Happy to see you're merely a C19 captive like the 'smarter' souls here in the States....and I for one don't find your site all that primitive....
Esp. in the content depicted....your 3D work is terrific, carry on...��
The 1.7khz seems a snag that ought to be 'relatively easy' to turn down. *L* 'Relative' being 'relative'....
As for the 'hot' DAC, I've always been a fan of 'fans'....
"If it's got vent holes, it gets fanned." The tube crowd can't seem to grasp that....*shrug*
Cheers, J
Esp. in the content depicted....your 3D work is terrific, carry on...��
The 1.7khz seems a snag that ought to be 'relatively easy' to turn down. *L* 'Relative' being 'relative'....
As for the 'hot' DAC, I've always been a fan of 'fans'....
"If it's got vent holes, it gets fanned." The tube crowd can't seem to grasp that....*shrug*
Cheers, J
Well, that went *foom*...
Albert, all the pics and such you tried to post didn't seem to survive, save this one...
Shared album - Albert Schweitzer - Google Photos
Nice enough to trigger drilling after a link or image, but even here:
rubanoide loudspeaker - Google Search
...nothing of that sort to be seen, but enough imagery and pics to keep one drilling about for awhile..
Although I'd bet you've plowed through most already...*S*
Some of the diaphragm prep pics are compelling to me for further study; I only gave them a cursory look. But it appeared to me that most are involved
with using films rather than papers....but that's only a guess....*shrug*
Sparrowlegs (I assume that's a nickname....physical reality? 🤷*♂️🙄 Up to him to correct....*G*) has indicated that his latest is 135g paper. From what I've gathered, akin to poster stock, which may be a tad 'heavy' or has the physical mass that induces his 1.7Khz 'bump'....
Just a guess, having not 'gotten into the weeds' on rubanoides....poking at:
Audio Consulting of Switzerland Loudspeakers - Atelier 13 Audio
....site, their units have rather large membranes...
I also find it interesting their use of an AMT driver above 12Khz...so there's an upper limit to how far 'up' a large driver can reach.
I'm of a mind that same limitation is inherent in Walsh drivers; one can only expect so much from a 'one size fits all' cone....
The larger the driver, the more one depends on major excursions, which Has to effect the higher fq.; the smaller, the more the lower fq. suffers....
The devil resides in the compromises one makes.
If you both would PM me, I've an offer y'all might like.
Cheers, Jerry
Albert, all the pics and such you tried to post didn't seem to survive, save this one...
Shared album - Albert Schweitzer - Google Photos
Nice enough to trigger drilling after a link or image, but even here:
rubanoide loudspeaker - Google Search
...nothing of that sort to be seen, but enough imagery and pics to keep one drilling about for awhile..
Although I'd bet you've plowed through most already...*S*
Some of the diaphragm prep pics are compelling to me for further study; I only gave them a cursory look. But it appeared to me that most are involved
with using films rather than papers....but that's only a guess....*shrug*
Sparrowlegs (I assume that's a nickname....physical reality? 🤷*♂️🙄 Up to him to correct....*G*) has indicated that his latest is 135g paper. From what I've gathered, akin to poster stock, which may be a tad 'heavy' or has the physical mass that induces his 1.7Khz 'bump'....
Just a guess, having not 'gotten into the weeds' on rubanoides....poking at:
Audio Consulting of Switzerland Loudspeakers - Atelier 13 Audio
....site, their units have rather large membranes...
I also find it interesting their use of an AMT driver above 12Khz...so there's an upper limit to how far 'up' a large driver can reach.
I'm of a mind that same limitation is inherent in Walsh drivers; one can only expect so much from a 'one size fits all' cone....
The larger the driver, the more one depends on major excursions, which Has to effect the higher fq.; the smaller, the more the lower fq. suffers....
The devil resides in the compromises one makes.
If you both would PM me, I've an offer y'all might like.
Cheers, Jerry
HAHA. Yes, my wife has always called me Sparrowlegs due to obvious reasons.
