SA-8 v2 3/4" SD-2-8 1/2" Most 8's you can get away with 3/4" baffle with the rest of the box 1/2". But always remember. If you half-ass your box it will fall apart or sound like crap. And for you haters out there. I put RF HE-2 8's in 1/2" boxes where they lived for 6yrs. with zero problems. So if 1/2 will support HE's, it will support SD-2's.