KODA^2 – Optimizing the prototype

The KODA^2 – Optimizing the prototype

 

Since I made the prototype – I have done some optimizing of the design. It still looks the same on the outsize – but inside has been optimized with the correct sized bass port and 20% less material in overall. This makes them lighter and gives them just the right bass port directly from the laser cutting process. I feel that the weight of the KODA^1 is their only real downside and the new optimized design should issue this and make them below the acceptable 500 grams.  There was so many things that needed a bit of grinding in the prototype on the inside to fit the drivers and it has all been corrected on the KODA^2, making it a better and more polished product while including the almost countless optimizing I did on the prototype J (OK – not countless, but quite a few I assure you).

The background story of the KODA headphones is that I was following the ortho dynamic round-up thread on head-fi.com. That got me interested in making my own custom cans. I knew right away that the T50RP driver was just what I needed for my custom headphone project. A driver capable of delivering an extraordinary detailed midrange – with potential for delivering a fast and tight oomph in the bass region while maintaining detailed highs, without emphasizing  them too much. This was why I made the KODA headphones and you can read about that project here: http://diy.koenigs.dk/2014/02/22/koda1-koenigs-ortho-dynamic-acrylic-headphone/ 

The changes from KODA^1 to KODA^2

  • Nicer veneer – I will let you choose between a couple of types like walnut burr or zebrano
  • Nice thick black felt on the inside of the headband – very discrete
  • Minor tweaks and optimization to the inside dampening
  • Bass port micro-tuned for even bette balance
  • Less reflective, matte finish on earside of baffle
  • About 20% lighter
  • Reflective felt spot behind on back of cup

 

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I got all the parts and I have started making the first 4 units. I’m using a wood board with nails to control the pieces and to make sure they are perfectly aligned. This is only two units on this picture though.

 

 

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Three types of very fine veneer – not even varnished yet, but they are sanded with 400 grit. My favorite is the Macasser Ebony farthest to the right. The other veneers are Walnut burr and Australian Walnut.

 

 

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New and very improved baffle, unbelievable stiff and it’s matte polished to be less reflective and have a nicer feel.

 

 

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Australien Walnut – first finished cups.

 

 

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Matte polished with veneer almost completely polished away for a burned look. Then it is treated with bee wax. The polishing of the parts is a tiresome process and I have used almost 6 hours doing so.  But I think this is becoming my favorite look. I really love the look of the matte polished acrylics with bee wax. It feels fantastic too.

 

 

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Much smaller ball joints – I had to do some drilling to get the aluminium rods to fit. The result is a much lower weight and nicer and more balanced look, than on the KODA^1

 

 

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Baffles with the T50rp planar magnetic / ortho dynamic drivers and flet hole damping. Notice the silicone gaskets for air tightness.



 

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The last cups is finished – It’s the second from left, ebony.

 

 

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Internal dampening felt. The nuts will be covered with a reflex dot made in hard felt.

 

 

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Reflex dots. The felt with hole over the driver makes sure the bass is deep and the reflex dot lifts the treble a notch.

My hearing says it’s working beautifully.

 

 

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Closing the first cup – embedded screws and matte rough surface.

 

 

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Finally the first finished KODA^2 – IMHO it’s much nicer looking than the prototype and almost 100 grams lighter.

Very nice wiring, Neutrik plug and they are so comfortable.

 

 

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Ear side of cup (Australian walnut veneer cans)

 

 

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Some shots of the finished unit:  MACASSAR EBONY + Bee Wax  -  KODA^2

 

 

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Matte polished acrylic with walnut burr and bee wax  -  my own headphones

 


koda^2 mkII readings

Finally for some measurements, done after a lot of fine tuning. The light grey line is the KODA^2 before I got my test bench made and unfortunately it also the pair of headphones that was used for review.