I designed these two acoustic wall tiles in F360. They are 21x21cm square and range from 3-3.6cm high. These were inspired by the wood acoustic wall panels/art that I've seen online. These are a smaller form factor and easily printed on a printer with a bed of 220x220 or larger.
I recommend printing these with 3 walls and at least 15% infill. I generally use 6 top and bottom layers, but YMMV.
Changing infill density should also change sound absorption/reflection.
.step files provided. You can slice these in a slicer or use them to modify the sound boards to whatever configuration you like.