Screen material is made of thick vinyl. It won't be very transparent acoustically. I don't think there will be much to gain by placing panels behind it. Usind standard screen brackets I would guess there might be 1" max between the wall and the screen material. you will need to shim the screen out if you want to use thicker panels. A piece of recycled foam carpet pad might be just as effective as acoustic panels in that location. Recycled foam is made with various density foam bits which absorb different frequencies. High frequency will be reflected by the screen itself. I would NOT recommend using a perforated screen. This will degrade picture brightness. Moire effects will also occur with DLP and LCD projectors. Perf screens are also much more expensive.