Wide dispersion + high efficiency + detail + coherence in a speaker?

The Zu line of loudspeakers have nearly all of what you are looking for.  I don't believe they have the wide dispersion.

@zuio --

Perhaps some older Tannoy Gold 15" dual concentric drivers would do the trick. Simon Mears Audio makes Tannoy Autograph replications with these drive units, refurbished and all, and they provide you a uniform dispersion pattern (much more important than "wide" dispersion, I’d say), true high efficiency (~99dB), detail/insight, coherency in spades, and great dynamics and bass to boot. They’re big and heavy, and will cost you at least or about $20,000/pair, but you asked for it without specifying a retail limit, and I’m giving you an example of speakers that may fit the bill according to your needs. Not least, they’re beautifully made from ground up to original specs.

auxinput,

As I recall the larger Walsh models are somewhat more efficient than the smaller ones, like the microwalsh, and overall they are not any harder to drive than most, perhaps easier. Not high efficiency like Klipsch though for example, for sure. OHM Walsh goes for extended bass in a smaller package so cannot be high efficiency.

Also, regarding coherency, I take that to mean clean integration of all frequencies for the listener. That is what OHM means when they talk about coherency with their Walsh CLS (Coherent Line Source) technology. Imaging and sound stage are different things. OHMS/omnis do those differently for sure, especially imaging. The imaging can be very focused when set up right or not so much otherwise.

Omnis and their ilk will probably never be as pin point focused as say a pair of very high quality monitors can be in practice.

The OHM Walshes go for a live like presentation in regards to sound stage and imaging, not a pinpoint one, which might occur in certain studio recording masters, but hardly ever live in real life or in live recordings.

Spatial Audio X2.

I use subs and new Klipsch Heresy IIIs…subs bought used a few years ago (200 clams each…REL Q150e, Q108 II)…with a well sorted pile of gear behind them, the Heresy IIIs are surprisingly coherant…not beamy, especially for horns (phase plugs do work it would seem), and not too expensive (under 20 thousand bucks…YAY…), but you have to have subs for the anemic bass response. I think "live" sounding is sort of an apt description that could have something to do with efficiency (claimed 99 db), and I mix live shows frequently as a hired Knob Turner so for me live stuff is frequented frequently making me a frequency freak for what I feel is accuracy. Note that as a mixer for live stuff I get to impose my taste on innocent bystanders…hundreds of them at a time…I relish the power and it simply stokes my ego until I spend hours rolling up cables and storing gear…at which time I return to being a regular person.