You are a true audiophile hero to actually design your stud pattern around speaker placement. heh heh.

I think a wall plate is 2" and a jigger by 4", so the box is smaller yet than that.

Checking Axiom's specs, the QS4s are 9.5" wide by 6" tall.

Therefore, even if your 2x4 stud was truly 2" wide (which they never are) the QS4 will still cover the box hole nicely with room to spare.

With great power comes Awesome irresponsibility.