Regarding the 1.7khz hump and the 135g paper. Not is all that it seems. Firstly the hump. After some observations, I've deduced that this was due to a combination on things, gravity, VC and the elastics. My VU is 10cm (give or take). I conducted a few near field measurements and noticed a 6db difference depending where I was measuring. For example, the higher up you measured, the lower the hump.
This is where gravity and the elastics come into play. Just to prove a point, I span the driver upside down. And the same issue occurred. So, this means that the length of the VU (38AWG) is not taut, the RF kicks in. 1.7khxz is 20cm in my book.
Also I wonder if the fact that my holes for the elastic is also on the large side in comparison. Something to investigate this weekend.
Regarding the 1.7khz hump and the 135g paper. Not is all that it seems. Firstly the hump. After some observations, I've deduced that this was due to a combination on things, gravity, VC and the elastics. My VU is 10cm (give or take). I conducted a few near field measurements and noticed a 6db difference depending where I was measuring. For example, the higher up you measured, the lower the hump.
This is where gravity and the elastics come into play. Just to prove a point, I span the driver upside down. And the same issue occurred. So, this means that the length of the VU (38AWG) is not taut, the RF kicks in. 1.7khxz is 20cm in my book.
Also I wonder if the fact that my holes for the elastic is also on the large side in comparison. Something to investigate this weekend.
*L* My spouse keeps wanting to fatten me up, but I'm quite happy to be where I is, +/- 145ish lbs. Less to 'drag about', I prefer 'nimble' over hp....
Pity you're waking up just as I'm about to inspect the backs of eyelids....
Anyway...take me up on the PM request, and leave name and email address.
I promise not to flood you with BS, other than my normal blather...:0
Cheers, and Good Morning, Britannia!
J
Pity you're waking up just as I'm about to inspect the backs of eyelids....
Anyway...take me up on the PM request, and leave name and email address.
I promise not to flood you with BS, other than my normal blather...:0
Cheers, and Good Morning, Britannia!
J
The sun is going up
Hello Rubanoid friends, thanks again for your posts.
I have now built a prototype and have been listening to it for a few days. So only 1 piece.
My centering spider, which I did not find in the forum, seems important to me. At first it was a bit too rigid, but then it was good to cut it open. With this type of spider, the voice coil can be centered and stabilized very precisely. It consists of a shrink tube and a black foam, which is used for speaker chassis.
Shared album - Albert Schweitzer - Google Photos
Shared album - Albert Schweitzer - Google Photos
The sound was good at first, but not as fantastic as described here. So don't talk about magic. But at least with high efficiency. So what did I have to improve?
I take the Manger MSW construction as a role model, since I have heard it for almost 30 years. Since he was often broken due to overload, I broke up with him.
I listen to conventional speakers for 6 months, but not with great satisfaction.
Now I come to the most important update.
First I glued the monacor MDM-20 unr on the long sides, back and front. The black peaks (triangles).
And now I have to have a big mouth.
It is hard to believe, after I had attached the Monacor MDM-20 up and down, almost half the length of the membrane, the sound became much better !!!!!!!!
In the same way as the Manger sound !!!!
So forget the paper experiments, that doesn't help, only the attenuation of reflections really makes sense!
The sound is fantastic. If you do not use damping on the outskirts, you only hear with half the quality.
If a do-it-yourself builder would like to check this, I would be very happy to get an answer here in the forum.
[url]https://photos.app.goo.gl/fzn6YQmzg3iyiDDf6
Shared album - Albert Schweitzer - Google Photos
https://photos.app.goo.gl/5w6j88XkKQciaN7h7[/URL]
Hello Rubanoid friends, thanks again for your posts.
I have now built a prototype and have been listening to it for a few days. So only 1 piece.
My centering spider, which I did not find in the forum, seems important to me. At first it was a bit too rigid, but then it was good to cut it open. With this type of spider, the voice coil can be centered and stabilized very precisely. It consists of a shrink tube and a black foam, which is used for speaker chassis.
