Originally Posted by edmove
Okay, mic pointing directly at front stage. I am resting it on the cushion of the theater couch. So right at ideal seated position. Before had it wedged between center seating which gave a slightly elevated position. Other adjustments was setting the treble up to +8 and leaving Bass at +0.
You really don't want to do that (it'll sound unnaturally bright) and don't want a flat reverberant field.
The problem here is that your ears are looking at the direct sound, similar reflections that are coming later, and combining their spectrums with some sort of time-based weighting to determine timbre. They expect some roll-off in the reflections at high frequencies because those are more readily absorbed in natural surroundings and have higher losses with distance (listen to what happens to highway noises as you get away from one - you hear more low frequencies when you get distance and things like trees between it and you).
The microphone is just adding all the reflections together equally (apart from its pickup pattern, which we'll ignore to simplify the discussion).
What option do you recommend for bumping up the HF 2-4 db? Or do I need to do some flattening first at the HF?
Leave the high frequencies alone unless you have room problems you can't address acoustically (speakers in a big room with lots of sliding glass doors, tile floors, etc. A cut helps but doesn't work as well as fixing the problem). Don't make fine grained corrections.
Low frequencies are different. Your ears need a cycle to pickup the tone and are picking up reflections before they're done with a full wave of direct sound. Perception seems to have more to do with the steady state measured response.
You just want to consider what's going on when you want multiple "good" seats, where the interactions of room modes can be radically different (even 6" away) and aim for the best average corrections.