My DIY Planar Magnetic Headphones and Drivers
Oct 2, 2012 at 2:35 PM Thread Starter Post #1 of 19

euwemax

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Hi All,
 
I have just completed another DIY project of mine and I thought I'd just share it with everyone. So here's the story, I always wanted a pair of planar magnetic headphones but I am broke and I couldnt put down any money for them, so I decided to DIY my own pair of planars and drivers based on the information I found around the internet. I guess some might not consider these to be "true" planar magnetics since they only have one set of magnets below the membrane as opposed to some which have two sets, one above and one below the membrane. Sound wise they are not perfect, but I would say it turned out better than I expected.
 
Pictures:

The completed headphones, I used a collapsing earmuff which I found on amazon. I removed all the stuffing and put the drivers inside.
 

Here's the view from the inside, there is one rectangular driver per side, each measuring about 6 x 4 cm.
 

A view of my DIY planar driver, It has 7 rows of n50 neodymium magnets arranged with a thin membrane which has aluminium traces running perpendicular to the magnetic field. The black lines are actually aluminium traces which I have covered with a black marker pen (more on that later). For the membrane I used ordinary plastic cling film.
 

Here is the back view of the drivers, I had to use a clip to bind the wires to the membrane as I could not solder the wires onto them because the cling film cannot withstand the heat of the soldering iron. I used a metal plate glued onto a piece of acrylic as the frame for the magnets to sit on. I did not use a full metal plate like some others because I wanted to reduce the weight of the drivers.
 

This is how the membranes look like underneath. The width of each aluminium trace is about 1mm and the separation between each trace is 1 mm. I am using the episilon layout which was implemented so well by Henry of Diy audio (http://www.diyaudio.com/forums/planars-exotics/200038-analysis-epsilon-17.html). Out of making the headphones, I found this part to be the most difficult, as most of the resources available for the membrane are for full sized speakers which involve cutting thin strips of aluminium and sticking them manually to the film. I tried that approach but I could not go below 2 mm and unfortunately with my less than dextrous hands I cannot align them parallel to one another. That resulted in a really bad membrane, so I came up with this method to make the membranes by etching the aluminium foil.
 
 

Here is how I made the membrane, I glued a piece of aluminium foil to the plastic cling film which I wanted to use as the membrane. Then I used a permanent marker to draw the pattern of the aluminium traces which I would like to keep. The marker acts as a mask which protects those regions from being etched. After that I soaked the membrane into ferric chloride (pcb etchant) and it would dissolve all the aluminium except for the masked parts, producing the membranes.
 
Thats all... thanks for reading =).
 
Oct 3, 2012 at 10:40 AM Post #5 of 19
Congratulations on your success and thank you very much for sharing how to make your headphones.  It is very interesting.  I have a pair of broken HE-5 and I'll try to make the diaphragms the way you did.
 
Wachara C.
 
Oct 16, 2012 at 11:23 PM Post #6 of 19
Between this and the DIY electrostatic headphone thread, I have a lot of fun research and development ahead of me.
 
Oct 26, 2012 at 10:21 PM Post #8 of 19
super cool!
 
what is next? Speaker panels
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Jun 26, 2013 at 5:19 AM Post #10 of 19
This is Henry, thanks for the mention. I have actually managed to stick 1.5 mm tape onto my latest headphone builds using full range  planar designs. The first 2 I built used cheap headphones I bought, stripped out the speakers and replaced with my neo driven diaphragms using 2.25 mm alu tape cut by hand. The 3rd one used 1.5 mm tape cut by hand using my epsilon variation, a bit fiddly but managed it. These headphones were a bit too small for building in. Seeing how you did the etching, made me want to try the same. Would be a lot easier than sticking it on by hand, although I have had a lot of practice on my over 60 builds in the loudspeaker DIY FRP scenario.
 
Jun 26, 2013 at 5:29 AM Post #11 of 19
I have still got quite a few magnets left mostly ferrites, although I do have about 140 50 x 12.7 x 6 mm neos, I haven't made my mind up yet what to do with them. I have bought several cheap headphones so I can use them to build more FRP type headphones using the shells. May use etching and my epsilon variation for the diaphragms to get more sensitivity. which is a bit low with the normal layout, we shall see.
 
Jun 26, 2013 at 5:43 AM Post #14 of 19
Quote:
how does that sound i'm about to attempt my own build of a planar headset i just need to find a decent sized donor shell..

Use a large cheap headphone like I do, you end up with a good looking design using the cheap carcass! It is best to use the largest you can get with a well padded headband. Get the U shaped swivel type easier to use than those with the bent rod insert, the plastic inside is easier to use, for the diaphragm support.
 
Sep 29, 2013 at 8:19 PM Post #15 of 19
  Use a large cheap headphone like I do, you end up with a good looking design using the cheap carcass! It is best to use the largest you can get with a well padded headband. Get the U shaped swivel type easier to use than those with the bent rod insert, the plastic inside is easier to use, for the diaphragm support.

 
ok thanks for the tip i have decided to go with a 80 mm round because it was a cheap buy and it looks as it will do well... I have yet to find the proper aluminum foil sheets that i would need to make my driver traces.. Is there anywhere i could get like 8 1/2 x 11 1/2 sheets with adhesive backing?? I'm having a tuff time finding that in which i need.. 
 

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