Shared album - Albert Schweitzer - Google Photos
Shared album - Albert Schweitzer - Google Photos
The sound was good at first, but not as fantastic as described here. So don't talk about magic. But at least with high efficiency. So what did I have to improve?
I take the Manger MSW construction as a role model, since I have heard it for almost 30 years. Since he was often broken due to overload, I broke up with him.
I listen to conventional speakers for 6 months, but not with great satisfaction.
Now I come to the most important update.
First I glued the monacor MDM-20 unr on the long sides, back and front. The black peaks (triangles).
And now I have to have a big mouth.
It is hard to believe, after I had attached the Monacor MDM-20 up and down, almost half the length of the membrane, the sound became much better !!!!!!!!
In the same way as the Manger sound !!!!
So forget the paper experiments, that doesn't help, only the attenuation of reflections really makes sense!
The sound is fantastic. If you do not use damping on the outskirts, you only hear with half the quality.
If a do-it-yourself builder would like to check this, I would be very happy to get an answer here in the forum.
[url]https://photos.app.goo.gl/fzn6YQmzg3iyiDDf6
Shared album - Albert Schweitzer - Google Photos
https://photos.app.goo.gl/5w6j88XkKQciaN7h7[/URL]
Last edited:
Nothing like a 'breakthrough' to make ones' spirits rise, isn't there?
Wonderful! If you could post a vid w/sound, it'd be great to hear what you're hearing.
Anytime one makes a significant improvement on DIY'ing a project, 'all and everyones' boats rise' to borrow the phrase....
Way cool, Al. ����
A thought:
When you decide to move on and build a 2nd unit, keep the angled ends of the Monacor tape on the 'outside edges' of the diaphragms. I'm wondering IF the angled pattern of the tape may be 'breaking up' any IM distortion of the reflected waveforms on the 'phrgams.
This is an issue with the Walsh cones; when the descending waveforms 'hit' the bottom of the cone, they 'bounce back' up the cone, causing IM. This is a factor noted in the original patent, and was discussed as to how it may be dealt with.
(One was a form of 'liquid damping' which could be tad difficult to do....*L*)
BTW....My posts 4/28 @ 5:28 & 6:23 AM also applied to you...if you'd like to try 'something exotic' other than paper....
It's free...only some trust. *S*
You might try Mylar, in the meanwhile...1~2 mil thickness...black, clear....drafting film....
I think your shrink tube+foam+DS tape is a neat 'centering' trick is Brilliant. *G* And you can't beat the price....
Cheers! J
Wonderful! If you could post a vid w/sound, it'd be great to hear what you're hearing.
Anytime one makes a significant improvement on DIY'ing a project, 'all and everyones' boats rise' to borrow the phrase....
Way cool, Al. ����
A thought:
When you decide to move on and build a 2nd unit, keep the angled ends of the Monacor tape on the 'outside edges' of the diaphragms. I'm wondering IF the angled pattern of the tape may be 'breaking up' any IM distortion of the reflected waveforms on the 'phrgams.
This is an issue with the Walsh cones; when the descending waveforms 'hit' the bottom of the cone, they 'bounce back' up the cone, causing IM. This is a factor noted in the original patent, and was discussed as to how it may be dealt with.
(One was a form of 'liquid damping' which could be tad difficult to do....*L*)
BTW....My posts 4/28 @ 5:28 & 6:23 AM also applied to you...if you'd like to try 'something exotic' other than paper....
It's free...only some trust. *S*
You might try Mylar, in the meanwhile...1~2 mil thickness...black, clear....drafting film....
I think your shrink tube+foam+DS tape is a neat 'centering' trick is Brilliant. *G* And you can't beat the price....
Cheers! J
Hello Jerry
It is important to use the Monacor tape. Not over the entire membrane above and below. At first I only made it halfway and then over the entire length, horizontally. There was distortion. Now I had to laboriously remove them. It's clear on the page ends, but very important above and below. Only then does the whole sound like bending waves. Just like my manager MSW. What I want to improve is an even lighter voice coil body, for even more attack. Now there is a glass fiber fabric of 0.5mm. Then 0.3mm.
