Interesting Serge. I have liked and loathed speakers of every type and come to the conclusion it is about good engineering rather than type.
The most disappointing speakers I ever auditioned, given their reputation, were Spendor BC1s. They sounded delightful on speech and simple music but were pathetic on Mahler (which I listen to a lot).
I have heard screechy horns and mellow ones, and so forth.
It is difficult to measure horns in a conventional way because of the inevitable wide spacing of the drivers. Certainly waterfall plots from horns and panels that I have seen all look hideous compared to well engineered normal drivers.
My direct driver speakers probably are less coloured than the horns though not enough for the horns not to be played.
