Hi Roger
Have you seen this Mag factory tour
Magnepan Tour
Some of the pictures shows diaphragms which seems to be self supporting!?
But I have also been thinking how they could get enough tention if not supported to the steel plate first.
When I did my prototype I did it the exact way you describe.
With regards to glue, I think some of the 3M tapes will do quite well ...
Kind regards Baldin
Have you seen this Mag factory tour
Magnepan Tour
Some of the pictures shows diaphragms which seems to be self supporting!?
But I have also been thinking how they could get enough tention if not supported to the steel plate first.
When I did my prototype I did it the exact way you describe.
With regards to glue, I think some of the 3M tapes will do quite well ...
Kind regards Baldin
Hi Baldin,
Yes, I have seen that page before. All the pictures were download years ago.... Where do you see self supporting diaphragms? The drivers are more less self supporting but they can bend if removed from the frame but seems to lay down flat.
This picture shows the perforated sheet metal with the magnet bars attached, waiting for the spacers.
http://www.paulspeltz.com/maggie/magnets.jpg
This picture shows a driver with the Mylar mounted and another one still without.
http://www.paulspeltz.com/maggie/mylartable.jpg
Roger, long time owner of Magneplanar Tympani
Yes, I have seen that page before. All the pictures were download years ago.... Where do you see self supporting diaphragms? The drivers are more less self supporting but they can bend if removed from the frame but seems to lay down flat.
This picture shows the perforated sheet metal with the magnet bars attached, waiting for the spacers.
http://www.paulspeltz.com/maggie/magnets.jpg
This picture shows a driver with the Mylar mounted and another one still without.
http://www.paulspeltz.com/maggie/mylartable.jpg
Roger, long time owner of Magneplanar Tympani
Hi Roger
Yes that was exactly what I was looking at ... Well the picture detail is not good, and I made assumptions from what I know .... now I see that the long dark lines are thin megnets and that the green stuff is the metal sheet, and what seems a bit darker green is actually holes in the metal sheet ... right?
.... I thought it was the diaphragms ... and thought they looked quite strange indeed ...
Thanks for the information
/Baldin
Yes that was exactly what I was looking at ... Well the picture detail is not good, and I made assumptions from what I know .... now I see that the long dark lines are thin megnets and that the green stuff is the metal sheet, and what seems a bit darker green is actually holes in the metal sheet ... right?
.... I thought it was the diaphragms ... and thought they looked quite strange indeed ...
Thanks for the information
/Baldin
Still trying to get my head around what questions to ask, mostly.
Has anyone experimented with many (or any) different magnet and/or conductor geometries?
For example, what does the trade space look like for magnet width, column spacing (i.e. horizontal spacing between vertical columns of magnets), and number of columns?
Along the same lines, what about the conductor geometry? How is the magnetic field most efficiently utilized? What are any other considerations?
What about leaving gaps between magnets within a column? e.g. What about something like 1/2-inch square magnets with 1/2-inch (or whatever) gaps, instead of no gaps in a column?
What about varying the magnet spacing (or strength) or the conductor geometry, depending on how far from the edge of the membrane? It seems like, nearer to the fastened-down edges, we might want more actuation force on the membrane, to try to help the membrane move as a more-unified plane instead of having the middle always move farther than the areas nearer to the edges, for a given current.
By the way, has anyone done even a quick-n-dirty trade-space study comparing electromagnets to permanent magnets? It seems crazy, I guess, unless there is some dirt-cheap source of electromagnets, or their major components...
I am getting some magnets and will try to expriment with etching some metallized or metal-laminated films and report back. It will probably be at least two or three weeks before I have any results at all, and maybe significantly longer. But if I can find a metallized film or laminate that has good-enough electrical properties and that is easy-enough to print and etch, etc, it could then make it pretty quick to experiment with (and produce) many different conductor geometries. And if, for example, it turned out to be better to have zillions of tiny conductors, it wouldn't be significantly more difficult than having only a few larger ones, as far as actually creating them on the membrane is concerned.
