I wish I could tell you that I'm a sonic guru, but that would be WAY off the mark. However, I'll gladly let you know what I'm thinking. Then, if any of the gurus who peruse this forum see that I'm off the mark, they will hopefully chime in.
For L, C, R, speakers: My intention is to play each 1/3 octave tone, from approx. 80Hz to approx. 800Hz, sequentially through each speaker, taking an SPL measurement for each. The SPL meter will first be located at my primary listening position (in the first row) and pointing at the ceiling. I'll set it for slow response, C-weighting. I'll probably find something tall and thin to double as a tripod for the meter. I'll repeat the whole procedure at my secondary listening position in the first row. Then I'll repeat it two more times for two locations in the second row.
For LS and RS speakers: I'll take measurements from approx. 100Hz to 6.3kHz.
For LR and RR speakers: I'll do nothing. No equalization here.
For the sub: I'll take measurements from 22.4Hz to 80Hz using 1/6 octave bands of pink noise. (Well, probably not... depending on whether I can find a source that will accomplish this.) I have a Bijou eq that provides the ability to adjust within 1/6 octave bands in the sub's THX frequency range. Measurements will only be taken at primary listening position. I'll mess around with playing tones simultaneously through some combo of L,C,R, and sub to ensure a smooth crossover at 80Hz.
I'll average my four measurements for each speaker at each band and attempt to flatten the response. Cuts get preference over boosts. When I am done, I will repeat the procedure for the primary listening position only, to see to what extent corrections in one frequency range have affected other adjacent ranges. I'm hoping that my corrections will not so drastically affect adjacent ranges that I will want to jettison my SPL meter out the window. AudioControl, the makers of the Bijou, advertise a Constant-Q feature that supposedly minimizes this problem.
I haven't decided what I will use as a reference level. Anywhere from 75dB to 90dB. Might depend on what time of day I do this!
I've purchased a few things from ebay, including my projector! That was scary, but everything worked out fine. (So far...)
Thanks for the links! I'm going to check them out.