Hi all, Helping a friends church beef up their sound system. Got them some pretty nice gear and i'm looking for advice for the main speaker positions. for the mains we have 4 Yamaha BR10s in a trapezoid enclosure (10 in woofer with horn - Approximate WxHxD: 14 ¾ in. x 21 in. x 12 ¾ in.). We plan to suspend them from the ceiling horizontally (on their sides) and angle them down. the below picture shows my initial positioning idea. there is no theory or mathmatics involved in this. just a general 'spread' thinking. getting as much coverage of the room as possible. the walls are mostly drywall with various decorations (paintings, etc) and the north most (up) wall is about 45% glass windows. I'm looking for advice on the following: 1. Vertical and Horizontal Mounting Angles of the speakers - We are building mounting hardware that will give us more than enough swivel on both axis. the ceiling height is about 10ft to the drop ceiling. we plan to have them hung at there horizontal pivot point around 10 inches down from the drop ceiling. which should give us plenty up pivot to aim up / down. 2. Should we have the horns in, out or a combination? (i'm thinking on center cluster having the horns out and on the outer set having them in...) my initial positioning idea blank for you to draw on if you like one without the inner measurements so you get a better idea of the rooms actual size. Thanks in advance for your help!