For experimental sake just move your listening chair forward until you get the soundstage you are looking for. From that position optimize your speakers forward and back from the front wall. As the speaker move forward the stage should improve but at the expense of bass. Now move back and do the same thing again except move the speakers wider. You’ll finally get to a point that you start to lose the sound stage by just optimizing the placement in your room.
After you’ve reached the best it can be in your room you can start with acoustic enhancements. Simple things like throwing a blanket over your flat screen makes a difference after you’ve optimized the room. There are lots of articles on the interweb about how to determine room interaction but for me without optimization it's hard to determine what acoustic enhancements are actually doing.
Both my ¢s so take it for what it’s worth