Dr. Toole - thank you for the excellent summary, insights into and amplification of your previous published remarks. It all makes perfect sense to me, and it is as definitive as it gets.
EQ in the bass typically results, as you say, in a huge payoff, and it seems to work noticeably "better" than no EQ even in systems constrained to a single subwoofer or no subwoofers. But, there is no question in my mind that multiple subs along with EQ are potentially better still.
Full range EQ is much more controversial, as you have highlighted. I do not question that it is, as you say, not necessary above about 500 Hz with the right, properly engineered speakers in a typical room. I agree, full range EQ is no panacea. Still, with less than ideal speakers, there may be some upside in applying it as a "band aid" in some cases, in my experience. That might have been the case to some extent in Olive's testing using the B&Ws. It may not achieve the higher perfection that better speakers might in a better room. But, I admit to being a pragmatist in my own imperfect system. I might be willing to accept a perceived improvement to a given system and room, even if not to the ultimate.
I do use the comparatively inexpensive "upgrade" of full range DSP EQ with very satisfactory results, a net improvement in my subjective opinion. Used properly and with care, the balance of upsides vs. downsides may favor its use from a personal preference standpoint in many cases, again in my experience. So, it might, as I see it, be worthy of some experimentation by the listener in some circumstances.
