Hi- I have also asked this of Definitive, but would like to see if anyone knows how the Audyssey MultEQ XT works, or maybe conflicts, with the design of the DT Mythos SSA-50, used in conjunction with a ProSub 800, and 4 additional channels (Surround WIDE and Surround BACK, using ProMonitor 800s). I have read that there is a compatibility challenge when trying to employ the MultEQ XT with this setup.
The issue comes from the virtual surround method used in the SSA-50. To achieve that effect, they cross-feed signal from the left channel to the right speaker and vice-versa. This makes it difficult for MultEQ to measure the speakers individually and create a room correction filter for them. If there is a way to temporarily disconnect this cross-feed signal then you could measure the speakers and save the calibration. After that you would re-connect the crossfeed and have great sound. In fact, these types of virtual surround systems work even better if the in-room speaker response is corrected.