For a surround setup you do not want the seating to be placed against the rear wall. In 13x11 room that would probably be the case, so I second the recommendation for removing the wall and expanding the room. You should have enough space behind your seating to place surround speakers behind you. The bed layer is the most important. Check the Dolby ATMOS specifications for recommended speaker layout and angles. If you are renovating the room, try and run conduit for all wire runs inside the walls and ceiling. That makes future upgrades much easier. Figure out your seating location and plan where ATMOS speakers should go, even if you do not initially plan to install them. Get the wiring in place now while renovating and if you want to add ATMOS later then the hard part is done and you just need to install the speakers. If doing this yourself, make sure to use fire-rated speaker cable for in-wall runs. (CL2 or CL3 ratings for residential use.)
