As requested,
First of all I like thank everyone on this thread it's given me a lot of input.
My current version is based on a full range driver with a 50 mm voice coil.
I'm using carbon fiber in the cone. The size of the cone is 220 mm high and 150 mm diameter in the bottom end. It's roughly 0,16 mm thick. I'm using a 60g/sqm fiber and epoxy.
It plays from 80 to close to 20000 Hz.
How does sound? It's pretty decent. There are still lot to do primarily in the area of resonances...
Thomas
First of all I like thank everyone on this thread it's given me a lot of input.
My current version is based on a full range driver with a 50 mm voice coil.
I'm using carbon fiber in the cone. The size of the cone is 220 mm high and 150 mm diameter in the bottom end. It's roughly 0,16 mm thick. I'm using a 60g/sqm fiber and epoxy.
It plays from 80 to close to 20000 Hz.
How does sound? It's pretty decent. There are still lot to do primarily in the area of resonances...
Thomas
Attachments
Green...
Sanda, hey, that's Beautiful! *VBS* Your cone's +/- 25% larger than mine, and they roll off @ 100hz & 10~12khz @ the top. Probably due to the heavier/thicker aluminum (5mil) I use, as carbon fiber or titanium aren't in the budget for now....25mm voice coils as well.
Have you noticed any heat coming from the coils, BTW? High spl ought to warm them up, so beware 'enthusiasm' in that regard. But larger coils ought to allow more 'headroom' for you, so I'm totally jealous...*L*
...and the 'basic black' is sexy...
Except for the box....I'd lose the box, but I'm committed to the 'column look'....MHO, you can ignore. *L*
Sanda, hey, that's Beautiful! *VBS* Your cone's +/- 25% larger than mine, and they roll off @ 100hz & 10~12khz @ the top. Probably due to the heavier/thicker aluminum (5mil) I use, as carbon fiber or titanium aren't in the budget for now....25mm voice coils as well.
Have you noticed any heat coming from the coils, BTW? High spl ought to warm them up, so beware 'enthusiasm' in that regard. But larger coils ought to allow more 'headroom' for you, so I'm totally jealous...*L*
...and the 'basic black' is sexy...
Except for the box....I'd lose the box, but I'm committed to the 'column look'....MHO, you can ignore. *L*
Hi, thanks.
Yes, the sandbag is there to reduce vibrations that generates a lot of noice.
No, I haven't noticed any problems with heat build up in the voice coil (compressor) The coil is sound with rectangular aluminium and it is rated to handle 300w continius.
Yes, I'll drop the box. It's ugly I agree and it creates at least one problem. There is a standing wave at 425 Hz. The distance between the bottom of the Box and the voice coil is 0.4 meters. Ned to create a solution that does not involve loads of damping material.
Thomas
Yes, the sandbag is there to reduce vibrations that generates a lot of noice.
No, I haven't noticed any problems with heat build up in the voice coil (compressor) The coil is sound with rectangular aluminium and it is rated to handle 300w continius.
Yes, I'll drop the box. It's ugly I agree and it creates at least one problem. There is a standing wave at 425 Hz. The distance between the bottom of the Box and the voice coil is 0.4 meters. Ned to create a solution that does not involve loads of damping material.
Thomas
I suspect that the noise/vibration issue is due to the larger size of the voice coil and the overall strength and power that it can generate into the 'system' in general. I don't experience that with my current iteration, but they aren't rated to that level of wattage nor the strength of the cone material (aluminum). That and I still keep my 'exuberance' down due to heating up the coils.
You don't mention if the box is sealed or ported. If sealed, you might try porting or going to a transmission line design to tame that. I know that the current Ohm speakers do just that in some fashion.
I noticed that the German Physiks Walsh drivers seem to have no 'base' cabinet at all, which drove me to seal the bottom of the base of a pair of units I made. A venture into 'acoustic suspension', if you will. 'No cabinet, no standing wave' was the thought behind that. Or, at least, the standing wave is driven into a higher frequency... They're paired with a small subwoofer and seem to 'play well' in that configuration.
But that's just me 'playing around' with them. I really need to point a mic at them and run some 'sweeps' through them to see what that does to their performance.
Another thing I tried with that pair was to insert a foam core shaped into cone inside the cones, a la the Hegeman patent...
