Show hotel listening conditions are compromising to every piece of gear exhibited, but are especially challenging to loudspeakers. I've heard Zu at 3 shows and while they were more than competitive relative to other speaker exhibitors under the same conditions, the sound available in the peculiar floated construction of hotel buildings was not more than a fraction of what's attainable at home.
Zu has sometimes exhibited with speakers that were not fully broken in, and during the break-in period, there is definitely some peakiness to midrange tones that levels out. That trace of horn-like shout you can hear when brand new, is real and disappears.
MJ mentioned that he thinks the Definition has a more solid-state-friendly impedance curve. While the Def's impedance curve is smoother over frequency range, most solid state amps will sound smoother and more musical into the Druid's 12 ohm load, though they will be down on power while doing so.
The 38Hz bass performance of the Druids is not dependent on proximity to boundary reinforcement. They will do that in the middle of a room. The boundary that counts is the floor, where the gap spacing for the Griewe model is set. On Mk4 Druids, Sean specs a CD jewel case thickness worth of gap. Tiny deviations up or down from that make significant differences. On older Druids, that gap should be about doubled. Narrowing the gap will make the bass drier and tonally less rich. Widening it will soften bass definition and introduce a fatter bottom. Amp characteristics can be countered with some slight tuning.
I agree with Duke that the absence of crossover likely has benefits additional to the ones I've previously cited as being obvious, but in general a crossover speaker sounds regressive after hearing the octave-to-octave consistency of Zu.
Phil
