(What a terrible title...) I'm working on putting together a versatile music+theater+gaming 5.1 (possibly 6.1) set of speakers for a 15x21' room. There will be two cheap as hell, weak 12" subs (because I don't care much about bass) to take some of the workload off the other speakers which I'll keep crossed at 80 or 100hz. The fronts will be 6 or 7 feet away from the wall, and the listening position will only be maybe 6 feet away from the fronts, and a similar distance from surrounds and center. Let's assume I have a similar room, scaled down in both dimensions except ceiling, which remains a standard 8'. Both rooms are carpeted and well-treated to reduce reverberations, and the listening position is the same distance from the fronts. For the sake of our hypothetical, let's say both rooms have only fronts set up. With our (impossibly) perfectly treated surfaces, will the perceived volume at the listening position in the small room be greater than in the big room? If so, why? I ask because I'm considering some seriously inefficient speakers in the ELAC UB5 and UF5. (Being used to old 10s and 12s, I'm frankly embarrassed to utter "85 db".) I already have a pair of UB5s and they're adequate for the current listening environment (and the only thing I like new for the money), and the doubling of the array in the UF5s will result in around 3db of increased perceived volume (if I'm remembering the rule correctly). Should the future bigger room size not be a problem assuming I am sitting close enough? I am NOT looking to achieve reference volumes 15' back--if I want to deafen myself, I'll do it with a guitar cab. I'm a modest listener, but I don't want to feel as though I'm listening to a smartphone speaker while sitting in my car.