First, know your instruments
To design natural-sounding loudspeakers, the designer has to have an ability to recall from memory, on command, the essence of the sound of musical instruments, as heard live.
It's obviously impractical to have an orchestra on stand-by for live vs. reproduced comparisons, but confidence in the abilities of a speaker design can be deduced another way — by listening to it reproducing human voice which to the trained listener is devastatingly revealing of the limitations of conventional loudspeakers. Harbeth's speech-based broadcasting background has been invaluable in honing our design skills in reproducing natural sound, and long experience has demonstrated that once voice sounds natural, as it does on a Harbeth, that music must too. But not necessarily the converse, as the emotional connection with reproduced combined with expectation bias can so easily skew truly objective judgement. It's the elimination of colorations from the vital mid and presence bands which places the open, fresh, honest Harbeth sound in an entirely different league.
" Hi-fi listening is a grand illusion. To turn the physical loudspeakers into a curtain of sound wider, taller and deeper than the cabinets and to conjure performers on command to your home, the sonic contribution of the drive units has to absolutely precisely blended."
Alan Shaw, MD and designer of Harbeth Audio Ltd.