A video only makes sense if two games are the same, otherwise there will be a mix of different speakers.
If I then build two new ones, I will come back to your offer to test other materials.
Best regards
It is important to use the Monacor tape. Not over the entire membrane above and below. At first I only made it halfway and then over the entire length, horizontally. There was distortion. Now I had to laboriously remove them. It's clear on the page ends, but very important above and below. Only then does the whole sound like bending waves. Just like my manager MSW. What I want to improve is an even lighter voice coil body, for even more attack. Now there is a glass fiber fabric of 0.5mm. Then 0.3mm.
A video only makes sense if two games are the same, otherwise there will be a mix of different speakers.
If I then build two new ones, I will come back to your offer to test other materials.
Best regards
Hello Jerry
Unfortunately I don't know anything about your activities.
So you've already built rubanoid?
Have you tested the way I experiment with cushioning myself? Monacor tape?
I use varnished paper, in the last third a second layer. The membrane is more than just semicircular. The ends are bent inwards!
Now my latest findings: I have built the vertical damping a little more inside, about 6mm more. the result is more high-frequency energy (also measured), no distortion. drums have more attacks, female voices have become brighter, with significantly more details, no distortion. What do you think about? But please no theoretical information, like the choice of speakers, but tested own experiences with rubanoids.
Best regards
Theo
Unfortunately I don't know anything about your activities.
So you've already built rubanoid?
Have you tested the way I experiment with cushioning myself? Monacor tape?
I use varnished paper, in the last third a second layer. The membrane is more than just semicircular. The ends are bent inwards!
Now my latest findings: I have built the vertical damping a little more inside, about 6mm more. the result is more high-frequency energy (also measured), no distortion. drums have more attacks, female voices have become brighter, with significantly more details, no distortion. What do you think about? But please no theoretical information, like the choice of speakers, but tested own experiences with rubanoids.
Best regards
Theo
Truth be told....only fair...*S*
And greetings back to you, Theo....
Have I actually built a rubanoid? No; looked into them after purchasing a pair meant to be used as tweeters. One of the pair was defective, so I researched their basic construction, the theories, history and current forms....
Decided against following up on the urge for two main reasons:
-diy'ing the 'moving coil' drive element wasn't something I'm set up to do at this time.
-I'm already fully engaged in diy'ing Walsh omnis, with great success, thanks.
Just engaged of late of making 3 pairs with smaller HF units (also Walsh; I have my own concepts as to why to do so...)
I like dipoles...I own a pair of ESS AMT large drivers that I use as a 'benchmark driver'. My spouse prefers our pair of SMGa 'Maggies' overall, but spouses' are like that.... I like ribbon drivers for their effortless accuracy.
Monacor tape....I 'googled' that name the first time you mentioned it.
Single-faced speaker foam tape. You couldn't know that I've been using tapes of nearly any version you might mention...
Single and double faced tapes; foam, with substrates, and adhesive transfer without a 'carrier'. Using 3M VHB transfer tape to adhere the seams of my cones. The 'high tack' VHBs' are to be used carefully; once down, you're done. The is no '2nd attempt' without destroying the item. If placed wrong before assembly....the only way to remove it is to rub it off with your fingertips. And when you're done, your fingernails hurt from the stress....
If you'd prefer that I don't comment or pose any suggestions, I'll be happy not to. I do have this background of being a good 'nuts & bolts' sort of designer in the past and present, but I also can keep my fingers off the keys.
I will say that angling the outboard edges of the elements makes physical sense, as well as adding additional 'stiffness' with the added layer.
It follows that it makes the elements more 'taut' overall in the center of the arcs. That would account for the improved HF response....imho....
Best to you, and carry on.
Jerry
And greetings back to you, Theo....