Patent US3032136 - Loudspeaker - Google Patents
You'll note the similarities to the Walsh cones, and the application of it. What intrigued me was the drawings showing a cone within the driven cone, which made the interior volume essentially nil. No volume, no standing waves? It seemed to 'tighten up' their response; but these are small cones (approx. 114 h x 75 dia. @ the base, 25 @ v.c.) driven by a 'dirt cheap' drivers...
I use them as 'monitors' in my office space, which is a small (8' h x 8' d x 16' w) room. Certainly 'loud enough' in here for 'practical purposes'. *L* The space itself likely creates 'standing waves'.
The foam cones are Styrofoam, used for artificial flower arrangements, from a local craft shop chain. They just happen to have a similar 'slope' to the Walsh and Hegeman cone configurations, a lucky happenstance.
The nice thing about building one's own speakers is that you can throw all manner of things at them, just to see what happens. One never knows what might occur...
"Creative play"....*S*
You don't mention if the box is sealed or ported. If sealed, you might try porting or going to a transmission line design to tame that. I know that the current Ohm speakers do just that in some fashion.
I noticed that the German Physiks Walsh drivers seem to have no 'base' cabinet at all, which drove me to seal the bottom of the base of a pair of units I made. A venture into 'acoustic suspension', if you will. 'No cabinet, no standing wave' was the thought behind that. Or, at least, the standing wave is driven into a higher frequency... They're paired with a small subwoofer and seem to 'play well' in that configuration.
But that's just me 'playing around' with them. I really need to point a mic at them and run some 'sweeps' through them to see what that does to their performance.
Another thing I tried with that pair was to insert a foam core shaped into cone inside the cones, a la the Hegeman patent...
Patent US3032136 - Loudspeaker - Google Patents
You'll note the similarities to the Walsh cones, and the application of it. What intrigued me was the drawings showing a cone within the driven cone, which made the interior volume essentially nil. No volume, no standing waves? It seemed to 'tighten up' their response; but these are small cones (approx. 114 h x 75 dia. @ the base, 25 @ v.c.) driven by a 'dirt cheap' drivers...
I use them as 'monitors' in my office space, which is a small (8' h x 8' d x 16' w) room. Certainly 'loud enough' in here for 'practical purposes'. *L* The space itself likely creates 'standing waves'.
The foam cones are Styrofoam, used for artificial flower arrangements, from a local craft shop chain. They just happen to have a similar 'slope' to the Walsh and Hegeman cone configurations, a lucky happenstance.
The nice thing about building one's own speakers is that you can throw all manner of things at them, just to see what happens. One never knows what might occur...
"Creative play"....*S*
BTW....I'm back. *S* Hi, y'all. *S*
After 7 wks. in FL & 2 wks. of recoup', restoration, and relative 'nice, normal chaos' it's nice to be able to take a moment and see if anyone's still 'listening'.
Anyhow...have picked up the parts and started doing some assembly on the V.4's. The CNC'd bases have been laid out and drilled, the tweets have been installed into theirs, and patterns are about to be created for the surrounds and assembly routines on the main cones. Tubing and hardware will begin to be cut after some 'fine tuning' of lengths...just to be sure, as 'stretchers' for that sort of thing are in short supply...
Have had 9 wks. to consider cone fabrication, still a major routine to get into. Rolling them is still a hands-on activity that demands time, patience, and a high degree of attention and care. I'm planning on doing a 'test crash dummy' or three to ensure I can create 4 final ones that exhibit a high degree of duplication and quality control.
Getting my head back into the quest has taken some 'goofing around' with side projects, just to 'warm up' the hands that will do the deed...
...and I'm just about There. *G*
After 7 wks. in FL & 2 wks. of recoup', restoration, and relative 'nice, normal chaos' it's nice to be able to take a moment and see if anyone's still 'listening'.
Anyhow...have picked up the parts and started doing some assembly on the V.4's. The CNC'd bases have been laid out and drilled, the tweets have been installed into theirs, and patterns are about to be created for the surrounds and assembly routines on the main cones. Tubing and hardware will begin to be cut after some 'fine tuning' of lengths...just to be sure, as 'stretchers' for that sort of thing are in short supply...
