As far as the measurements of this driver, here you have those that were made on the commercial version (the Airfoil) by J. Atkinson for Stereophile. Impact Airfoil 5.2 loudspeaker system Measurements | Stereophile.com. The last sentence of this page is interesting...
Hello dear colleagues,
Did anyone did some extended measurements and testing on this speaker ?
Improvements?
I want to make myself a pair of these speakers, (Rubanoide, Janus 50) and i need more info please.
I found some good neodymium magnets to play with on the internet (link bellow) :
Magnet neodim bloc, 40x10x10 mm, putere 15 kg Magnet neodim bloc mare [HQ-40-10-10-N] - 16,50RON : HOBBER!, Magnet neodim (Neodymium), ferita, benzi si foi magnetice
What do you say about these? They lift 15kg..
For the paper i was thinking about 30g/mp normal paper ( i am planing to spray it with a very thin layer of motor oil for humidity resistance, AFTER the glue has hardened and everything is in place) but dont how this thin paper resonates at mid frecvencies.
Did anyone experimented paper bellow 200g/mp? Please share some thoughts..
I am allready making some savings for the products needed for this project.
Thanks in advance
Sergiu
AAAAAAAAAAhhhh shiiiiitttt , i have to make one 
.
ok ordered magnets. neo's N42, But not the 40x20x10 but 40x20x05, i think thats plenty of power and danger. at least for me.
and its just a test version of this concept, to see if it yields any benefits compared to my esls. cost wise and size wise. ok 10 of these tiny magnets set me 32 euro back , but if i ever need allot there is this awesome cheap shop in italy , id did not order myself yet. biut on the facebook page of la folia they did. the magnets are damn cheap and they got some verry nice sizes. not N42 but hell still strong compared to feriet.
http://www.magneticshop.it/categori...manenti-neodimio/magneti-neodimio-blocchetti/
So far i tried to make the pancake coil to sandwich in between the 2 paper roles, tried 4 and all came out awfull. so im making a bobine, not sure if that works yet.
here is the design of the bobine in sketchup. im gone 3d cnc it out of HDPE since super glue does not like to stick to it. i could not find a bigger block to cut it out (only leftover i had)
https://youtu.be/mWqa6Hu7O48
i make 2 halves and because of the bevel its easier to get the wire into the 0.2mm slot.
The 2 halves are spaced with 2 pieces of nomex paper, also video on cutting that. its pretty hard somehow my knife does not like to cut nomex, it needs allot of force, out of the 6 pieces i could only use 3 the others are not cut trough and trough , and this nomex is even hard to tear. damn nasty stuff. so i could not get the holes punched out its to strong.
https://youtu.be/vtPPk_XDrGw
By the way, self bonding magnet wire would be awesome for this purpose!! wind it on bobine trow into oven , wait and get it out, and you should have a nice self supporting coil
(ofc i then need to make a bobine out of aluminium or my misses will be angry!)
.ok ordered magnets. neo's N42, But not the 40x20x10 but 40x20x05, i think thats plenty of power and danger. at least for me.
and its just a test version of this concept, to see if it yields any benefits compared to my esls. cost wise and size wise. ok 10 of these tiny magnets set me 32 euro back
, but if i ever need allot there is this awesome cheap shop in italy , id did not order myself yet. biut on the facebook page of la folia they did. the magnets are damn cheap and they got some verry nice sizes. not N42 but hell still strong compared to feriet.http://www.magneticshop.it/categori...manenti-neodimio/magneti-neodimio-blocchetti/
So far i tried to make the pancake coil to sandwich in between the 2 paper roles, tried 4 and all came out awfull. so im making a bobine, not sure if that works yet.
here is the design of the bobine in sketchup. im gone 3d cnc it out of HDPE since super glue does not like to stick to it. i could not find a bigger block to cut it out
(only leftover i had)https://youtu.be/mWqa6Hu7O48
i make 2 halves and because of the bevel its easier to get the wire into the 0.2mm slot.
The 2 halves are spaced with 2 pieces of nomex paper, also video on cutting that. its pretty hard somehow my knife does not like to cut nomex, it needs allot of force, out of the 6 pieces i could only use 3 the others are not cut trough and trough , and this nomex is even hard to tear. damn nasty stuff. so i could not get the holes punched out its to strong.
https://youtu.be/vtPPk_XDrGw
By the way, self bonding magnet wire would be awesome for this purpose!! wind it on bobine trow into oven , wait and get it out, and you should have a nice self supporting coil
(ofc i then need to make a bobine out of aluminium or my misses will be angry!)