Have I actually built a rubanoid? No; looked into them after purchasing a pair meant to be used as tweeters. One of the pair was defective, so I researched their basic construction, the theories, history and current forms....
Decided against following up on the urge for two main reasons:
-diy'ing the 'moving coil' drive element wasn't something I'm set up to do at this time.
-I'm already fully engaged in diy'ing Walsh omnis, with great success, thanks.
Just engaged of late of making 3 pairs with smaller HF units (also Walsh; I have my own concepts as to why to do so...)
I like dipoles...I own a pair of ESS AMT large drivers that I use as a 'benchmark driver'. My spouse prefers our pair of SMGa 'Maggies' overall, but spouses' are like that....
I like ribbon drivers for their effortless accuracy.Monacor tape....I 'googled' that name the first time you mentioned it.
Single-faced speaker foam tape. You couldn't know that I've been using tapes of nearly any version you might mention...
Single and double faced tapes; foam, with substrates, and adhesive transfer without a 'carrier'. Using 3M VHB transfer tape to adhere the seams of my cones. The 'high tack' VHBs' are to be used carefully; once down, you're done. The is no '2nd attempt' without destroying the item. If placed wrong before assembly....the only way to remove it is to rub it off with your fingertips. And when you're done, your fingernails hurt from the stress....
If you'd prefer that I don't comment or pose any suggestions, I'll be happy not to. I do have this background of being a good 'nuts & bolts' sort of designer in the past and present, but I also can keep my fingers off the keys.
I will say that angling the outboard edges of the elements makes physical sense, as well as adding additional 'stiffness' with the added layer.
It follows that it makes the elements more 'taut' overall in the center of the arcs. That would account for the improved HF response....imho....
Best to you, and carry on.
Jerry
Hello Jerry
I think your detailed comment is very good, keep it up.
I find your support valuable.
And now I have to agree with you, after a long listening I found distortions. So I removed the horizontal damping. Now the sound is not quite as appealing anymore. that's why i try to extend the vertical damping.
What do you think of a 2 k synthetic resin paint that becomes very hard as a membrane coating?
Greetings Theo
I think your detailed comment is very good, keep it up.
I find your support valuable.
And now I have to agree with you, after a long listening I found distortions. So I removed the horizontal damping. Now the sound is not quite as appealing anymore. that's why i try to extend the vertical damping.
What do you think of a 2 k synthetic resin paint that becomes very hard as a membrane coating?
Greetings Theo
Just an updata and an observations relating to the last few posts... Now I spent a few years researching radialstrahler omni-directional drivers and I have the just realised that some of my past research can be translate to a rubanoid. Specifically the form of the diaphragm is nothing more than a leaf spring.
I've modelled the standing wave on similar shapes, but never seen any of the DIY crowd do the same? Attached is a few pages from some students I was helping when doing their PHD. (All based on my work which I posted a year or so back on my sparrowlegs FB page.)
Maybe worth a look if your interested in seeing why the triangles have an effect on overall performance?
Another observation, apart from Joppe, I see no measurements nor description of how people are making their Voice Coils. I would be interested in this as I'm still using AWG38 copper in an elongated bifilar coil. There is a drawback compared with an etched vc - Weight! I guess this anything there is always a trade-off, Large BL vs a peak in the SPL.
Regarding my little build which was printed a few weeks back, I had to change the outer supports as the plastic started to warp. More experimenting this weekend.
I've modelled the standing wave on similar shapes, but never seen any of the DIY crowd do the same? Attached is a few pages from some students I was helping when doing their PHD. (All based on my work which I posted a year or so back on my sparrowlegs FB page.)
Maybe worth a look if your interested in seeing why the triangles have an effect on overall performance?
Another observation, apart from Joppe, I see no measurements nor description of how people are making their Voice Coils. I would be interested in this as I'm still using AWG38 copper in an elongated bifilar coil. There is a drawback compared with an etched vc - Weight! I guess this anything there is always a trade-off, Large BL vs a peak in the SPL.
