[CoffeeCutie]

https://3dwarehouse.sketchup.com/model.html?id=a31ee6df-5708-419b-94a0-15d64f2c1c7b
 
...So, we begin!
 
I am beginning my process of building a planar driver headphone, ideally in tandem with the electrostatic build.  They share construction principles, but the ES driver requires a fairly expensive amp build- which will take extra time, cash, and thought.  So the planar is up to bat first.
 
This is my planar v2 design.  it employs a two 2x4 arrays, sized 1x1/4x1/4 inch each, encasing a membrane (such as saran wrap, kapton, mylar, the usuals) with a thin etch of RFI tape or otherwise very thin copper tape.  I will 3d print these chassis and housing parts, because that is a tool I have easy access to.  the wooden cup may require a CNC trip, because CNC'd cups are snazzy.   The overall cost is low; the amp can be simple (simpler that is); the parts can be emulated with ebay-able and sometimes amazon-shippable items.
 
I am toying with the ES and dynamics too.  Assuming I remember to write updates and don't unearth the possible fact "it can't be done" I may venture into these other operating principles too.    
 
Happy Building!

 

[CoffeeCutie]

Source code didn't work
 
Pictures instead I guess:
 

 

 

[CoffeeCutie]

Well, Hmmm.  I let my University's "tech" people do my initial chassis print.  They did a unusably poor job, so I decided to take the chance to redesign the driver for v3.   I used these bulk chinese magnets for a new size.  I assume they are axially magnetized such the 3mm sides are polarized.   Because the whole ebay shipping thing can take a while, I will likely not be able to make headway for a while.   24 magnets per driver is quite a few, thus these bulk cuboids seem like the way to go.  I plan to print v3 with as much control I can convey/access the university's printers, or just wait and get certified at a makerspace, if I can muster a field trip to Boston. 
 
Here is the useless driver assembled: 

 
Here is v3: it Can be found here: 
 

 
The plan is to not worry about about baffles/cups, gimbals, earpads (though as I said, audeze LCD will work in a pinch) or headbands before the driver is in good standing.  
 

 

[witkep]

Hi,
 
I am new here, for some time I was looking around for information about diy planar headphones. I did myself pair, actually current version is revision no.4
If you are interested I am more than happy to share more about design. In few words it is sandwich design cnc machined from 3mm plexiglass, magnets are comparable to those which you intend to use but longer(40mm).  
The tricky part which I spent most time was membrane. I also tried etching but it was very complicated and nothing close to thin as result. I switched to this design:
base - 3m car window tint thermo shrink foil - but not heated
voice coil - 3x5 rounds of 0.05mm copper wire
top - cling foil to distribute pull force of wire 
What I found out during working on this project is that when I support membrane only at two sides of frame mids and higs are more clear, but it requires som additional damping at unsupported sides to decrease bass.
I compared those to audeze, oppo and hifiman products. Only during audio-video show so I had only some impressions:
- bass - too much without damping - but comparing to my akg 240 it is not so intense
-mids  - clear and crispy
-highs -  need to work on
I attache some photos:
https://goo.gl/photos/triHsZDfMtDYKEcs7
 
Thanks and wish luck with your design!

 

[CoffeeCutie]

Hi Witkep!
 
Those are great!  Ingenious membrane there.   If you haven't already found it, I highly recommend Wachara C.'s giant DIY electrostatic thread here. I am finagling those membrane designs, and have some 3 micron mylar on the way for stretching.  Will it work as a planar membrane?  No idea!  I'll find out.    Very interesting about the low end bassiness you found- when I used cling foil in a broken dynamic driver (as a complete replacement to its cracked plastic membrane), it also had uneven/bloated bass.   This extra bass vibration quickly distorted, flapped against the housing, and then blew out all together.   Hmmmm......

 

[witkep]

Mylar sounds nice especially 3micron, 3m fx foil I use currently is around 20micron. And I found that mass has very big impact, I felt huge difference when I used 2x5 voice coil versus 4x5. For 2x5 highs and mids are great but my amp has hard time to provide power for bass. Where do you get mylar foil? And how do you plan to glue it?

Wysłane z mojego Nexus 5X przy użyciu Tapatalka

 

[witkep]

Mylar sounds nice especially 3micron, 3m fx foil I use currently is around 20micron. And I found that mass has very big impact, I felt huge difference when I used 2x5 voice coil versus 4x5. For 2x5 highs and mids are great but my amp has hard time to provide power for bass. Where do you get mylar foil? And how do you plan to glue it?

Wysłane z mojego Nexus 5X przy użyciu Tapatalka

 

[CoffeeCutie]

I got my mylar from ebay- the seller's name is audio.01 (based in Taiwan it says).  I have DAP contact cement but I hear there are better options out there from the electrostat people.  the contact cement may be to finicky and quick drying...  We'll see!  I built a first draft inner-tube stretcher today, but other than that it's up to the shipping waiting game from china before I can make headway. 

 

[CoffeeCutie]

I just wanted to update this thread-  I have built two very shabby drivers, visually and functionally not worth posting here. I need to work on the transfer method for the adhesive copper tape...  I tried just "stickering" it on first, which seem logical but it really got kinked and crumpled due to the extreme thinness and finely cut trace shape.  I got it to produce some steve vai, but it was weak and barely hanging in there.  I did an electro-etch trace, but again the process needs to be refined (my opaque trace was not opaque enough for the salt etch) ...I intend to try a few coats of matte nail polish next time, both for the thickness and density of nail polish and that I can remove the trace mask with polish remover.  That driver was even weaker.  The 3d printed models need some refinement too; the warpage/shrinkage of the plastic is notable.  I believe I needed a better infill pattern and percentage.  I am using my university's 3d printers, so the route to using them is rather circuitous and takes a while. 
 
I took the embroidery hoop idea posted from elsewhere on the forum for membrane stretching (I go me a set of smooth plastic ones), and will by using a tuner app to "tune" the stretch of my next membranes.  What a great idea that fellow had!!
 
I did notice the volume got quite a bit louder when I offset the one magnet array to be completely opposing the other, such that the arrays were staggered.   
 
I have a number (50?) of small button magnets.  These are interesting as they exhibit greater strength than the bar magnets, and have a distinct polarity/shape thing going on.  I will likely be designing a chassis for those next.  
 
Features should include:
 

1. conical "fazor" shapes to act as extra supporting structure as well as provide possible acoustic enhancement
2. re-buildable chassis (no glue) to test different membrane and array shape combos (bolts)
3. circular membrane with properly (nail polish?) etched trace
4. switchable "LCD-2" and "LCD-3" array layouts - as in parallel and opposing vs. staggered and opposing.   this could be achieved with an offset rotation of the array.
5. investigate a quasi-disposable connector to use for hooking up different membranes during testing.  

 
Yay!