The problem comes back to needing to mask off the screen. I can't use curtains since I will be going with an acoustically transparent wall for the screen with the speakers behind it. So I would need to make some rigid panels if I wanted to block off the extra screen height (or width for that matter).
So you don't think that the speakers in the 16:9 area of the screen will be fine? Perhaps also doing width speakers would help. Then you may need to get a new receiver to do this if you don't have one already.
Also, what about making curtains out of speaker black grill material.