Regarding my little build which was printed a few weeks back, I had to change the outer supports as the plastic started to warp. More experimenting this weekend.
Shared album - Albert Schweitzer - Google Photos
Shared album - Albert Schweitzer - Google Photos
Hi
is my first coil. I hope you can interpret the pictures.
The aluminum part is the winding device. I have to improve it, with a rubber pad, so that the tension in the coil is maintained. after wrapping, glue it with, for example, glass fiber plate.
my english is weak so i can't read your documents. Too bad
regards
Shared album - Albert Schweitzer - Google Photos
Hi
is my first coil. I hope you can interpret the pictures.
The aluminum part is the winding device. I have to improve it, with a rubber pad, so that the tension in the coil is maintained. after wrapping, glue it with, for example, glass fiber plate.
my english is weak so i can't read your documents. Too bad
regards
Last edited:
Theo, still mulling over 'resin or not to resin'....(maybe Google Translate?...just a thought....*s*)
Sparrow....a leaf spring in the round? "The plastic warped..." Heat? It would seem that the amount of physical bracing would inhibit that.
As for infill of the spheres...I noted that within the Walsh cone there would be radiation that ought to be 'damped out'.
My solution is an interior cone of acoustic foam...hard to diy, but worth the effort...
Infilling a rubanoid (esp. a tall version) ought to be an interesting thing to try....but just a thought to contemplate..
Sparrow....a leaf spring in the round?
"The plastic warped..." Heat? It would seem that the amount of physical bracing would inhibit that.As for infill of the spheres...I noted that within the Walsh cone there would be radiation that ought to be 'damped out'.
My solution is an interior cone of acoustic foam...hard to diy, but worth the effort...
Infilling a rubanoid (esp. a tall version) ought to be an interesting thing to try....but just a thought to contemplate..
Why did my photo disappear again? so again. My membrane shape is not a leaf spring.
what do you mean jerry
Shared album - Albert Schweitzer - Google Photos
The expansion of vertical damping is a complete success. The sound is perfect. So as you say no horizontal damping. I have to thank you, jerry!
regards
what do you mean jerry
Shared album - Albert Schweitzer - Google Photos
The expansion of vertical damping is a complete success. The sound is perfect. So as you say no horizontal damping. I have to thank you, jerry!
regards
Last edited:
Pardon, the 'leaf spring' comment was to Sparrowlegs, who made the observation about his omni-drivers.
A rubanoids' diaphragms' motion reminds me more of a segment of a tubular balloon at right angles' to it's length-wise axis.
My Walsh cones', that of a bell. with radial modes....
Simplistic, but decently accurate....*g*
I appreciate your thanks, but feel that the success is yours to enjoy. ��������
I simply try to make the odd half-bright observation.
It's your mind and hands that make the Reality happen.
Now, go make a 2nd one....and enjoy fully 'what hath you wrought'.
2 channels are Always Better than mono....*G*
Congratulations, and regards, J
A rubanoids' diaphragms' motion reminds me more of a segment of a tubular balloon at right angles' to it's length-wise axis.
My Walsh cones', that of a bell. with radial modes....
Simplistic, but decently accurate....*g*
I appreciate your thanks, but feel that the success is yours to enjoy. ��������
I simply try to make the odd half-bright observation.
It's your mind and hands that make the Reality happen.
Now, go make a 2nd one....and enjoy fully 'what hath you wrought'.
2 channels are Always Better than mono....*G*
Congratulations, and regards, J
Hello jerry
Nevertheless you can see the difference in my picture. From semicircular to expanded semicircular. you can imitate the movement with a sheet of paper. A fundamental difference. semicircular there is significant movement to the side at the end of the curve, I find it not good at all and causes disturbances.
greeting
Nevertheless you can see the difference in my picture. From semicircular to expanded semicircular. you can imitate the movement with a sheet of paper. A fundamental difference. semicircular there is significant movement to the side at the end of the curve, I find it not good at all and causes disturbances.
greeting