I have a 818.3 to try but I can't get it communicating all functions with the DSP7200.2. Axis, EBA, EBC, Loudness, position don't seem to react.
With 218 these functions work. After pressing store on the app the sound drops off for a second or so and the DSP's play with the new adjustment.
That's not the case with the 818, it plays without interruption and no noticeable sound changing. Bass, treble and balance work fine.

Some Meridian...