would be more 'brilliant'. The latter would actually appeal to me, deaf as I am to the higher freqs. All things otherwise equal, of course. It'd be an interesting exercise.
You're developing this 'aerogel fixation' that's starting to concern me, friend C...forgetting what you're going to say is one of the early symptoms...been there, went through that, the therapy was ghastly, and I got a T-shirt that makes people cross the street into traffic..modern eq of sackcloth and ashes...thankfully, no bell, so I can sneak up on the unwary or simply stupid. 'Cleansing the gene pool' can be entertaining...
You know...(no, of course not...I haven't written it yet...)....it's struck me (happily, painlessly) that choice of resonant panel for a DML may entail the same visceral response that we have towards the various materials used in conventional drivers. Metal dome tweets, mids, woofs get purported to have a 'metallic sheen' or the like...paper, 'warm, resonant'...plastics tend to be considering 'in the middle', with their own 'signatures', dependant on the specific variety. The 'mix 'n match' of driver types with their attendant enclosure varieties yields the plethora of units we see today. Each has their own fans or detractors, which gets driven by taste, listening environment, budget, driving equipment, all the way down to the cables used to plug into the wall socket....
No wonder we get excited when someone likes something similar to what we do. Given the numerical possibilities, it's like winning a lottery.
At least we agree on the color of daylight....or do we?
I'd suspect the kevlar/resin panel to sound 'warm', while an alum h/c panel would be more 'brilliant'. The latter would actually appeal to me, deaf as I am to the higher freqs. All things otherwise equal, of course. It'd be an interesting exercise.
...and besides...now that the political 'coarse race' has narrowed down, there's a simple solution to those 'splinter groups' that need to be taken out of the public's skin...
https://www.youtube.com/watch?v=RdG6gUUasVk&spfreload=10
Followed by:
https://www.youtube.com/watch?v=NXB6slJSbL4&index=2&list=PL17illmQL85w9lBUDemLzsQTFajeGCgOR
Sick? Yes. Fun? Well, perhaps. *L*
https://www.youtube.com/watch?v=RdG6gUUasVk&spfreload=10
Followed by:
https://www.youtube.com/watch?v=NXB6slJSbL4&index=2&list=PL17illmQL85w9lBUDemLzsQTFajeGCgOR
Sick? Yes. Fun? Well, perhaps. *L*
Well, Yes. Anything that will put a deposit in My Account would put a
on moi. 
I think aerogel is appealing because it creates a matrix/truss structure that would provide a but**oad of stiffness. And, it in itself doesn't add must to mass.
I like the honeycomb concept though, it would seem to put greater stiffness where one really needs it; in the low end.
Dylan had a line (I believe) about his dreams making him a potential client for a heart attack machine...sounds like daily 'civilized' life of late, but I digress...a lot...
As for 'deposits', sure thing...when the Lotto ticket I don't buy hits, the check'll be in the mail. Then we could move forward on 3D printing that c/a cone and leave the rest of the field sucking dust. It'd hinge on getting/making a printer that could create a lattice that small, but if chip tech can go to nanoscale, why not?
Major influx of $, that's why not. *L* Wonder if Elon Musk is into audio...?
"Hey, Elon! How about high end audio on Mars? Or in the next Tesla?"
Need some better 'product' for that pipe dream...
As for the vid...I'd like to know who choreographed that thing. Obviously an active imagination when it comes to mayhem. And "Free Bird" as the music?! *L*
I remember a disc jock back in S.F. that came on one night late and ranted that he was absolutely NOT going to play it, no matter how much it was requested. Screeched about how it 'was every drunk-azzed fools theme song that allowed them to stick their cars into oaks and walk away feeling superior, or smack their girlfriend who deserved someone...ANYONE...better than they thought they were...' A priceless radio moment, IMHO.
But that was S.F. AOR in it's heyday...long ago, far away...*sigh*
As for 'deposits', sure thing...when the Lotto ticket I don't buy hits, the check'll be in the mail. Then we could move forward on 3D printing that c/a cone and leave the rest of the field sucking dust. It'd hinge on getting/making a printer that could create a lattice that small, but if chip tech can go to nanoscale, why not?
Major influx of $, that's why not. *L* Wonder if Elon Musk is into audio...?
"Hey, Elon! How about high end audio on Mars? Or in the next Tesla?"
Need some better 'product' for that pipe dream...
As for the vid...I'd like to know who choreographed that thing. Obviously an active imagination when it comes to mayhem. And "Free Bird" as the music?! *L*
I remember a disc jock back in S.F. that came on one night late and ranted that he was absolutely NOT going to play it, no matter how much it was requested. Screeched about how it 'was every drunk-azzed fools theme song that allowed them to stick their cars into oaks and walk away feeling superior, or smack their girlfriend who deserved someone...ANYONE...better than they thought they were...' A priceless radio moment, IMHO.
But that was S.F. AOR in it's heyday...long ago, far away...*sigh*