Az:

1) in recording studios for movies, do the mixers/engineers use an audio setup that is
a) calibrated by ear to what 'sounds cool' or
b) calibrated by scientific measuring equipment?

2) You want a specific procedure for how to use a SPL meter? Look on either the Avia DVD or Video Essentials. They provide test signals, and very specific procedures for how to use the RS meter to calibrate accurately to those signals. They aren't ambiguous. They don't offer tons of choices.

3) You claim your room is 'perfectly symmetrical', therefore you don't have to worry about L and R speakers having slightly different SPL levels. Hogwash, I say. Due to many of the same variables you call on to put down meters, your speakers, at the same offset setting, may still be off. Why, you ask?

a) no room is perfectly symmetrical. Is it perfectly square (I do mean perfectly).
-- Are there any windows?
-- Where is the door? Is there an identical door in the same spot on each and every wall? Doors have different resonant and reflective qualities than walls.
-- Any wall art, like movie posters? Are they in identical positions on all walls?
-- What about your big screen TV? Do you have an identical set on the other walls?
-- your bass traps: where are they? Are they symmetrical throughout the room?

b) the electrical paths in your equipment may not be exact for each channel. For example, following L & R channels out of a CD player into a preamp, through the gain and maybe A/D and D/A stages, then out again to an amp, to the gain stages of the amp.... this path (especially amp gain) may cause variances in sound level, regardless of room interactions.

If your room and equipment do not meet the above criteria (and many others), it is NOT perfectly symmetrical -- and is therefore subject to variations in SPL, even from identical speakers in identical locations. In short, there is no such thing as a truly, perfectly symmetrical room.

Also, I personally disagree with your choice to go without a center channel. While this is more opinion than anything, I feel that a phantom center requires mains that can image very precisely -- which you may very well have. I do as well -- Martin Logan reQuests. With the center off, I also get a very clear, precise phantom center. BUT, move off center, away from the center point, and that strong localization starts to fade. Since you and your wife each sit off center, a center may give a better central image.
Also, phantom centers (and precise imaging in general) work much better with no obstructions between the two mains. Large objects, like your RPTV can degrade imaging focus. I have a FPTV setup, with nothing but open space between the mains.

On another point from one of your posts, you are incorrect about the design decisions behind Martin Logan center channels, like my Cinema center. The cone woofer and tweeter have absolutely NOTHING to do with trying to provide more vertical dispersion. In fact, the speaker is designed to do exactly the OPPOSITE. Ceiling and floor reflections can muddy dialog. The ML centers are designed to provide a narrow vertical dispersion to limit refelections, while providing wide horizontal dispersion to provide a clear center image across the seating stage.

The woofer and tweeter are there simply because of the size of the electrostatic panels. In very large ML speakers, the panel can recreate most of the sound spectrum on its own, negating the need for phase altering crossover networks. However, the panels in the center channels are too small to provide any kind of bass, or very high end. The woofer and tweeter fill in for these areas, while the static panel provides all midrange sound lending ML clarity to dialog (the most important part of a center).

[This message has been edited by bigmac (edited August 10, 2002).]