Cheers,
Tom
Has anyone experimented with many (or any) different magnet and/or conductor geometries?
For example, what does the trade space look like for magnet width, column spacing (i.e. horizontal spacing between vertical columns of magnets), and number of columns?
Along the same lines, what about the conductor geometry? How is the magnetic field most efficiently utilized? What are any other considerations?
What about leaving gaps between magnets within a column? e.g. What about something like 1/2-inch square magnets with 1/2-inch (or whatever) gaps, instead of no gaps in a column?
What about varying the magnet spacing (or strength) or the conductor geometry, depending on how far from the edge of the membrane? It seems like, nearer to the fastened-down edges, we might want more actuation force on the membrane, to try to help the membrane move as a more-unified plane instead of having the middle always move farther than the areas nearer to the edges, for a given current.
By the way, has anyone done even a quick-n-dirty trade-space study comparing electromagnets to permanent magnets? It seems crazy, I guess, unless there is some dirt-cheap source of electromagnets, or their major components...
I am getting some magnets and will try to expriment with etching some metallized or metal-laminated films and report back. It will probably be at least two or three weeks before I have any results at all, and maybe significantly longer. But if I can find a metallized film or laminate that has good-enough electrical properties and that is easy-enough to print and etch, etc, it could then make it pretty quick to experiment with (and produce) many different conductor geometries. And if, for example, it turned out to be better to have zillions of tiny conductors, it wouldn't be significantly more difficult than having only a few larger ones, as far as actually creating them on the membrane is concerned.
Cheers,
Tom
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Hi Båndsai
First, why do you wnat to bend it? Do you have problems with vertival dispersion?
the bending is used in Fibonacci as the ribbon is not tall enough to be a line source, and way to long to be a point source. Bending gives a better dispersion.
How low does it go?
I guess you have had to stretch the film somewhat more to make it work in the bended shape. This will give a higher resonance frequence. Remember that free air resonance is determined by the moving mass and the suspension compliance (spring mass load).
Wider and closer to the floor will help. But why not just make a straight version which is real line source ... like 180 tall or something ....
How low does it go?
What strength dou you strtetch the film with?
But as always, really nice build
Best regards Baldin
First, why do you wnat to bend it? Do you have problems with vertival dispersion?
the bending is used in Fibonacci as the ribbon is not tall enough to be a line source, and way to long to be a point source. Bending gives a better dispersion.
How low does it go?
I guess you have had to stretch the film somewhat more to make it work in the bended shape. This will give a higher resonance frequence. Remember that free air resonance is determined by the moving mass and the suspension compliance (spring mass load).
Wider and closer to the floor will help. But why not just make a straight version which is real line source ... like 180 tall or something ....
How low does it go?
What strength dou you strtetch the film with?
But as always, really nice build
Best regards Baldin
hey, your 'shop' is growing
looks cool
dont forget diaphragm ressonance(Fs)
its about size, and tension
that determines how low it plays
your curved design is in reality multiple small mid/tweeter modules
I want to bend it for two reasons.To get better dispersion,so that I don´t need to sit down to get top performance, and i hope I would get less niveau at top.I realy would like to make a fullrange planarspeaker,but it seems that with a normal ,not bend,diaphram the niveau at top raises with the width.
I usaly tries to tune the membrame to 40-50hz. messured with "Limp".
I want linar output to 80-100hz.That´s possibly with my 2 way model.
Bernt "Båndsei"
I usaly tries to tune the membrame to 40-50hz. messured with "Limp".
I want linar output to 80-100hz.That´s possibly with my 2 way model.
Bernt "Båndsei"
Hi Bernt
Have you considered to just eq to a good frequency response?
I guess you want to use a sub for the very low end.
I have seriously considered to try our one of the miniDSPs .....
Even B&G modules meed eq (normally in the form of a passive broad notch filter).
