IMO, no speaker can actually reproduce the tonal range and timbre of an acoustic piano realistically, but some I have heard have come closer than most.
To my ears, the old Apogee Full Range Planar was the best at reproducing piano, other EL/planar speakers such as the Maggie MG-1 and SoundLab are also very good, for a couple of reasons: I believe that not only does the nature of the planar transducer more accurately represent the effect of piano strings and a soundboard, but the dipole design produces a similar reflective environment.
I find the Quad designs pretty good at piano reproduction, but their limited panel size makes them less accurate for piano than the aforementioned larger speakers.
One non-planar speaker that impresses me with it's ability to reproduce piano and other tones with little coloration os the Earo Eight; an active, rear-loaded horn design that I find sounds remarkably similar to a planar speaker (but is much more room tolerant and wife friendly).
To my ears, the old Apogee Full Range Planar was the best at reproducing piano, other EL/planar speakers such as the Maggie MG-1 and SoundLab are also very good, for a couple of reasons: I believe that not only does the nature of the planar transducer more accurately represent the effect of piano strings and a soundboard, but the dipole design produces a similar reflective environment.
I find the Quad designs pretty good at piano reproduction, but their limited panel size makes them less accurate for piano than the aforementioned larger speakers.
One non-planar speaker that impresses me with it's ability to reproduce piano and other tones with little coloration os the Earo Eight; an active, rear-loaded horn design that I find sounds remarkably similar to a planar speaker (but is much more room tolerant and wife friendly).