I needed a wall mount for some old Bose 101 speakers I wanted to mount in an outdoor entertaining area and wasn't really able to find anything.   These are made for a high, above head level mount and face downward at an angle.

At the time, I didn't have the speakers on-hand (they were a 30 min drive away), so I only designed this with a single screw hole in the bottom, then I drilled the remaining hole where needed.   This may actually work out better if you want to use the design to mount a different brand of similarly sized speaker.

I printed these a while back and mounted - they are working great, but I don't remember what infill I used (I made them fairly dense to be sure they wouldn't break easily).   I printed in black PETG so they'd be strong and handle the outdoor elements well. 

I printed these on their sides on a Prusa MK3S+, no supports needed and everything turned out quite nicely