So what's the Mconfig sw version?
In Mconfig click on "help", then select "About the Meridian Configuration Program..."
Did you also try the rear speaker or only one rear speaker to avoid the fronts?
Does "speaker calibration" also work with Mconfig?
Please answer all open questions beside my questions, thanks.
800v3/218/271/8k.2/5k5s

/5kC/DSP3200/Reviver/
TT-ELP/Graham Slee Revelation/Trinnov Altitude 32/OPPO 205
__Ayon/HB/Shunyata/Miltzow -- power cables,
__Ayon/Jungson/Miltzow --analog, Miltzow-- digital,
__Vortex/WMA ,