Anyone listen to Zu Audio's Definition Mk3?

I believe it's resolution at low levels is exemplary, a lot to do with it's famous tone dense presentation, high efficiency and lack of crossover.
Density of tone means that the sound is fully fleshed out from low, late night volume levels, whereas with a lot of more expensive speakers (the Kharma's esp IMHO), the sound only "gels" at reasonably high SPL's. So there is no real need to turn the wick up unless you want to, and music can really be enjoyed at intimate listening levels. Additionally high efficiency and an easy impedance curve means that low watt tube/SET's which excel in the more personal type of sound really find a great synergy with the Def4s (and all other Zu models I believe). Finally, no crossover means no sucking of energy out of the presentation, and with the FRD's covering a broad spectrum of frequencies, this adds to the holistic presentation at low to moderate SPL's.
All of this results in excellent resolution, the 4s being a real leap fwd compared to the 2s. Having heard Pro Acs, B&W's, Magicos and Wilsons etc. over the years, IMHO the Def4s give nothing away in terms of resolution.
But that resolution is portrayed in a different way to most other spkrs, cheap or uber expensive, on the market today.

Thank you, Spirit, that helps. I currently have the Soul Superfly with the new Nano drivers and they need to be cranked up quite a bit before coming alive, and I also feel that flea powered SET's would not be the best option for the Soul. I don't quite understand the technical reason for the dfference to the Def. IV's which you describe but it is certainly good to hear.

Gemini, I can't comment on the Soul, just the Def2s and 4s. I'm not hearing any decrease in liveliness, the extra transparency of the 4s' FRDs is providing even more life at low levels in my system, minimising any remaining veil to the music occasionally apparent with the 2s.
Maybe 213Phil can offer his 2 Cents...

The least "alive" Definition was the original Def2, before the 2010 HO drivers. And still, at modest levels it was comparatively excellent at representing full tonal body and presentation of graceful detail with dynamic contrast. Definition 4, and all the ZU speakers with the nano FRD generally, are as effective as you're likely to hear in being able to present aliveness at low SPLs.

The one caveat is -- *after reasonable break-in.* If you buy them new, especially during cold shipping months, they will not immediately bloom at low SPL, even if the apparent volume is there. But they limber up, and do what you want.

As for the resolution of Def4 compared to "conventional" speakers: I have in the past seen some reviewers compliment Zu speakers, with the one aside that in some words or others, Zu in general does not give you "ultimate resolution."

For older Druids and original Def2, there was some validity to that observation, though I argue reviewers who felt that way were mostly accustomed to intensely *over"-resolved loudspeakers, which is a common trait throughout high-end audio today and for much of the past decade. But in Def4, the combination of the nano-FRD and the Radian 850 supertweeter, I think Zu resolution is as high as you'd practically want, and I say this as a former electrostatic speaker listener, and my headphones are Stax.

A lot of what audiophiles hear as "resolution" is either rising top end, ringing and resonance, and crossover artifacts OR it's simply from recordings that are so inappropriately close-mic'd as to render the recording completely non-representative of how you'd hear the same music performed and heard from even the closest practical listening position.

I have no lingering resolution hunger in my mind's ear, when listening to Def4s with commensurately resolving amplification.

Phil

Phil or anyone else,

Is it a big deal if I put the drivers in the wrong place with my Nanotechs?

I installed a matched pair in each speaker rather than matching the top and bottom drivers. I didn't realize this was wrong until I read the instructions that are on the upgrade kit section of the webpage (instructions didn't come with drivers).

Should I bother pulling two out and swapping them or is it no biggie?