But using a DSP, makes this really easy and super for work with "prototypes".
And again, just make it higher to get good dispersion, both sitting and standing ... it's only a little extra cost
Best regards Baldin
Have you considered to just eq to a good frequency response?
I guess you want to use a sub for the very low end.
I have seriously considered to try our one of the miniDSPs .....
Even B&G modules meed eq (normally in the form of a passive broad notch filter).
But using a DSP, makes this really easy and super for work with "prototypes".
And again, just make it higher to get good dispersion, both sitting and standing ... it's only a little extra cost
Best regards Baldin
I plan to build a couple of planars or Big Heils to match the following quasi dipoles or as they are also called "Ripoles"...
Then the PMD must have a very high power handling, 200 Hz to as much as possible frequency range and very low distortion. Any suggestion welcome !...
Then the PMD must have a very high power handling, 200 Hz to as much as possible frequency range and very low distortion. Any suggestion welcome !...
Attachments
Bändsai,
What is the SPL output of your planars ?
Perhaps you already answer somewhere to this question, sorry for asking again if it is the case, and just give me the link...
Second question is about the "membrane" or "ribbon" : if we use some conductive coating with very high resistivity (say 10^10 or 10^12 ohms per unit square) like on ESLs, instead of an adhesive tape of aluminum, is there any chance to get a working device ?
TIA for your answers...
What is the SPL output of your planars ?
Perhaps you already answer somewhere to this question, sorry for asking again if it is the case, and just give me the link...
Second question is about the "membrane" or "ribbon" : if we use some conductive coating with very high resistivity (say 10^10 or 10^12 ohms per unit square) like on ESLs, instead of an adhesive tape of aluminum, is there any chance to get a working device ?
TIA for your answers...
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Where do you get your stands from Bandsei? They look quite nice and light! Do you make them yourself? You seem to be good at woodwork as well, unlike me, I have to cover my planars, because of the rubbishy woodworking. Still the main thing is the sound. I live on my own so appearance is not so critical.
The woofers used in my Ripoles are also Dayton 12" (RSS315-OH4). Then my project is to build a couple of planars going down to 200 Hz... Let me know how I must proceed to reach this frequency range (i. e. 200Hz to 20 kHz or so), with very high power handling ?
Are all the frames interconnected ? I mean are the supports of the magnets attached to each other ? Then, is there a method to theoretically derive : the number of magnets, the distances, the SPL and so on ?
Last, if I would go for a push pull model do you have any tips to face the two sides of the driver ?
For example, the LS4 from Wisdom Audio with more than 1600 magnets needs 12 tons to press both sides to each other...
TIA for any help !
Soe times i dont see all the questions asked too me.
Baldin, you asked if i tried EQ.Yes ,i use Mini DSP for crossover and EQ the sub.I have tried to EQ the planar too,it works ,but I´d rather not.
Ondesx,you have got a lot of questions.You can use FEMM to optimise magnet fieldstrength,but it take time to lern it right.
My best advise at the time is ,use neodumnium magnets,not thickker than 6mm ,I use 6x10x70mm., app 100 pc.for one speaker.
Use EQ to decreace niveu at top.
Bernt
Baldin, you asked if i tried EQ.Yes ,i use Mini DSP for crossover and EQ the sub.I have tried to EQ the planar too,it works ,but I´d rather not.
Ondesx,you have got a lot of questions.You can use FEMM to optimise magnet fieldstrength,but it take time to lern it right.
My best advise at the time is ,use neodumnium magnets,not thickker than 6mm ,I use 6x10x70mm., app 100 pc.for one speaker.
Use EQ to decreace niveu at top.
Bernt
OK Thanks Bernt for this advice. Do you ever try to build a push-pull ?
Otherwise did you tried pleated membranes like in the AMT instead of stretched Mylar ?
Wow, just beautiful man.
You have some Industrial Design talent as well as engineering talent - a rare combination.
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