It may not be as easy as print, plug and play, but designer J.C. Karich is proving that you can make a pair of working headphones with nothing but raw materials, a 3D printer, open-source designs and a little gumption. Karich 3D-printed the body of his headphones, which others have done before, but he made his designs with DIY function in mind.
He created the speakers by coiling copper wire around a groove built into the printed casing, which also has a nice little spot on the opposite side to house the magnet.
The jack is 3D-printed as well, with the usual audio connections made by wrapping wire around a delicately printed plug. He wired up a fabric connecter from fabrick.it for the headphones' cord.
The build is impressive, but the best part is that it actually works! While it requires a power amplifier to play music from something like an iPhone, in the creator's own words, "the sound quality is very nice against all expectations". Watch until the end of the video to to decide for yourself. If you're in the mood for a DIY project -- and have access to a 3D printer -- you can get the designs here.