I want to make sure I am orienting my speakers appropriately in my proposed media room.
The image below is my basement. I am still getting the hang of my home designer software so the drawing is crude. The red dot represents a pole that is the "dividing point" between the left and right 1/2s of my already finished basement. The right half is taken over by the kids and their play area. The left half is mine for the theater. The lower left room is unfinished which has the HVAC, boiler, etc.
The ceiling height is 7 feet and the vertical lines on either side of the pole represent a drop in ceiling height to 6.5 feet to accomodate the vent shafts from the blower.
My initial thought was to put a projector screen on the 25'9 wall centered between the pole and the wall with the couches about 12-15 feet back (to allow space behind to get to the HVAC room.) However, given the ceiling height I cannot get a screen larger than the mid 90s inches especially if I have a center channel below the screen. the other negative is that there is no right wall which I think would throw off the acoustics
Place the screen on the 18'6 wall. I could put a 110 inch screen and still accomodate a center channel. The negatives here are that the screen would be about 8 inches off center (there is a small window that I would have to accomodate. Also the theater would wider than it is long. Not sure if that's an issue.
I would put it on the 25.9 wall and use the left side of the room for the theatre area. But it all depends what you are doing with the rest of the basement.
Currently, the right side of the room is my kids play area with toys. The left side right now has my OLD setup with console 50 inch tv and old 5.1 DD set up. It's actually oriented with the TV on the left side of the 25'9" wall. My only concern is the screen size (although I just redid the math and can go up to 100 inches which is respectable) and having an open right wall. My future plans once my kids are older are to turn the other 1/2 of the basement into a pool table/game room.
Depending on what screen type you are going for, I would keep it the same. You could always build a false wall at the front, and make a nice AV cabinet up there. If you truly wanted to separate the room somewhat so the toys don't come over to your theatre side, you could build a half wall. Maybe use some curtains to separate it. All depends on what you are looking to do.