Nick,

Here are some nice links on your question that may help.

http://www.avsforum.com/avs-vb/showthread.php?t=1001579

http://forum.blu-ray.com/showthread.php?t=112329

http://www.seymourav.com/screensfixed.asp

The AVS link suggests to put the speakers in the 16:9 area of your 2:35 screen or perhaps even have a motorized sled of something that moves the main speakers depending on the aspect ratio, among other suggestions.

The Seymour company mentions a AT masking panel called Millibel. When I stumbled upon these links last summer I remember reading that there are affordable AT masking options. So maybe the mains can be placed behind the masking????? Or maybe they are suggesting that you want the masking to be as AT as possible so that there is minimal coloration when the speaker is placed behind the screen in the 16:9 area, but close to the edge of it. If you click on the "store" link on the Seymour website you can see the pricing for the screens and masking is quite reasonable at $1500 to $2000.

I too would like to have a super wide 2:35 screen that goes slightly into my peripheral vision, for that extra immersion into the movie. It seems that the only way that the audio would work with this wide of a screen is with an AT screen. Please keep us informed as to what you end up doing, so that we can see some real-world options.