big AMT Diy

[Charcoal]

In post #8 is something like Half of Rubanoide. May be it would be better to make it half-round, not flat?

[el`Ol]

Originally posted by Neil Davis


Why do you think there will be contraction?

My starting point was that for a large AMT the gap would be to big for the usual magnetic circuit, so my solution was that there are many gaps and every gap contains only one fold (picture in post 7). Result is nat neither of both movements (fold contraction vs. cylinder contraction can be neglected, so one of them has to be removed.

[el`Ol]

Originally posted by Charcoal
In post #8 is something like Half of Rubanoide. May be it would be better to make it half-round, not flat?

It would have to be calculated what solution is more linear. Voice coil centering is better in my solution.

[Charcoal]

What material you suppose to be used for such driver (like at your picture)?

[el`Ol]

Originally posted by Charcoal
What material you suppose to be used for such driver (like at your picture)?

Principally everything that is used for cone drivers. Maybe paper that is treated with a roller to do the foldings. Beware that paper has a fiber orientation. With aluminium or polymer I would glue textile on the stripes to do a flexible connection. Beware there is almost nothing that glues polypropylene. Best suited are probably modern compound-materials, e.g. aluminium with viscoelastic polymer or glass fiber mesh with Rohacell foam.

[Ed Holland]

Interesting thread.

It has touched on a few thoughts I have had upon how to take the advantages of a magnetic planar, but improve the dispersion.

One line of consideration would be to form the "panel" in a cylinder, so that it operated in a "breathing" mode. Obviously it might be hard to make a stretched membrane conform to a cylinder, so I reasoned that a pleated diaphragm might work.

In addition, since one would effectively be enclosing a volume with the cylinder, it might be possible to exploit this as a reflex or aperiodic enclosure and so gain better bass response.

Ed

[Charcoal]

I`m thinking about wide range unit:

1) Good highs dispersion, min. floor to ceiling reflections = tall and narrow planar;
2) Opened ensclousure(no box) = free, unboxy sound.
3) maybe bipole mode = magnets in the midle and film on both sides (maybe also magnets outside for push-pull mode) - does it look realistic??? (I mean bipole planar on opened baffle)

[el`Ol]

For a bipole search for "personal planars". But I have some doubts this design is really serious. Maybe the little hole makes enough dispersion itself and the foils have no function. In case it works I would use a compression driver from 800 Hz up. Some even work from 600 Hz to 20 kHz.
If a dipole is OK André´s design is proven and I am sure he will help you.

[ABJensen]

Originally posted by el`Ol
For a bipole search for "personal planars". But I have some doubts this design is really serious. Maybe the little hole makes enough dispersion itself and the foils have no function. In case it works I would use a compression driver from 800 Hz up. Some even work from 600 Hz to 20 kHz.
If a dipole is OK André´s design is proven and I am sure he will help you.

If you wont it to work. use four strips off alu, to get the impedans up. Then fold the ribbon like and W, with the foldings between the alu strips.

[Charcoal]

Thanks for joining, ABJensen. After looking around various ribbon / planar projects really consider yours one as one to be copied.

Pls, advice exact shape of foldings is W or UU?

Methode of suspension - just sides fixed in frame or something more complicated?

What Alu foil did you use and what impendance received?

Paper that you used - is it some special treated paper ?