Generally you will need to treat all the front wall (for HT experience) with 1" (at least) thick insulation material specially if you have a big screen in a faux wall.
REW is an excellent program to tell you how far (or close) you are from good sound. Learn how to use it, use it then come with a problem that we can discuss.
It is possible (easier) to have near identical sound in a row of seats using at least 2 identical subs (depending on your room...), but not even thinkable to have same sound qualities everywhere in the room, and anyway, you don't need that.
