I have a totally different solution to this problem. I too use surround sound incorporated within my stereo system and own a large screen Pioneer Television. My best sound is to remove the TV completely from between the speakers, and I do so by employing rollers on the bottom of the TV, allowing it to be placed against the side wall. In this position there is no negative effect in the stereo imaging, and with a long coaxial connected, the TV produces images from the DSS and DVD in either position (wall or center). Many manufacturers, such as Sound Anchors, can custom manufacturer stands to any requirement you have. This and rollers are a simple and inexpensive solution, and much more effective than trying to remove the imaging obstacle using acoustic treatment.
Solution for TV between speakers?
Like many of you my sound system is in the living room out of necessity. The speakers are well out in the room and the audio rack is set outside the speakers. Unfortunately, there is no place to put the 27" TV except between the speakers. Experimentation has shown next to the wall is the best spot. The stand is a C-stand which has a 5-legged base with a question mark shaped vertical post on which a shelf for the TV is attached. It was selected for its minimal mass and "art deco" look. Being at the point of tuning the room an idea occured to me and I'm curious if anyone else has tried it. The idea is to make a cloth "tube" lined with Sonex that would be wrapped around the TV and stand. This would make a floor length column ~4' high that would hopefully not only deaden any reverberations and reflections from the TV and stand, but also serve as a front wall treatment. Kind of like an oversized tube trap. Ideally it would open flat so it could be hung on the wall when the TV is in use. That way it would serve the secondary purpose of deadening the wall for HT (about 10% of the time). Anyone tried anything like this? Comments?