A while ago I was wondering if it would be possible to 3D print a great sounding pair of headphones. A search online didn't throw up many other people who have done so, or any literature on how to do it, in particular making them sound great. So it was the perfect project!
After a few mediocre prototypes, a ton of testing to see how different design variables affect the sound and countless design iterations, I've arrived at a design that sounds awesome, looks great and is cheap and easy to build.
The parts should cost you around $35.
If you are interested in reading more about the work I did in creating the design, it's all at Homebrew Headphones. In particular, you can read about how the design variables affect the sound here and about my test setup here.
1 x headband
2 x baffles
2 x covers
I recommend printing them in ABS. Use 5% infill for the headband to give it flexibility, and about 10-20% for the others. The baffles and covers require support, the headband does not.
Print the parts in the orientation shown ion the photo then clean off all the raft/support.