Diy planarspeakers

[båndsei]

I have been working with planars a year and here is some models:

[The last one i made has curved membrane and curved panels as well:
[

 

[LineArray]

Hallo bandsei,

your models look very professional and elegant.

Would you like to tell us something about the way they
are driven and the materials used ?

What is the typical lower frequency limit ?

Kind regards

 

[båndsei]

They are driven with a class D amp app. 250w in 4 ohms.Crossover 150 hz. 24 db. electronic filter.
Magnets are neodymniun 10x6 x70mm. Membrane are made of alufoil on paper taped with microporretape.

 

[LineArray]

So i suspect the current flows vertically through the
ribbon like conductors, which are row circuited ?

The magnets are on the rear of the membrane only ?

Membrane glued directly on the magnet structure
possibly using some suspending/damping layer
in between (this is your microporretape) ?

Sorry if a ask too many questions ...

Can you describe how they sound, compared to
other kinds of systems you know ?

What are virtues, are there drawbacks you know ?

 

[bentl]

Hi bandsei,

could you please share some mor photos? Wold like to see some closeups and possibly a picture from the rear.

Regards,
Bent

 

[a.wayne]

Hello bansei ,

Another good looking planer with your special metal work ...


regards,

 

[båndsei]

Here is some pictures.They are not from the same speaker but shows some details wich are the same for more models.

Hope the pictures anserves some of yours questions.
Theese are the best speakers i have had.

 

[tinitus]

And yeah, they do sound sweet

 

[jrubins]

wow! very cool.
Where do you get your supplies?
I'm looking for a source on the aluminum/papertape combo and the neodymium magnets bars.

Have you tried any push-pull magnet arrangements or do you always place the magnets on the back side?

Those look great!

 

[chinsettawong]

Nice work, indeed.

Show us more pictures, please.

Wachara C.

 

[båndsei]

I buy my magnets here:Welcome to HYAB Magnets
The alu/paper from a supermarket named "Kvickly" in the Coop group.Verry common here in Denmark.The alufoil is 0.007mm. thick.Microporretape from 3M.
I cut the alu/paper and microporretpe to smaller sizes 12.5mm 4 mm and 9-10mm for the alufoil.I use app.6 meter alu/paperfoil wich results in 4 ohms for the speaker.
Here is a picture that shows how i make the "rools"

 

[jrubins]

I like your DIY lathe, too

 

[bentl]

Hi, impressive design and finnish!

Could you share some more info on magnet sizes, arrangement, layout of magnet and supporting plate? What is the distance between diaphragm and magnets?

I'm looking forward to a few days in the workshop during christmas and the outcome will hopefully be a pair of electrostats but I may also find some time to experiment with magnets.

Regards

Bent

 

[arend-jan]

I love the looks of your panels, especially the curved ones. How do you make such a curved panel? I mean the woodwork. I'd like to learn how to do that myself.

 

[båndsei]

Here is more pictures:

First i tape 2 10mm alufoil with 4-5mm. microporretape.

Then i "corrugate" .The ribbon is app. 6meters.

The frame.The magnets are mounted with the same polarity to ease the layout of the alufoil.The magnets are glued to a 5x10x1200mm.iron. the distance betwine the magnets is 12mm.
The membrane is supported in 5-6 places by rubber.The distance betwine the membrane and the magnets are 2-3mm.

 

[bentl]

Hi

thanks a lot for sharing! It seems like you have a very diy-friendly approach to this.
My concern has been working with large metal plates as I will have to order them to measure - and that is expensive!!

But iron rods I can cut and weld no problem. But first; electrostats! I have all parts ready to assemble, but I am very tempted to try a magnet dipole as well.

Seems like there is fewer parameters involved in magnet dipoles, no hv power supply, no step-up trafos and no coating.

But I have been wrong before...

Thanks again for sharing, most impressive work!

 

[båndsei]

I am going to sell some of my old "frames" without magnets or membranes.
Look in swap meet.

 

[LFM]

DIY Planar

I am fascinated with your speakers and technics. I am curious about the foil you use and would like to find a North American source. The closest thing I have seen to it is used in cigarette packages to keep them fresh and the wrapping for expensive chocolates. The foil is dead soft and the only way to separate the foil from the paper is to burn it off. Am I correct to assume that this describes the foil you use. By the pictures you sent, it looks a bit like the tape that is used for ducting, heating and air conditioning systems. I'm sure this isn't right as the foil is too thick and held to the backing with pressure sensitive adhesive. As you know, the paper backing is removed before applying. Albert

 

[tinitus]

I am curious about the foil you use

Lunch paper, sandwich paper

No joke, it really is, and it actually sounds good

Båndsei shows you how he use a small drill as lathe, and cut small rolls with a knife, or what you like
Then its just to lay it out in the pattern you need, and tape it all together with slim tape, from rolls cut the same way

It looks simple, but takes practice, and my guess is that båndsei may have made about a hundred diaphragms by now

 

[LFM]

DIY planar

Tinitus, I have never seen the foil paper in Canadian supermarkets. The Arby's chain uses it or something similar to wrap their beef and cheddar sandwiches. I'll call around to some commercial restaurant suppliers to see if I can find a source here and post my results. I live on the Canada US border and will have a look in Michigan on my next trip over. I would like to add for the benefit for those who don't know; there are more pictures and discussion of these planars in the DIY ribbon thread started by Dr.Henry P. found on page 2 of the forum.