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well this is harder then i thought. its not easy to wind a flat coil. it either does stick to the bobine. or even worse it does get nice and tight and the ends of the bobine since there is where the bobine is under the most tension when grabbing the next amount of wire, since its not a round bobine. the part in the midle is not as compact and tends to bulge so it becomes more of a O with eating disorder instead of an I
. next thinh i try is drilling some holes in one of the bobines, at places where the wire will be on the inside. now i try to wind the bobine without glue that can be in the way of winding tight. then when im done i use a seringe to push some 3M 30nf glue in let it soak around all the wires. then drop it in a oven to cure faster. and i should be able to disassemble the bobine and have a glued coil.... well thats theory
aaaauw that thing is hot..... my over cant go lower then 100c.... 30 under melting temp of HDPE, i let it coolo down before i open it. im so curious. it wont be perfect but i hope better then al my previous attempts
. next thinh i try is drilling some holes in one of the bobines, at places where the wire will be on the inside. now i try to wind the bobine without glue that can be in the way of winding tight. then when im done i use a seringe to push some 3M 30nf glue in let it soak around all the wires. then drop it in a oven to cure faster. and i should be able to disassemble the bobine and have a glued coil.... well thats theory
aaaauw that thing is hot..... my over cant go lower then 100c.... 30 under melting temp of HDPE
, i let it coolo down before i open it. im so curious. it wont be perfect but i hope better then al my previous attempts
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excuse me for all the spelling mistakes, or rather type mistakes. i cant hardly read it myself
i tend to type fast when im excited, the result is a post, that even i cant read.
Heres a picture of the best i made, nr 3 is with the seringe method.
there where others that looked more like an O so they are gone.
i tend to type fast when im excited, the result is a post, that even i cant read.
Heres a picture of the best i made, nr 3 is with the seringe method.
there where others that looked more like an O so they are gone.
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Hi Wrine,
I just finished reading a french forum where allot of giys finished these special speakers...
With those magnets i think you should get near 92-93dB.
Some ideas from that forum:
- the membrane moves 4mm at max;
-the string from the bottom and top helps the membrane so that it will not resonate and keps the coil in the gap;
-the coil should be as flat as possible, and as light as possible;
-the metal sheets are A37 steel (used by the guys from France)--this is what i whant to figure out (the type of steel needed..);
-you have to put a dampening material like rubber on the laterall sydes (where you bolt the membrane with bars and screws);
-the membrane does all the trick here... It has to be stiff, humidity resistant and have high permeability;
- with normal paper of 50-70g/square meter you would get really hifi sound BUT if the volume is too high, the membrane resonates between 200-1500hz and you would need to cut those frecvencies down or else you would get that "paper sound" (the resonances of the membrane that everybody is talking about..)
- we have to find a solution for these nasty resonances.. If this prob is solved we should have a beutifull broad band speaker, with lower power needs than a pair of Magnepans, better dispersion and higher SPL..
-allot of people sugested 70g/sqm rice paper but nobody tested it..
Cheers
Sergiu
I just finished reading a french forum where allot of giys finished these special speakers...
With those magnets i think you should get near 92-93dB.
Some ideas from that forum:
- the membrane moves 4mm at max;
-the string from the bottom and top helps the membrane so that it will not resonate and keps the coil in the gap;
-the coil should be as flat as possible, and as light as possible;
-the metal sheets are A37 steel (used by the guys from France)--this is what i whant to figure out (the type of steel needed..);
-you have to put a dampening material like rubber on the laterall sydes (where you bolt the membrane with bars and screws);
-the membrane does all the trick here... It has to be stiff, humidity resistant and have high permeability;
- with normal paper of 50-70g/square meter you would get really hifi sound BUT if the volume is too high, the membrane resonates between 200-1500hz and you would need to cut those frecvencies down or else you would get that "paper sound" (the resonances of the membrane that everybody is talking about..)
- we have to find a solution for these nasty resonances.. If this prob is solved we should have a beutifull broad band speaker, with lower power needs than a pair of Magnepans, better dispersion and higher SPL..
-allot of people sugested 70g/sqm rice paper but nobody tested it..
Cheers
Sergiu
excuse me for all the spelling mistakes, or rather type mistakes. i cant hardly read it myself
i tend to type fast when im excited, the result is a post, that even i cant read.
Heres a picture of the best i made, nr 3 is with the seringe method.
there where others that looked more like an O so they are gone.
