Warnerwh...I understand your point of view. But consider that if you use the "Feedback Destroyer" to do the cuts the bandwidth can be 1/60 octave, and you wouldn't have to worry about affecting adjacent frequencies.
I am using maximum cut around 60 Hz for my rear speakers that are mounted in alcoves. It's the alcoves which seem to function as a resonant external part of the speaker enclosure..ie: the 60 Hz hump is not caused by the room at large. As such, I am correcting response of the speaker itself, so I don't get into the direct vs reflected sound issue. Whatever...it works.