I’m curious what reason you have for wanting an AT screen. Not that they don’t have there uses but just because it’s AT doesn’t mean your overall setup will be better as it really depends on the situation IMO.
You really should determine what screen width you want by experimenting and not just following someone else’s guidelines. If you don’t already have a projector you can shine on the wall to gauge screen size from then the best way I know is to go to a theater and find the seat that gives you the best viewing angle. Pace off the width of the screen and the distance to it from that row and calculate your own screen width to seating distance ratio.
That said there’s only a few ways to reconcile the angles.
Use as wide a screen as you are comfortable with and put the L/R mains as far out as you can and live with it. By my calculation your seating would only be 13’ away from a 105’ wide screen at a 36 degree angle. You may also find you actually prefer to sit closer.
Put only the center speaker behind the AT screen allowing the L/R mains to be positioned farther out. This may also allow some more flexibility in placing the mains to give you the best overall soundstage rather than your screen dictating how your soundstage is set up.
The best way I could figure out was to ditch the idea I had to use an AT screen and go with a standard screen with my speakers under it. Doing this I avoided the risk of morie’ and any possible sonic hit to the high frequencies caused by the AT screen. It also gives me complete placement flexibility for my front 3 speakers so I can have the best possible soundstage.