Have had 9 wks. to consider cone fabrication, still a major routine to get into. Rolling them is still a hands-on activity that demands time, patience, and a high degree of attention and care. I'm planning on doing a 'test crash dummy' or three to ensure I can create 4 final ones that exhibit a high degree of duplication and quality control.
Getting my head back into the quest has taken some 'goofing around' with side projects, just to 'warm up' the hands that will do the deed...
...and I'm just about There. *G*
Have finally arrived at a methodology of rolling cones that will solve the issues I have with 'manual forming' by hand with cranky materials. And it doesn't resort to expensive machinery or Rube Goldberg extremes. I believe it will allow me to create predictable cones that don't have the issues that have pestered me with my previous attempts....
...and it won't cost an arm/leg or any other extremities that I'm fond of...*G* Every now and then the Muse smacks you upside the head and makes you pay attention...
Have also sourced some 2 mil titanium for V.5....Yes, V.5. 4, of course. Smaller, but Ti has intrigued me for some time and the opportunity arrived to give it a go.
BTW, I can get more of that material...12" wide, CP grade 2. Enough for whatever floats your boat, but I'd like some assistance with the purchase since it's more than I can conceive of using at this juncture. But if I can get a few equally 'driven' individuals interested in a 'bulk buy'...and it's not as expensive as one might think. PM if curiosity overcomes you. *G*
...and it won't cost an arm/leg or any other extremities that I'm fond of...*G* Every now and then the Muse smacks you upside the head and makes you pay attention...
Have also sourced some 2 mil titanium for V.5....Yes, V.5. 4, of course. Smaller, but Ti has intrigued me for some time and the opportunity arrived to give it a go.
BTW, I can get more of that material...12" wide, CP grade 2. Enough for whatever floats your boat, but I'd like some assistance with the purchase since it's more than I can conceive of using at this juncture. But if I can get a few equally 'driven' individuals interested in a 'bulk buy'...and it's not as expensive as one might think. PM if curiosity overcomes you. *G*
Following with interest...
Hi Jerry, I am not posting much lately, but wanted to let you know I still follow the forum regularly. I was researching AltecLansing vintage speakers, since there is a set for sale locally. I learned that the dual-or triple cone Walshes were not the only ones to use multiple materials to make a full(er)range cone... the Altec-Biflex speaker appears to have achieved this in a more traditional directional configuration: Altec BIFLEX(R) Loudspeakers Maybe something to consider for version V-101-z?
Anyhow, I'm in no position to build anything yet, since I'm in the middle of a whole-house remodel, but have been gathering tools and picking up bargains and discards, so when I do get a chance to play, I have some raw materials to experiment with. Keep up the good work!
Six - Minneapolis.
Hi Jerry, I am not posting much lately, but wanted to let you know I still follow the forum regularly. I was researching AltecLansing vintage speakers, since there is a set for sale locally. I learned that the dual-or triple cone Walshes were not the only ones to use multiple materials to make a full(er)range cone... the Altec-Biflex speaker appears to have achieved this in a more traditional directional configuration: Altec BIFLEX(R) Loudspeakers Maybe something to consider for version V-101-z?
Anyhow, I'm in no position to build anything yet, since I'm in the middle of a whole-house remodel, but have been gathering tools and picking up bargains and discards, so when I do get a chance to play, I have some raw materials to experiment with. Keep up the good work!
Six - Minneapolis.
Sixto, hi, long time no read...*G*
I understand how 'real world stuff' can interfere with the 'fun' pursuits...one gets so many 'balls in the air', it seems the only thing to do is to toss them higher and hope they don't drop faster than ascend...
Thanks for posting the AL literature, but it looks like (to me) that the cones are still composed of a single material...I suspect perhaps two different thicknesses of paper, linked with an interior ring of the same ridged like the main surround. The inner 'hf' cone could be thinner....but I wonder how it effected the 'energy transfer' to the outer cone through that inner 'surround'...
Now, This is a loudspeaker I'd love to point a calibrated mic at...
That inner surround is acting like a 'mechanical crossover', or needs to so's to function properly. If the designer(s) were able to create some 'practical magic' and not have a big 'dip' in the response in the overall unit, I would be major impressed.
