Re: Direct Sound, Early Reflections, and Tone
At the SynAudCon EQ07 Worskshop the approach was discussed that is similar to that I used, which is basically:
1. Tune the box (free field within the coverage).
2. Tune the array (free field within the coverage).
3. Tune for the effects of nearby surfaces and early reflections (boundary gain and cancellation, tonal effects, etc.)
4. Tune for the general room acoustics and gain before feedback.
5. Tune for subjective and artistic peferences.
Note that tuning is not limited to equalization, it can include adjusting level, delay, locations, aiming and other factors. Also note that Items 1 and 2 can be performed in advance but the rest require the system to be in in place as it will be used. I'll also often approach Item 5 with separate processing that is more user accessible.
Your comments on the tonal region also seem to relate to the ITDG or Initial Time Delay Gap, the goal of having a period of 10-25ms between the direct sound and first strong reflection. ITDG relates to intimacy for room acoustics but the 10ms lower limits goes back to the same tonal/timbre issues.
You might want to look at EQ the Room? « Synergetic Audio Concepts and http://www.fulcrum-acoustic.com/wordpress/wp-content/uploads/2010/11/Comments-On-Half-Space.pdf. Both of these address reflections affecting the resulting response.
Relating all this back to your comments, I would agree with the free field response being a good starting point with two caveats. One is that you also have to control or eliminate very early reflections, which can typically be best addressed by proper design and application. The other is that it is a starting point and you still address the power response, gain before feedback, air absorption and other room/application related factors as well any subjective preferences.
