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Zu Audio Omen Def Mk.II

Zu Audio Omen Def Mk.II



All new and ready to set your pants on fire. Omen Def Mk.II further defines its position as the price-to-performance world-beater, do everything well, high fidelity loudspeaker.

Omen Def is recognized as a rock-solid performer and amazing for the money. It vividly and naturally recreates recordings and has a uncanny ability to compliment and work with the acoustics and architecture of most any room. Its also easy to drive and mates well with nearly all amplifiers. And now with easy bolt-on and plug-and-play upgrades, most notably the tweeter, the sky’s the limit and you can get there at your own pace. That’s right, Omen Def Mk.II (besides being amazing in its least expensive form and not just a little better than its predecessor) allows easy user changes and updates—tweeter, high-pass network, cable harness (futures), full-range drivers (these too will get better one day), the addition of optional plinths… all can be done in your own home with simple bolt-on style builds—no soldering, no surgery, no mistakes, and no nonsense.


Here’s just a few of the powers we’ve blessed Omen Def Mk.II with:

  • Deeper sense of ease in all tones, textures, phrasing and dynamic shades.
  • Magnified cogency of intelligence and transient—better pop, shove, hit and attack.
  • Sanctification of the inner detail—bass through treble, not simply treble hyped.
  • Significantly elevated emotional teleportation powers.
  • All while engineered to allow easy DIY upgrade and future update of many aspects of its design, most notably the tweeter. Oh, and by blessed you know we mean, engineered with mad science with clear targets nailed to the door of sonic bliss.

Yes, the price went up, but less than the direct costs of the improvements. Omen Def remains the clear leader in the high value, do everything well, hi-fi speaker category. As you can tell, we’re pretty stoked on our new Omen Def Mk.II, so if you want a speaker that delivers the music and just the music, you’ll want Omen Def—quite simply the biggest sound per dollar (pound, yen or euro) you’ve ever heard.

Enough, What’s Changed

  • Cabinet superstructure.
  • All metal-to-metal fastener systems—no more wood screws, anywhere.
  • Tweeter assembly and mounting technology.
  • High-pass tweeter filter, featuring ClarityCap MR capacitors.
  • Cable harness, featuring Zu Event internal cable.
  • ZuB3 input connection + parallel 5-way binding posts.
  • Machined from billet nameplate.
  • Finish quality.

What Hasn’t Changed

  • Full-range driver, the heart and soul of Omen Def and the source from which everything hinges; Omen Def Mk.II continues to feature our really swell, high-output, nano-sanctified (ZU103ND/G1-16) 10” full-range driver, the very same used in Dominance, Definition Mk.IV and Druid Mk.V, to give real sounding dynamic scale/expression and holistic playback.
  • The architecture, with its Scandinavian inspired lines and subtle tension.

Detail On Changes

Cabinet—less cabinet talk. Yes, she looks nearly the same on the outside (a good thing) but all new and improved on the inside. Cabinet of Omen Def Mk.II is quieter, quicker, more precise… a significant step forward and designed from a comprehensivist position, engineering all system elements to best work within the whole. Webbing, bulkheads and other superstructural elements materially improve transfer of undesirable driver generated mechanical energy from driver housings into the cabinet structure which is then quickly transferred or damped. Cabinet/drivers/interface is designed to work in unison with the superstructure and features constrained layer, stressed member and mixed materials tech to better realize supermodel-level stereophonic performance goals.

Fasteners & Interfaces System—No more wood screws (though the old ones we used were killer). All fastener systems are now metal-to-metal and relay on compression not shear strengths.

Tweeter Driver—Tweeter assembly is all new, including the driver. Designed and made by Eminence, it uses many of the same features found in the top shelf Radain drivers, like toughened aluminum alloy with mylar damping and larger than traditional diaphragm for better dynamic behavior and electroacoustic power transfer. The new driver also uses a dual-wall rear chamber feature to reduce mechanical/acoustic feedback and thus distortion.

Tweeter High-Pass Network—Staying true to comprehensivity and of keeping systems as simple as possible, tweeter and high-pass network were developed to allow the most basic of circuits, a single capacitor. Advantages in designing on a fundamental level usually allows further refinement through better components, and so it is with Omen Def Mk.II—funds that normally get gobbled up in complex solutions to basic problems are freed allowing us to put that cash into ClartiyCap MR capacitors and Zu Event based leads.

Tweeter/Cabinet/Lens Mounting—Compression mounting of the tweeter assembly, using the full thickness of the cabinet as a compressed layer, significantly strengthens the driver baffle area, making what’s typically the weakest area of the cabinet into the strongest. To reach our unusually high and broad compression targets, we engineered the thrust plate for extra large contact area with tweeter driver and cabinet and precision machine the mating surfaces.

Omen Def [Mk.II] Quick Spec’s

Height: 47” [119.5cm] (without footers or optional plinth)
Footprint: 12 x 12” [30.5 x 30.5cm] (without optional plinth)
Weight: 85 pounds [39kg] each (standard, without optional plinth, without optional Zu/Radian-850 tweeter)
Bandwidth: 30 – 25kHz
Efficiency: 101 dB SPL 1W, 1m
Impedance: 8 ohm
Power Amp Range: 2 – 400 watt
Made In Ogden, Utah—U.S.A.