Nr 3 is better. What glue do you intend to use for sticking it to te membranes? It has to be abit elastic but not much because the winding will not transmit the vinrations to the membrane..
excuse me for all the spelling mistakes, or rather type mistakes. i cant hardly read it myself
i tend to type fast when im excited, the result is a post, that even i cant read.
Heres a picture of the best i made, nr 3 is with the seringe method.
there where others that looked more like an O so they are gone.
yeah i was wondering about the glue as well. i tried 2 kinds to see hat even sticks to nomex (water resistant, strong, can hold its own weight, but weight im not sure yet will try to weigh), since i will be using that as material. i used super glue and Polyuethane both sticks , super glue has a bit less dampening compares to the Urethene. tomorow im free from work and will trow one together Thx sergiu for all the input.. one not on the steel, we really dont need any special steel. at least not with my build i never get to the 1.2 tesla, in the gap is now 0.7. and im not filling up the entire steel part so its going to be even less ,
5 mm gap wich is rather big still.
Thx sergiu for all the input.. one not on the steel, we really dont need any special steel. at least not with my build i never get to the 1.2 tesla, in the gap is now 0.7. and im not filling up the entire steel part so its going to be even less , 5 mm gap wich is rather big still.
The original design "Janus 50" had 1.42 Tesla in 4mm gap and 10 mm plates with 40*20*10 N45 NdBor magnets in an underhung design.
The magnets that i want to buy are 40*10*10 n42 and i think they are weak..
I think you should wound a thinner wire, and use some thicker plates for the magnets (8-6 mm) to improve the magnetic flux.
Also a smaller gap (3mm) would also help. You can make a more like cilindrical design for the membrane for a smaller gap, so that the membrane should stay in the center of the gap.
I have the money for the magnets. I need to collect more money for different flavors of paper..
I cant wait to hear some impressions from you.
Cheers
Sergiu
The magnets that i want to buy are 40*10*10 n42 and i think they are weak..
I think you should wound a thinner wire, and use some thicker plates for the magnets (8-6 mm) to improve the magnetic flux.
Also a smaller gap (3mm) would also help. You can make a more like cilindrical design for the membrane for a smaller gap, so that the membrane should stay in the center of the gap.
I have the money for the magnets. I need to collect more money for different flavors of paper..
I cant wait to hear some impressions from you.
Cheers
Sergiu
yeah i was wondering about the glue as well. i tried 2 kinds to see hat even sticks to nomex (water resistant, strong, can hold its own weight, but weight im not sure yet will try to weigh), since i will be using that as material. i used super glue and Polyuethane both sticks , super glue has a bit less dampening compares to the Urethene. tomorow im free from work and will trow one together
5 mm gap wich is rather big still.
I use 40-10-5 magnets but 1,4 tesla is insane . For me at least, I used femm to see how strong the magnet flux was, I'm happy with 92 dB or less since the bass is ob wich result in the lower 88 dB. I only see a huge problem in my steel being 3 the length my magnets are , I might need to cut things. Down or the power of the magnets might go to waste in the extensive use of steel. Or I need more magnets that don't contribute to the field strength . At least if you chose ur Steel wisely
I am Gina order some 0.13 mm alu wire wich is self bonding , and since it's alu it almost 3 times as light without giving on much to power handling
I am Gina order some 0.13 mm alu wire wich is self bonding , and since it's alu it almost 3 times as light without giving on much to power handling
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Now, after i read the french topic i'm thinking of how to reduce the "paper sound" without compromising the weight of the membrane.
In your case you could try a 45-50g/sqm paper but be carefull at the elastic string used for centering the membrane in the gap because it could cut the paper. I was thinking of stiffening the membrane with glue where you perforate the membrane for the string.
In the earlier posts on this tread a colleague of ours realised this speaker with normal magnets (3.5kg strenght) and obtained about 86dB. Your magnets have about 8kg force. You should obtain with a small gap, low membrane weight, between 90-92dB at max.
I'm curious to hear about your results.
Cheers
Sergiu
In your case you could try a 45-50g/sqm paper but be carefull at the elastic string used for centering the membrane in the gap because it could cut the paper. I was thinking of stiffening the membrane with glue where you perforate the membrane for the string.
In the earlier posts on this tread a colleague of ours realised this speaker with normal magnets (3.5kg strenght) and obtained about 86dB. Your magnets have about 8kg force. You should obtain with a small gap, low membrane weight, between 90-92dB at max.
I'm curious to hear about your results.
Cheers
Sergiu
https://m.youtube.com/watch?v=M-q2DPLMWdg
There you go à rubenoid. Points i should fix are.
