New to this forum and pleading for advice on setting up my home theater. I have a large basement, and an area that I plan to use for a theater - but one side (right side of viewer when facing screen will be open. I have attached a sketch (hope it is viewable) of the dimensions of the room. I am planning to use a 4K projector and multi-component system to project to a screen of 120-135". I also plan to order speakers from DIYSound group to supply the sound, but not sure what I need. I plan to have an ATMOS setup with 2 subs. I need to sound proof the area as best as I can - though with one wall open to the rest of the basement, this will not be ideal. Any suggestions would be very welcome. Thanks in advance.