I've done an experiment in moving some furniture around and in trying to see if there can be an improvement in the ETC graph.
1st ETC measurement. Using the center channel (set as small) with sub and Audyssey switched ON, the following is the ETC graph with the existing furniture as is in the room.
The 1st troublesome reflection point for the center channel is very close the speaker - about a foot away. I thought it could be the coffee table so moved it and re-measured.
2nd ETC measurement. Same as the 1st, but with the coffee table removed.
Think I'm going in the right direction here. There was a change in the response of the ETC in the first two milliseconds. The ETC graph for the center channel is now much better and the next troublesome reflection is just over 2' away. Might try the string technique to identify where this reflection point is.
Maranatz NR1504, Oppo BPD-93, MTV 7000D, LG LW6500, aTV, WDTV Live, Harmony 650 remote, KEF E301, MiniDSP(2x4), Rythmik F12G