One might or maybe able to compensate for anything at that range with the cabinet design, making the resonant frequency 'just so' to smooth it out, but it'd be a crap shoot. Any 'raw driver' sold to the public is subject to all sorts of 'interpretations......I stand as a testament to that, although the designer(s) couldn't have even dreamed of someone cutting their babies apart the way I do....*L*
But, thanks....and thanks for coming by when you can...*S*
I understand how 'real world stuff' can interfere with the 'fun' pursuits...one gets so many 'balls in the air', it seems the only thing to do is to toss them higher and hope they don't drop faster than ascend...
Thanks for posting the AL literature, but it looks like (to me) that the cones are still composed of a single material...I suspect perhaps two different thicknesses of paper, linked with an interior ring of the same ridged like the main surround. The inner 'hf' cone could be thinner....but I wonder how it effected the 'energy transfer' to the outer cone through that inner 'surround'...
Now, This is a loudspeaker I'd love to point a calibrated mic at...
That inner surround is acting like a 'mechanical crossover', or needs to so's to function properly. If the designer(s) were able to create some 'practical magic' and not have a big 'dip' in the response in the overall unit, I would be major impressed.
One might or maybe able to compensate for anything at that range with the cabinet design, making the resonant frequency 'just so' to smooth it out, but it'd be a crap shoot. Any 'raw driver' sold to the public is subject to all sorts of 'interpretations......I stand as a testament to that, although the designer(s) couldn't have even dreamed of someone cutting their babies apart the way I do....*L*
But, thanks....and thanks for coming by when you can...*S*
Merry Pre-Xmas & HNY '18 -Jumping the Calendar (Safer than the shark...)>
Hi to any and all watching....*G*
Still 'out here'....been preoccupied with RL work and personal medical issues that needn't be gone into....(*L* Book and movie rights available cheap...)
Spouse claims I've too many speakers around (...but allowed me to score a pair of nearly mint Maggies'....go figure....*G*) so I'm working toward 'thinning my flock'...
...and (of course) replacing them with the next versions (Yes, plural..), thereby starting the whole cycle again...
...which, of course, is subject to my RL work (...one of which takes 'us' to TX in 3/'18 for +/- 1 month, another pending in KY that's....BIG....*G*)
(Attached is a RL job that's about to 'wrap' near Chapel Hill, NC. That's a fish play structure, awaiting it's metal pipe 'fins'...currently being powder coated...36' long, 45' with it's tail...206 CNC 'rib segments....)
So...Stand By for 2018. I've got....Plans....
Hi to any and all watching....*G*
Still 'out here'....been preoccupied with RL work and personal medical issues that needn't be gone into....(*L* Book and movie rights available cheap...)
Spouse claims I've too many speakers around (...but allowed me to score a pair of nearly mint Maggies'....go figure....*G*) so I'm working toward 'thinning my flock'...
...and (of course) replacing them with the next versions (Yes, plural..), thereby starting the whole cycle again...
...which, of course, is subject to my RL work (...one of which takes 'us' to TX in 3/'18 for +/- 1 month, another pending in KY that's....BIG....*G*)
(Attached is a RL job that's about to 'wrap' near Chapel Hill, NC. That's a fish play structure, awaiting it's metal pipe 'fins'...currently being powder coated...36' long, 45' with it's tail...206 CNC 'rib segments....)
So...Stand By for 2018. I've got....Plans....
Attachments
...well, Yeah....But...
*G* Actually, that space is the back 1/2 of our "office(s)/showroom/"outboard" living space" (my 'audio playspace' shares with a sauna, an exercise 'device' (hers), & misc. storage; the real shop space is in the bldg. next door, where we create 'fish parts' and the like...).
It's been suggested that the fish needs a hook. If we could figure out some way of making it safe enough for a completely unsupervised site so kids (or the random and typically inebriated adult) wouldn't permanently damage themselves on it...and develop a 'sky hook' to suspend it from....mmm, Sure. But lawyers and judges have no sense of humor about these things.
In Europe they have a much more 'liberal' view of that sort of 'play item', on the order of "If you hurt yourself or others on something that looks like you could do such, well...you should have recognized that and you're an idiot for hurting self/others." That, and the type of 'socialized' (sic) medical system that'll patch you up after acting the fool.
