Here is a paragraph excerpted from Laurence Borden's July 2014 review of
the earlier Bache 001 for Dagago. I think it gets to the heart of the
augmented widebander advantage:
"In a typical 3-way speaker, the crossover point
between the midrange and tweeter is typically between 1 and 2 kHz, which
is smack-dab in the region to which our ear is most sensitive. No
matter how well designed a crossover might be, the tweeter and midrange
drivers invariably differ in their dispersion characteristics, transient
response, and distortion characteristics. Making matters worse, the
crossover often introduces phase shifts. Although these differences are
often not recognized per se (except in especially poor implementations),
they become apparent when they are absent, as they are in a speaker
based on a wideband driver. As implemented in the Bache Audio speakers,
the Tangband covers the range from about 100 Hz to about 10,000, or
almost seven octaves. Not surprisingly, they are superbly coherent. As a
result, music has a wholeness — or oneness, if you prefer — that makes
it seem more lifelike. One has a sense of being more relaxed while
listening, a trait I find very desirable in a speaker. Not surprisingly,
instruments that span many octaves — like the piano — are especially
well served, yet all instruments benefit".
Here's the link to the full review:
https://www.dagogo.com/bache-audio-001-loudspeaker-review