I have a similar sized listening area. A bit shorter and smaller at 36'x24'x8 with concrete floor.
I am using Canto Ergo 1002DCs. No sub. The front ported speakers are 20" off the wall and 108 " apart and I sit 96" back from the line connecting their faces. I've done absolutely no acoustic treatment other than moving furniture. All of the surfaces in the area except the floor are broken up by furniture, cabinets, etc. The Ceiling is irregular, too. I've tried with and without carpet and I prefer without. I did take a lot of time adjusting the position of the speakers with the aid of a CD created for that purpose. I really like the sound of my system, so I suggest you set up yours and play with it before you decide what to do next. It's a little weird sitting in the middle of the room, but I pretty much have the space to myself, so who cares how it looks.
Happy listening
I am using Canto Ergo 1002DCs. No sub. The front ported speakers are 20" off the wall and 108 " apart and I sit 96" back from the line connecting their faces. I've done absolutely no acoustic treatment other than moving furniture. All of the surfaces in the area except the floor are broken up by furniture, cabinets, etc. The Ceiling is irregular, too. I've tried with and without carpet and I prefer without. I did take a lot of time adjusting the position of the speakers with the aid of a CD created for that purpose. I really like the sound of my system, so I suggest you set up yours and play with it before you decide what to do next. It's a little weird sitting in the middle of the room, but I pretty much have the space to myself, so who cares how it looks.
Happy listening