The way I see it, the delayed reflections from the room constitute a system that cannot be inverted by manipulating the signal from the speaker.I think I find it useful. No harm done that I can find, and both measureable and audible improvements.
Maybe "room" correction is a poor choice for an identifier.
It's pretty good at "boom" correction in here, though.
Makes the step response look more like the ideal.
Minor things like that. Maybe the results are variable with different sytems and methods of execution.
What's the downside for you?
It may be possible to achieve a true inversion at a single point in space (but that is not guaranteed) but in doing so we make every other point in the room arbitrarily 'weird' - and render the sound at the inverted singularity the sound of the signal in an anechoic chamber - is that what we want?
Such an inversion is more than getting the 'frequency response' flat: as you say, the step response would have to be correct too. It isn't just a graphic equaliser, or even a graphic equaliser with phase control. The true inversion of the room's impulse response (at that single position) may require effectively sending out anti-phase impulses to neutralise delayed reflections at the listening point, then further impulses to neutralise the reflections of those impulses, ad infinitum.
If we couple this mathematically ill-posed problem to that the idea that humans are automatically 'doing the inversion' dynamically as they move around the room, separating the original sound from the 'ambience' effortlessly, it seems to me that the only correct sound is the uncorrected sound. Sure, bass in rooms is thought to be an issue - but I don't seem to have too much problem from that myself. Could this be because I'm listening in comfortable domestic rooms that are carpeted, have furniture, bookshelves etc. in them? Or that I am using sealed boxes, not ports, which helps marry the roll off to the room gain?
The Kii Three approach is to increase the proportion of bass that reaches the listener directly. It is not an attempt to 'correct' the room. As a result, people cannot get enough of the sound. It is a neutral speaker playing into the room unmolested and it sounds magnificent.