We've had to 'educate' designers/landscape architects/interested parties occasionally over the differences in our 'social structures' with regard to 'play equipment' ("No, we can't and won't make or install things like that. We'd rather not nor expose you to the 'legal ramifications' of what constitutes 'safe play equipment' in our country..."
We're a 'litigious society'..."I'm an idiot...I/my child hurt themselves on 'your Thing', despite the sign that told me to 1) supervise my child or self, 2) take clothing items off that may pose a hazard (children die each year from the drawstrings in their hoodies getting caught and literally hanging themselves...not a pleasant childhood memory for the ones nearby), 3) play items in the sun can get Hot, esp. slides (the plastic ones in summer sun can yield 1st degree burns....the metal ones that we grew up with (that are rarely made anymore....seen one lately? ) are Worse...
We have our 'rules and regs' to follow. We like what we do. We want your children to enjoy themselves, challenge their motor skills and strength, get some exercise Outdoors away from the Xbox and PS(#?). We want to make an Honest buck making Something that makes people and their kids Smile & laugh. *S*
...and Y'know...I can't think of Anything Else that I can do, with my skills, knowledge, experience, and talents...that I'd rather do. *S*
(*smirk*....except DIY'ing speakers...but that's Another Side of This Life I've Been Leading*.........)
*=Fred Neil, J. Airplane cover...yeah, I know....*g*....
*G* Actually, that space is the back 1/2 of our "office(s)/showroom/"outboard" living space" (my 'audio playspace' shares with a sauna, an exercise 'device' (hers), & misc. storage; the real shop space is in the bldg. next door, where we create 'fish parts' and the like...).
It's been suggested that the fish needs a hook. If we could figure out some way of making it safe enough for a completely unsupervised site so kids (or the random and typically inebriated adult) wouldn't permanently damage themselves on it...and develop a 'sky hook' to suspend it from....mmm, Sure.
But lawyers and judges have no sense of humor about these things.In Europe they have a much more 'liberal' view of that sort of 'play item', on the order of "If you hurt yourself or others on something that looks like you could do such, well...you should have recognized that and you're an idiot for hurting self/others." That, and the type of 'socialized' (sic) medical system that'll patch you up after acting the fool.
We've had to 'educate' designers/landscape architects/interested parties occasionally over the differences in our 'social structures' with regard to 'play equipment' ("No, we can't and won't make or install things like that. We'd rather not nor expose you to the 'legal ramifications' of what constitutes 'safe play equipment' in our country..."
We're a 'litigious society'..."I'm an idiot...I/my child hurt themselves on 'your Thing', despite the sign that told me to 1) supervise my child or self, 2) take clothing items off that may pose a hazard (children die each year from the drawstrings in their hoodies getting caught and literally hanging themselves...not a pleasant childhood memory for the ones nearby), 3) play items in the sun can get Hot, esp. slides (the plastic ones in summer sun can yield 1st degree burns....the metal ones that we grew up with (that are rarely made anymore....seen one lately? ) are Worse...
We have our 'rules and regs' to follow. We like what we do. We want your children to enjoy themselves, challenge their motor skills and strength, get some exercise Outdoors away from the Xbox and PS(#?). We want to make an Honest buck making Something that makes people and their kids Smile & laugh. *S*
...and Y'know...I can't think of Anything Else that I can do, with my skills, knowledge, experience, and talents...that I'd rather do. *S*
(*smirk*....except DIY'ing speakers...but that's Another Side of This Life I've Been Leading*.....
....)*=Fred Neil, J. Airplane cover...yeah, I know....*g*....
Progress:Myth,Method,Mixed Message,orMess?
*wry S*....Well, I'm not a 'role model' with regards to Progress, either....and '17 has been....
....an 'atypical sort of year'...(...personally, for sure....*g*...)
To borrow and paraphrase a line from an obscure song, while we end one orbit and begin the next:
"It may not be better, but I'll settle for Different."
Merry Post-Xmas & Happy Pre-New Year...*L* ^5's
*wry S*....Well, I'm not a 'role model' with regards to Progress, either....and '17 has been....
....an 'atypical sort of year'...(...personally, for sure....*g*...)
To borrow and paraphrase a line from an obscure song, while we end one orbit and begin the next:
"It may not be better, but I'll settle for Different."
Merry Post-Xmas & Happy Pre-New Year...*L* ^5's