Originally Posted by CaptainChunk
I'm using a BenQ MH530FHD that is 13', screen to lens. Seating position is 10' from the screen.
My JBL Studio 590 fronts are too big to fit behind the screen so they are on the side of the screen. The JBL Studio 520c center will go behind the screen. You can see the room layout in this image.
OK...the MH530FHD has the lumen horses to provide an excellent image on the 0.7 gain spandex ....26 fl @ 13' throw. However if the current Screen is set against the Wall, the fact that the 520c will require at minimum that the AT Screen be situated at minimum 9" off the screen wall. Fortunately the MH530FHD has enough zoom capability to allow you to maintain the original PJ position.
The JBLs come in at just a whisker under 13" wide, and 16.25" deep, so including the slight amount of necessary toe-in and wall stand off (sides and rear) their faces would be / should be approx. 20" minimum off the rear wall and 16" to the inside.
That leaves us with an available 9' and even with any added width for a Frame (2"each side) your 120" screen size can be maintained. (104"x 59" image...108" x 63" Frame)
Due to the disparity between the depth of the R & L 590s and the 520c, and the available set Throw distance, your Screen design can only be along the lines of a "H" or "Goal Post" type assembly, supported at Top and Bottom by 2 x 4s attached to Ceiling and Floor. (...if a 120" screen size is to be maintained.
For the Screen Support Frame you would need:
2 - 2x4x10' Top & Bottom Plates..."hand picked Kiln-Dried select Pine" " for having no twists or bows.
4 - 1x4x10' Clear Poplar Boards for the vertical and horizontal braces
1 - 1x4x8' Clear Poplar Board for Inter-spaced short Verticals
The Screen Frame itself is a simple, Flat Frame built of 1x3's using a perimeter of 1/2" quarter Round as a Material stand-off. Minimal Interior Supports would be required since the Screen could be attached all around the Perimeter Frame Work with Finish Nails.
3 - 1x3x10' Clear Poplar Boards
2 - 1x3x 8' Clear Poplar Boards
This should be a good start for you.