I'm having trouble with the QS8's. It turns out there aren't any studs in the ceiling where I am trying to hang them (using the Full Metal Ceiling Bracket from Axiom).

I tried to hang one of the QS8's regardless, to see if it would hold. It didn't feel secure, and wiggling the speaker caused it to come out of the ceiling.

The room is kind of awkward, and ceiling mounting is my only option. I can't hang them on the wall or put them on stands.

Does anyone have any advice as to how I can securely hang the QS8's? I'll take some pictures of the space and post them here shortly to give you all a better idea of what I'm trying to work with.

What I'd do in your case is attach a piece of wood (1" thick, edges rounded off with a router, and painted to match the ceiling) across two studs/joists in your ceiling so that it intersects your desired mounting location. Do this for each mounting location and then attach the brackets to the wood.

EDIT: After seeing your pictures, it seems you wouldn't even have to route the edges. Just cut the wood to fit between the rear wall and the existing beam. Depending on where the joists are, the wood may need to be rather wide.

Just curious why you can't mount to a wall position, looking at the pics there should be studs close to the locations where the wires are coming out?

He's trying to utilize the Full Metal Ceiling Brackets?

Two words.... Toggle bolts!

I've used them for v2.0 and v3.0 of my theater, and they work great!

No studs(joists) in the ceiling? what's holding the floor and the drywall up? did you use a stud finder?

Use this and a sheet of wood, glue wood to wall screw speakers to the wood, it may work. It can hold up to 50lbs

Could you find a smaller pic, please?

Alright, if you really need a stud I guess I can fly up to Boston this weekend. But we'll still have to find a solid place on your wall to hang the speakers.