Asymmetry Bad

Just upgraded my speakers to their next generation, which are slightly taller. With the previous pair I had noticed there seemed to be a modest downward angle left-to-right in the soundstage, instruments and voices perhaps a bit more pronounced and "clearer" on the right and the sense of ambience perhaps a bit more prevalent on the right, but it was very easy to assimilate into the listening experience and was seldom notable. Messing with the balance just made the left louder, but not really equivalent to the right.

With the new speakers, I quickly noticed a relative absence of ambience, echo, space, etc. on the left. The disparity was remarkable and distracting. While my room treatment is symmetric throughout, I had two racks of stereo gear in the front left corner that I thought might be causing the problem. I reluctantly moved the equipment off to the right and a bit behind the listening position (a multi-day task if you include ordering and replacing cables, tubing for the tonearm air pump, and more room treatment to fill now empty spaces), and voila! The sound of the hall is no longer just on the right and the soundstage is level.  PITA but worth it