Just want to add that if people are overwhelmed with a large room, it's sometimes easier (and maybe even preferable in sound quality) to section the space and be closer to the speakers. I've heard many setups where I preferred my at home closer, more direct interaction with my speakers to larger, even well treated spaces. Lots can happen for better or worse in that space between your speakers and your ears. There's nothing wrong with being a bit closer if the dispersion works. I've yet to see an 18X40 mixing room.