my son in law is a wood worker and I’m thinking of having him make me a headphone rack that we can mount on the wall. thinking about 3 x 3 or 4 x 4 (as in # of headphones it supports).
what do you think the optimal width by height for the space needed to give the headphones the space they need to sit n rest?
22 views but no suggestions on how much space should be made? 
Depends on the headphones. Also I would make sure that you check what you want to put up there so it doesn’t crush foam on certain headbands
Yep some headphones don’t like being suspended just by their headbands and prefer a bit of ear pad support, Senn 6 series are ok being suspended from a single source but if I had high end cans then a dedicated stand or yoga block might be the way forward?.
I also have access to a woodworker and shop and have found it difficult o give him proper dimensions for my ideas. One, because i am constantly changing my mind and 2 because i’m not a woodworker so actually giving him detailed instruction on what i want built has been much more difficult than i expected. Sorry, wish i could be more helpful.
What i do know though is i want different ways of holding different style headphones so as to not crush the foam or headbands. Some need a single pole and some seem to be better with the weight spread across the band. YMMV
Maybe there’s ideas there…
Especially for the headphone wall mounts that won’t crush your headphones. Good idea for woodworking because otherwise holy shit they’re 120$ canadian each what the F$&()(&*("?$. 
lol.
Pegboard or garage rails like Rubbermaid fasttrak work great for hanging headphones imo
fast track doesn’t look all that shick though. 
Nope but it does the job lol. I prefer function over form
well, if it was one or two…yeh…but more, not so much. I’d like my headphone rack to become a statement piece. that SiliverStone is cool…but not for $130 CAD. might have to tell my SiL to get a CnC so he can make me stuff like that outta hardwoods 
this is more like it!
https://www.amazon.ca/WR-HUYUER-Headphone-Portable-Universal-Superglue/dp/B07XT1D261/ref=sr_1_46?keywords=wood+headphone+hook&qid=1569948779&s=gateway&sr=8-46
After seeing that, I’m not going to recommend dowels and pool noodles. Those look really nice. 
Just sharing this for fun, lol.
Curved wooden blocks with foam on top/sides
pics or we don’t know what you’re talking about!