I've got my 4 Qs8's attached to the boxed in duct work and it works fine. The regular ceiling is 9ft, and I think the boxed in area is about another 10" or so. I found some nice shelf brackets at Menards with gloss black plastic covers to hide the wiring. The Qs8's do not have to be exact in distance as some of the others have stated. They are very forgiving and you can adjust your delay and levels to get the right sound.