One thing I’ve noticed in reading his book and even in his posts is that his observations are for multi-seat listening.
Yeah, while I will never have achieved the academic and scientific level of achievement, or renown, of course, that Toole has and deserves, I also come from a motion picture theater background, so I really love his writing and perspective.
In the book, almost everything he has to say about low frequencies and subwoofer placement has to do with optimizing for multiple seating positions. I think this explains a lot about his own choices in home audio. I’m mainly concerned with single-seat listening. My home theater system is good enough for my purposes.
I know it may not sound as relevant, but your fixes are _almost_ always the same. Controlling reverberation time for instance is something hard to do for one spot, without also controlling it in the rest of the room. Adding effective bass traps makes EQ possible.
What Toole gets exactly right, IMHO, is that the concept of room correction is greatly oversold. attempting big corrections in EQ because your sound field sucks doesn’t end up with acceptable solutions for most. Let me explain with a common and specific problem. Let’s say you have a harsh or compressed mid/treble experience in a very live room. Measuring it hyper accurately at your seated position may flatten the curve, but it still won’t sound good. You will control the energy say, between 2kHz and 10 kHz, so it no longer sounds too bright, or too dull, but with long reverb times, all that signal is noise. It’s like watching a movie, where you get the right color and brightness but you can’t tell the actors and scenery apart.
In the bass, with a bad room, the best you can do is clip peaks. Now, that may be a really good improvement, I've seen peaks that were the equivalent of 200x the power output vs. the rest of the system, and clipping them was a major benefit, which EQ can handily do, but trying to EQ these subs into a great response requires a sledgehammer like approach with major amplitude shifts in multiple adjacent bands which, may work for exactly one place and is not all that satisfactory a solution at the end.
Fix your reverberation, and often, the tonal balance fixes itself, and then you are left with very mild, gentle corrections to make. Add bass traps, the peaks flatten themselves, the nulls stop being so severe and again, just a little EQ here and there can give superb experiences.
Hope this helps,
Erik