Freely accessible modular headphone platform introduction

Hello everyone,

My name is Tomislav, I’m a headphone enthusiast, a long-time audiophile, currently a university medical student and a hobbyist headphone designer/DIY-er from Croatia with a dream of having my own headphone brand one day. I’m making this post in order to present the project I’ve been working on for the past almost four years in hopes that the community will like it and make good use of it, and with a bit of help, it may just help me get one step closer to making that dream become reality.

Let’s get right into it. I’ve been working really hard on the process of developing my own platform of fully modular headphone designs that could be used for various purposes, from DIY to series production, by combining my own custom designed headphone parts with existing accessories that can already be bought on the market. My goal has been to end up with headphones that would be very competitive in that mid to high-end price bracket between $400 and $900 and could be easily built for that sort of cost, depending on materials and accessories. The project introduces several new ideas and concepts, utilizes the most advanced materials and state-of-the-art industrial 3D printing methods, while also relying on traditional craftsmanship and meticulously building products by hand. In addition to that, all of the headphones have been designed from ground up with lots of built-in customization features, and I’ve generally been focused on making headphones behave like very flexible modular platforms, rather than fixed products. It’s been a single-person endeavor from the start, with a limited budget, and working on it alongside being a full-time university student has made it extra difficult, but I’ve taken it very seriously and really wanted to develop it to a high level, hitting all the development goals before releasing it to the public.

The project is now ready to be revealed in its entirety, and I want to do that in the most transparent and open way possible. In my situation, as someone who has a lot of plans for the future related to designing and building headphones, but is currently entirely unknown, I believe that’s the best way to approach the community. For that reason, the project is very much focused on involving the community, and the most attractive part of this is the fact that I’m making a huge portion of the project available to everyone for free, including fully developed and production-ready raw CAD files of two entire, fully modular headphone models that anyone will be able to use non-commercially in order to 3D print or CNC machine parts and build their own headphones , by following what I’ve done, or by further modifying the designs. This allows you to skip an enormous amount of work and save a lot of money you’d otherwise spend on conceptualizing, designing, R&D, prototyping and testing of a new product, and allows you to go straight to manufacturing. This could be a game-changer and a massive boost to the activity of the DIY community, and at the same time a good way for me to demonstrate my work and hopefully show the potential of things coming in the future. I think something like this is unprecedented, could inspire a lot of existing or new DIY-ers to spring into action and I believe it has the potential of developing into a sort of a headphone equivalent of the O2 amplifier, where multiple people could build their own versions of the headphones with a great cost/performance ratio.

You can download the CAD files for free from my website, and also read a bit of additional info regarding what you need to use the files. For any additional questions, feel free to contact me and I’ll answer ASAP.

I’ve gone through a lot of testing and developing over these last few years to make sure I’ll end up with something competitive, and have built multiple iterations of prototypes, including the final production ready ones that I’m presenting. In addition to that, since a project such as this is bound to be met with some skepticism, I’ve done my best to describe and document every step of the way and have collected hundreds of photos and renderings, as well as hours of videos showing various stages of development that can be found on the project website. I’d be very grateful if you’d visit it and let me know what you think.

I’ve also prepared a PDF file that contains the project described in great detail and neatly divided into chapters, which should provide a decent overview and be a good source of info. Please have a look and go through it if you’re interested, as it’s impossible for me to cover everything about a project this large in a single post. I know it’s a bit long, but it’s a big project with a lot of work behind it.

PDF file download (~9MB, 90 pages)

You’ll find two headphone models described in the PDF, the V1 and V2 , both finished and fully developed. A third model, V3, is in very late stages of development, but not yet ready for release, and you can find information on it on my website. Let me know what you think, and if you have any questions, feel free to ask here or contact me privately, especially if you’d like to get involved in the project. In any case, look at the current stage of the project as only the beginning, not the end, as plenty of new things are coming in the future.

This project has been in the works for a long time, but I’ve only just started to present it and trying to introduce it to as many headphone communities as possible to make it grow and develop further. If there will be those who’d like to build headphones but not mess with producing parts on their own, I’ll also be able to provide parts in DIY kits, and even build custom headphones entirely, just let me know if that’s something you’re interested in. In addition, if you have some good ideas or plans, or you’d like to collaborate and work on the project with me, hit me up.

