Diy planarspeakers

[Baldin]

For example, the LS4 from Wisdom Audio with more than 1600 magnets needs 12 tons to press both sides to each other...

Maybe go for a littel less than 1600 magnets at the first prototype

12T sounds like quite a lot!!!
I used 48 NEO magnets for my 50 cm prototype these are 2 mm thick and 5 x 20 mm ..... yes you have to push a little to get front and back panel together ...... and be very carefull not to disalign them .... if they at any ponit get to be magnet over gap they will attract each other very hard and very fast .... don't get your fingers between


For push pull, take a look at some of the patents like US4037061A1 .....
basically you just place it like this:

NN SS NN SS NN SS NN
SS NN SS NN SS NN SS

SS NN SS NN SS NN SS
NN SS NN SS NN SS NN



Bernt why don´t you like to use the miniDSP for EQ? .... does it not sound right??

Best regards Baldin

 

[båndsei]

Planar theory
Here is a better description of push pull magnets .

Mini DSP sounds fine ,it´s just that Iwould rather make the speaker right ,than EQ it.
My next attempt is oneway with EQ. 150 mm.wide, 1200 mm. long
I dont have a good picture of my push pull model,maybe a draving.

Bernt Båndsei.

 

[ondesx]

Maybe go for a littel less than 1600 magnets at the first prototype

12T sounds like quite a lot!!!

Yes ! I'll probably begin with much much less magnets !...

For the LS4/12 tons see here :

Wisdom Audio Series LS4 and LS3 Speakers First Look — Reviews and News from Audioholics

One question to everybody : for the Mylar (or more generally speaking the membrane) how do you regularly stretch it ? And then, how do you fix it all around ? With time, doesn't the membrane make any pleats ?

Thanks...

 

[ondesx]

Planar theory
Mini DSP sounds fine ,it´s just that Iwould rather make the speaker right ,than EQ it.

Thank you for the link, I had already read it... Anyway, I think you are right to try to derive "the best non corrected driver". It's always time to do some little corrections then. With the softwares at our disposal on computers I think it isn't necessary to use more hardware devices ! Now, you can use several plug-ins on the same host with really a great number of equalizers, graphic and/or parametric. The same way you can measure the response of your drivers !...

But, I personally think that the correct frequency response of a driver is less than half the way for a good one. It's the same for an amplifier to sound good if the frequency response is, say perfect... In this latter case, the quality of the attack-release are equally of great importance ! For example, if we perform the Fourier analysis of an audio signal, say of good music, we'll find the same result on the reversed version of the signal, but if we listen both the non-reversed and reversed, I'm sure we would be more comfortable with the first one !...

 

[båndsei]

http://www.diyaudio.com/forums/planars-exotics/50162-another-diy-ribbon-thread-49.html
here is a drawing showing my idea of a n other push pull planar
Bernt.

 

[JAMESBOS]

built several push pulls with the 2 membranes,but have decided against them as I can get as much sensitivity using just 1 membrane and half the magnets . The new membrane is only .02 as against the .1 of the 2 membrane design.
So I have to rebuild all my designs using the thinner polythene membrane, I have some polyester (mylar) membrane material, which is quite brittle and easy to split compared to the polythene material.
To get even higher sensitivity I will have to get neos about 5 mm wide so I can get more lines on the membrane, but rebuilding using the thinner membrane will keep me busy for now.

 

[ondesx]

http://www.diyaudio.com/forums/planars-exotics/50162-another-diy-ribbon-thread-49.html
here is a drawing showing my idea of a n other push pull planar
Bernt.

I understood your idea. Well, in this case you have one set of magnets and two membranes moving. In the "true" push-pull you only have ONE membrane with 2 series of magnets. One series pushes the membrane, while the other series pulls it.

To be honest I don't know which of either method is better than the other ! Probably the more the magnets the higher the level and I'm not sure that the "posterior" membrane works as good as the "anterior"...