BOOLEANS!
Nope. I certainly couldn't have done the operation on the cube that I did
for you with the lofter. I must be misunderstanding the problem, because
when I look at my phone, it looks like an opacity map with a little box
behind it for some dark color would make pretty decent holes for the mike
and speaker. I just don't see the need for sides to the holes unless you
actually want to fly through them into the speaker or microphone.
– G