Let me know what you think, and don’t be afraid to share suggestions or constructive criticism.


All I have to say is. Wow.

I see a big potential in what you are doing. Keep it up!


Thanks! Hoping to see a few people join up more actively, let’s see some headphone building competition between DIY-ers. :wink:


Just downloaded the files. Will try to print them out on an FDM printer to see how far I get.

I’ll let you know how it turns out.

Try it out, let me know how it went. Tolerances are super tight since it’s designed for SLS, but some simpler parts might turn out close enough to fit with some sanding.

I definitely will!

Also, I noticed you mentioned that the .ipt files needed to be opened in inventor.
I was able to import them into Fusion 360 no problem. Which is astonishing considering my previous experience with autodesk file compatibility lol.

I appreciate you providing the actual part files instead of just STL files as well.

Forgive me if you’ve already said, but what would you recommend as far as drivers and earpads go?


Yea I always forget to mention Fusion, it can open ipt. files as well. As for drivers and pads, depends on which headphone you’re building.

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Alright, I had a crack at printing them on an FDM printer and used some drivers that I got out of a pair of cheap AKG’s and some spare screws.

They’re very bright and sharp sounding. Any tips on how I can quell the highs?

Edit: So far I’ve tried dampening foam behind the driver and in front of the driver. I’m gonna move the driver 3mm closer to the ear and see how that effects the sound signature.

Apart from the brightness, they sound very good. Really looking forward to modifying them!


There’s your problem. Cheap drivers sound cheap regardless of the chassis. There’s only so much that can be done.

Swap the drivers or use dense cotton or felt filters, as you’ve already tried foam. Dan Clark provides a range of filters with different thickness and density. I find they make the sound ‘cottony’ or ‘wooly,’ but they do cut the highs.

Right on!

Pushing them into my head to get the drivers closer seems to improve the sound quite a bit, but if that doesn’t work, I guess I see myself getting some better drivers in the future.

Using drivers that aren’t meant for this type of headphone is always gonna be tricky, and is going to be difficult to get good balance. All the drivers made for this type of headphone (so…elleven acoustica, nhoords, magnums, etc.) are specifically tuned to work with the amount of leakage and enclosed ear pad volume that Grado and similar pads provide, taking into consideration there’s no vents on the baffles either, so the pads essentially do all the work. If you use a pair of drivers from entirely different AKG headphones, those drivers will work in a totally different environment than the one they’re designed for. The cause of brightness, sharpness and I assume lack of bottom end is the fact that the enclosed earpad volume is much larger with these big G-cushion pads than it would be on the original AKG headphones, with more leakage as well, since these pads are very leaky. Obviously the best solution would be to get better drivers, but if you can’t, I’d get the L cusion pads, or even the basic flat pads. Putting filters in front of the drivers to tune down the highs CAN work, but not to an extreme level. Flat grado pads will put the drivers much closer to your ears, and the fact that their foam covers the driver entirely will provide some high frequency reduction too.


You may want to review the Grado threads for the ‘tape mod’ to the cushions to improve bass – @pennstac is an advocate.


Thanks for the suggestions. I think I’m gonna try the different pads next.

I actually just popped out the drivers in a different pair of broken headphones I had (AKG K142HD) and they’re working much better!

Using that driver with foam in front of it is actually quite enjoyable. Not a ton of bass, but more than the previous drivers ever got, and everything seems to be very well controlled.

I will keep this thread updated with what I try and what happens. This has been a very enjoyable project so far, so I thank you for putting so much work into the design. It actually required a minimal amount of massaging to print on FDM, and for the level of jank I’ve caused, it seems to have turned out great so far!

I shall check this out. Thank you!


Quick (not to quick) update on my LTA V1 build so far…

I’d love to get some of the recommended drivers to try out, but it’s going to be a while until I’m able to pick them up. So I’ve been using this time to play around with some drivers from parts donor headphones to see if I can get something worth while that way.

Different drivers I’ve tried:

  1. AKG Pro K511 Drivers (40mm): Harsh treble, hardly any low-end. The donor headphones were closed back and not that good to begin with so even though this was a good starting point, it wasn’t a necessarily good sound regardless of the amount of back/front damping I tried.

