This Omega style headphone stand was designed to hold two pairs of headphones rather than one like the ones currently available on the market. It was drawn in Autodesk Inventor Professional - Student Version. Should fit most headphones.
For some reason Inventor exported the STL 10X smaller than actual size, so before you print, scale the model up by 10. I may get around to fixing that later if I get bored. STL should be fixed as of 6:08PM 10/22/2015