Tbooe,
I'm not sure I'd want to slice my comment that fine. A single subwoofer system that is smoothed with the addition of a second sub, EQ and/or room correction will IME usually produce a sense of cleaner mids than it did prior to such smoothing. As to the conditions required at any specific moment to hear that, I honestly can't say that I've paid enough attention to specify. I can say that the effect has always been pretty evident (and pretty quickly evident) in the systems I've adjusted in this fashion.
I'm not sure I'd want to slice my comment that fine. A single subwoofer system that is smoothed with the addition of a second sub, EQ and/or room correction will IME usually produce a sense of cleaner mids than it did prior to such smoothing. As to the conditions required at any specific moment to hear that, I honestly can't say that I've paid enough attention to specify. I can say that the effect has always been pretty evident (and pretty quickly evident) in the systems I've adjusted in this fashion.