  2. AKG K142HD Drivers (30mm): BIG improvement! The headphones were still more treble focused but it didn’t have nearly as much of the harsh sharp quality that the last drivers had. Adding polyfill to the rear baffle helped bring the harshness down even more. Honestly, for acoustic recordings with piano and guitar etc… these were very enjoyable, but much less so with electronic music.

  3. Audio Technica ATH Pro500Mk2 Drivers (53mm): after trying the last set of AKG drivers I was very excited to see what a much larger high quality driver would do to the sound. Needless to say, they are now quite a bit more bassy, but not as full sounding as I was hoping they would be. Also, despite all the extra bass, there seems to be a severe sub bass roll-off, making them provide a good initial first impression, then falling apart in a song like “Savant on Mushrooms” by Infected Mushroom. (my go to test for subbass). I’d say these drivers were more of a sidestep than an upgrade from the last AKG drivers. That said, these came out of a closed back can as well, so that probably has something to do with it. Timbre also seems to have a very plastic tinge, but that’s been common between all the drivers so far so that might be due to the earcup pieces.


  1. I’m going to be printing out solid outer grill pieces in order to make a closed back version of the V1. Part of me thinks that this would help get the most out of the 53mm AT Drivers, but the other part of me is concerned about the open Grado style earpads negating any rear baffel sealing that I can do.

  2. More experimentation with Earpads! A couple suggestions on here so far have had to do with earpads, so I’m probably going to look into other Grado style earpads as well as the tape mod. Though I’ve tried the tape mod already and it hadn’t made a noticeable difference to me, I feel like I didn’t do quite a good enough job.

  3. I’m planning on getting some proper drivers that the V1 was actually designed around. Like I said earlier, it will be a bit before I can spring for a pair, but I still want to eventually.

  4. I’d like to experiment with different materials. The current build is done in PLA, but I can also try PETG, both vanilla and carbon fiber reinforced.

  5. There is a headphone store relatively near me that sells Grado among other brands. I’m going to pay them a visit to compare my V1 build to a few Grado headphones.

  6. Eventually, I’m going to try the V2. My brother and I have already gone through the files and started the process of making them more FDM printer friendly.

  7. Tighter head band.


With everything said thus far, I’ve gotten my set to the point where I legitimately think the technical ability is on par with something like a sennheiser HD559. I believe the problems I’m seeing stem from the timbre and frequency response characteristics brought upon by using drivers from a closed back headphone in an open back.

Then again, I don’t think I’ve spent enough time with them to fully evaluate their performance on a deep enough level.

Still, I’m having a blast trying different things and learning along the way. Every time I make a change, it’s almost like getting a new pair of headphones and including materials and purchased parts, I’ve probably spent less than $20 on the project so far.

I’ll continue to update this thread with my findings and any questions I might have.


If you want good cheap drivers that work well in this style of headphone, try to get your hands on a used pair of Sennheiser PX100’s or 200’s, I didn’t try them personally, but I know some people achieved good results with their drivers and with very inert cups. The plasticky timbre you’re hearing is most likely caused by PLA plastic, as it’s never gonna lead to very inert parts, that’s where the reinforced PA’s come in with a huge advantage, although at a much higher price. You could probably reduce some of the effects by applying a layer or two of dynamat onto the walls of the rear acoustic chamber, and then put some felt over it additionally, just be careful with how much stuff you use because it will obviously decrease the total volume and the diameter of the chamber in the process.

That’s the idea, and it’s kinda addictive, isn’t it? :wink: Especially once you get into using higher end parts and materials and figure out you can build something that sounds very, very good, but you can still play with it and end up with exactly what you like, or change it whenever you feel like it.


Just an update, in case anyone is interested in headphone parts for a DIY project regarding the V1 and V2 headphones, or finished builds, I will be making a bulk order for part production some time this week to build a few headphone units, so if you’d like to get some or all headphone parts (especially CNC machined or carbon fiber reinforced plastic ones), send me a PM and I can add extra parts to my order for you. Trying to drop the cost per unit as much as possible, so the more people get on board and more parts I’ll order, the better.

those are some nice Borealis 800’s