- my coil had a dc resistance of 6,6 wich is About 8 ohm ac (with some lowwer an higher) i need to make a new one that Ends up around 4 ohms.
- efficiency is not high at alle i guess stond 85 or so. This is THE result in me using 180 mm bar steel and only 2 x 40x20x 05 magnets for each side. I must find a way to reduce the steel to around 100 mm , this way the field strength will be much higher. Since my coil is around 80 mm on the long usable side I opted to use only to magnets. This should be equally strong , but since the steel vs magnet ratio is out of wack I create a large 180mm long magnet gap wich is lower in strength and only 80 mm is used by the coil.
- some resonances should be dealt with. I'll post measurements tomorrow, but I must address the fact that normal conditions are out of the window, it act like an omni, but close vs far field increases high freq instead of the normall oposite.
The dispersion is insane ! It sound the same almost everywhere in the room see video. Tomorrow another day
There you go à rubenoid. Points i should fix are.
- my coil had a dc resistance of 6,6 wich is About 8 ohm ac (with some lowwer an higher) i need to make a new one that Ends up around 4 ohms.
- efficiency is not high at alle i guess stond 85 or so. This is THE result in me using 180 mm bar steel and only 2 x 40x20x 05 magnets for each side. I must find a way to reduce the steel to around 100 mm , this way the field strength will be much higher. Since my coil is around 80 mm on the long usable side I opted to use only to magnets. This should be equally strong , but since the steel vs magnet ratio is out of wack I create a large 180mm long magnet gap wich is lower in strength and only 80 mm is used by the coil.
- some resonances should be dealt with. I'll post measurements tomorrow, but I must address the fact that normal conditions are out of the window, it act like an omni, but close vs far field increases high freq instead of the normall oposite.
The dispersion is insane ! It sound the same almost everywhere in the room see video. Tomorrow another day
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Congrats Wrine,
Im sure that the rubanoid that you made has way better dispersion than the Quad stats that you have there.
I want to ask you to add two wood V shape (30 degree angle) like in the image bellow on the laterall of the ruban and then remeasure how much SPL do you have and how does it sound now.
The ruban from the image is not mine, its just for better understanding this topology..
Im sure that the rubanoid that you made has way better dispersion than the Quad stats that you have there.
I want to ask you to add two wood V shape (30 degree angle) like in the image bellow on the laterall of the ruban and then remeasure how much SPL do you have and how does it sound now.
The ruban from the image is not mine, its just for better understanding this topology..
An externally hosted image should be here but it was not working when we last tested it.
https://m.youtube.com/watch?v=M-q2DPLMWdg
There you go à rubenoid. Points i should fix are.
- my coil had a dc resistance of 6,6 wich is About 8 ohm ac (with some lowwer an higher) i need to make a new one that Ends up around 4 ohms.
- efficiency is not high at alle i guess stond 85 or so. This is THE result in me using 180 mm bar steel and only 2 x 40x20x 05 magnets for each side. I must find a way to reduce the steel to around 100 mm , this way the field strength will be much higher. Since my coil is around 80 mm on the long usable side I opted to use only to magnets. This should be equally strong , but since the steel vs magnet ratio is out of wack I create a large 180mm long magnet gap wich is lower in strength and only 80 mm is used by the coil.
- some resonances should be dealt with. I'll post measurements tomorrow, but I must address the fact that normal conditions are out of the window, it act like an omni, but close vs far field increases high freq instead of the normall oposite.
The dispersion is insane ! It sound the same almost everywhere in the room see video. Tomorrow another day
I was looking on the video and didn't notice the elastic ropes used to center the membrane, to limit the Xmax and some of the nasty resonances. Look in the picture bellow. The membrane is made out of Holphastan and has one elastic rope above and one bellow on both sides to limit the Xmax at precisely 4mm front and back. (that's a secret ) The membrane shouldn't move more than that at 200-300Hz at max out.
http://vincent.brient.free.fr/fichiers/ruban.jpg
This is what i'm trying to figure out. Those resonances that we perceive as "paper sound". These resonances appear between 200 and 1500 Hz. This is the major fault of this topology. If you cut the 200-1500hz frecquencies with a first order filter they will dissapear but this will spoil the beauty of this design...
First of all you should add the elastic ropes. Then please try to increase surface of the membrane. This is what i had in mind to further limit the "paper sound". You should obtain two big cilinders like 00 shape instead of two round OO ones like you have now.
My thinking is like that because of the low weight/sqm paper used and the membrane is heavily "loaded" and "saturates" and resonates.
