Welcome Stew,
I'm not sure I understand the configuration of your wall and ceiling. At first you say the ceiling is angled and then you say the wall is angled.
But regardless,
this might be what you need. In the photo, imagine the bracket attached to a vertical wall. In that position, the bracket could be tilted to aim the speaker down toward the listening area. On a 45 degree angled wall or ceiling, simply mount the bracket upside down, and the speaker could be angled properly. However, you should check with the folks at Axiom to be sure I'm not leading you astray.
If that doesn't float your boat, you might find what you need
here.
Let us know what you do, and how it works out, will you?
