It's a 12 X 20 ish size with a large opening to an ajacent room front right and an entry and hall in back. I've never known how to define this situation, small room with room to breathe?
I found them too light in the bass but I'm used to a sub. I have a Velodyne DD12. I simply used the crossover in the pre amp at 40 Hz and brought the sub up gently until it blended. Sounds wonderful. I've had various smaller more detailed speakers Merlin, Joseph, Sonus, Coincident, Sivlerline and so on over the years. My first impression of the Harbeth is that it's a keeper at last. Comments above about warmth and coherence are consistent with my experience.
I'm thinking it may be a natural to work with a Rel sub bass system. My understanding is that initially Rel's focus was on just supplying the lowest octave or two for larger speakers. I will be doing some measuring tomorrow with the Velodyne system.
Hope any of this helps, I'm a little blurry after a long day.
Larry,
Seattle