I think that if we increase the surface we will use de paper dampening given by the bigger area created by the membrane paper.
Please try this ideea and tell us your results.
Congrats again
Sergiu
) The membrane shouldn't move more than that at 200-300Hz at max out. http://vincent.brient.free.fr/fichiers/ruban.jpg
This is what i'm trying to figure out. Those resonances that we perceive as "paper sound". These resonances appear between 200 and 1500 Hz. This is the major fault of this topology. If you cut the 200-1500hz frecquencies with a first order filter they will dissapear but this will spoil the beauty of this design...
First of all you should add the elastic ropes. Then please try to increase surface of the membrane. This is what i had in mind to further limit the "paper sound". You should obtain two big cilinders like 00 shape instead of two round OO ones like you have now.
My thinking is like that because of the low weight/sqm paper used and the membrane is heavily "loaded" and "saturates" and resonates.
I think that if we increase the surface we will use de paper dampening given by the bigger area created by the membrane paper.
Please try this ideea and tell us your results.
Congrats again
Sergiu
Cool !
I'm in the process of building my own Rubanoides, essentially Janus 70's, so I'm glad to see others interested in them as well. I am curious about the reference to 45-50g/m*m membranes however. The designer, M. Deminiere, clearly calls for at least 180g paper for the membranes, precisely because of the resonance issue.
I have heard for myself on several occasions how fantastic sounding the Quads are. But the Rubanoides, at least in commercial versions like the AudioNec stuff, have gotten best of show votes at a number of major audio shows. One reviewer even referred to them as being on a par with the best electorstats he had heard, but with even more dynamics and fleshed out tone. Reviews should be taken with a grain of salt naturally, but the possibility of achieving really superior performance is rather intriguing, especially if you can DIY it. Of course, not having to spend multiple thousands of Euros is nice too !!
I'm in the process of building my own Rubanoides, essentially Janus 70's, so I'm glad to see others interested in them as well. I am curious about the reference to 45-50g/m*m membranes however. The designer, M. Deminiere, clearly calls for at least 180g paper for the membranes, precisely because of the resonance issue.
I have heard for myself on several occasions how fantastic sounding the Quads are. But the Rubanoides, at least in commercial versions like the AudioNec stuff, have gotten best of show votes at a number of major audio shows. One reviewer even referred to them as being on a par with the best electorstats he had heard, but with even more dynamics and fleshed out tone. Reviews should be taken with a grain of salt naturally, but the possibility of achieving really superior performance is rather intriguing, especially if you can DIY it. Of course, not having to spend multiple thousands of Euros is nice too !!
Please excuse me, i'm tired. The V shape in laterall influnce the directivity of sound and not the Spl.
You shoul make the Janus 50 to really compare these speakers.
You shoul make the Janus 50 to really compare these speakers.
Hi Ppap,
Glad to hear that others are interested too. What type of steel do you want to use for the 10mm plates that forms the magnetic field? Steel 413?
Yesterday i bought 50g/m*m an its very very thin. Now i wonder how to centrate the membrane with the elastic ropes. As an ideea the news paper has 35-40g/sqm...
Glad to hear that others are interested too. What type of steel do you want to use for the 10mm plates that forms the magnetic field? Steel 413?
Yesterday i bought 50g/m*m an its very very thin. Now i wonder how to centrate the membrane with the elastic ropes. As an ideea the news paper has 35-40g/sqm...
The patents from bellow are the ones that i studyied for the rubanoid speakers:
1. 1929, Charles Hugh Duffy
Patent US1740161 - Device for the reproduction of sound - Google Patents
2. 1990, Paul W. Paddock, for the Lineaum Speakers (tweeter with the same principle)
Patent US4903308 - Audio transducer with controlled flexibility diaphragm - Google Patents
3. Some imteresting ideas also from Paul W. Paddock regarding these speakers
Paddock Paul W - Inventor Patent Directory, Page 1
I posted these patents just for learning purposes and newer ideas and NOT for selling.
1. 1929, Charles Hugh Duffy
Patent US1740161 - Device for the reproduction of sound - Google Patents
2. 1990, Paul W. Paddock, for the Lineaum Speakers (tweeter with the same principle)
Patent US4903308 - Audio transducer with controlled flexibility diaphragm - Google Patents
3. Some imteresting ideas also from Paul W. Paddock regarding these speakers
Paddock Paul W - Inventor Patent Directory, Page 1
I posted these patents just for learning purposes and newer ideas and NOT for selling.