I loved the design of Skxc headphone hanger. Sadly it wasn't compatible with my Ikea desk, so I've adapted the clamp.

The headphone support width is 38mm, which works great for the ATH-M50x.

If needed, print a small 43x50x1mm flexible square to help with grip. 

Disclaimer: Provided Gcodes files are stock exports of PrusaSlicer, use at your own risk.