I just found a new reason to love this hobby a month ago.
Here I was, looking at what headphones to buy, and then @TomislavL comes out of left field with designs for two (working on a third) complete headphones that can be 3d printed. Granted, it took a bit to figure out how to make them play nice with FDM printers, and I still need to get a pair of drivers that actually work well with them, but the V1 is a solid design, even after the jank I had subjected it to.
He has a thread here: Freely accessible modular headphone platform introduction