What’s With The Name

Omen Def feature the exact same full-range drivers used in Definition, uses the same dual full-range Definition driver array, thus the Def, short for Definition. Omen because it’s all about maximum sound for the money, with minimum stylistic extravagance. Whatever it’s called the result is classic Zu—clean, simple aesthetics, attractive proportions and sound quality that’ll blow your socks off.

Summary Of Spiel

We introduced our new super-duper, high-output, nano-sanctified 10” full-range driver (the same used in Dominance, Definition Mk.IV and Druid Mk.V) in the Omen Def a few years back, revision Mk.I-B. This is still our state-of-the-art full-range driver. We did this to give Omen Def increased dynamic shove and expression, putting it very near the efficiency and dynamics of Definition. The improvements from the new full-range driver were significant and made for a loudspeaker that could energize any living room with the dynamics and scale of a rock concert yet still reveal the tiny nuances of an intimate performance. Omen Def does all this without “hi-fi” artifice and needs only a handful of watts to prove it.

Omen Def is conceived and create on our Definition platform, but with our entry-level “Omen” production scale, schedule and price values. It’s a speaker that can go toe to toe with many of the best loudspeakers in the world, is happy with the vast majority of amps, looks sweet, is built to last a lifetime, and all at a price that most working music heads can afford.

Omen Def is about stuffing the bulk of the performance features of our renowned Definition into a similarly sized loudspeaker but at a greatly reduced cost. Omen Def gives you 80% or more of the Definition’s performance for roughly a quarter of the price. To get there sacrifices in sound are made, mainly in the super-deep bass and upper treble areas as you can hear when Omen Def and Definition are placed side by side. But hey, for the price difference, who’s complaining. And now with the ability to change out the tweeter for the very same as used in Definition… all you need is a pair of our Undertone subs.

Omen Def is suitable for solid-state as well as vacuum tube amplifiers—and able to mix it up with amp’s from budget to high-end, and from flea watt to mega.

Omen Def is the value standard—no apologies and no reservations. Full-bodied, forceful, delicate, sweet and engaging—aggressive when appropriate, restrained and polite when required, and always seductive.

Omen Def over-delivers on performance, much more than all that Zu driver goodness and machined aluminum suggest. Omen Def is a combination of the technologies developed in Zu Definition loudspeaker, combined with the production methodology of Omen—the result is a standardized high-volume loudspeaker that delivers quality, performance, and good looks at a sane price. Omen Def is quite simply one of the most versatile loudspeaker systems out there—its sensitivity and efficiency deceives small amplifiers into thinking they’re power monsters, with resolution of tone and dynamic expression demonstrate clearly the benefits of moving up the amp’ food-chain to more esoteric gear. Omen Def is built to last a lifetime: cabinet material, adhesives, driver assemblies… every component is a high quality part, creating a loudspeaker system to constantly remind you of the greatest gigs you ever attended.

Tech: Omen Def Mk.II Acoustic Technologies

Third generation ZuGriewe electroacoustic loading ZuGriewe is a cabinet / driver / room acoustic impedance architecture. The technology was developed by Ron Griewe and Sean Casey, with its beginnings developed for motorcycle / automotive engine systems for improving power output through pulse and pressure management within an increased bandwidth.

Tech: Zu103ND/G1-16 Full-Range 10” Driver

This is the same driver we developed for and use on our flagship loudspeaker Dominance. The same driver is also being used on the Definition Mk.IV and Druid Mk.V, delivering stunning attack, shove, resolution and bandwidth.

Features include a maximal motor for expanded dynamic contrast and reduced harmonic distortion; a lightweight neutrally-hung voice coil assembly with a paper/Kapton former; a linear inline layup of the inner cone for best resolution of detail; a diamagnetic shorting assembly for dynamic damping of the moving mass when playing at concert levels; nanotech-impregnated paper cones designed to support wide bandwidth; and a machined from billet phase cone with concentric maximal-length sequence diffusion for smooth high frequencies. All this is anchored to a heavy aluminum alloy frame with overbuilt bonded and riveted yoke/magnet/top-plate assembly.

The nano materials and application process reduce weight while increasing strength and propagation velocity without incurring any sacrifices in damping. We lay-up the paper pulp as a core material, and essentially infuse a liquid solid matrix over it. We use nano-processed and nano-engineered materials and key components in the matrix include nanosphere ceramic balloons, nanofiber cristobalite and amorphous fumed silica. Adhesives and binders include melamine, epoxy and nitrocellulose (aircraft dope). Bitting into the paper core is the first lay-up matrix of nanofiber cristobalite and fumed silica. On this you have a stratum of nitrocellulose and nanospheres. Moving past the lighter, stronger, higher velocity cone you have the Eminence made voice-coil assembly with is combination of paper, Kapton, copper windings and proprietary Eminence adhesives. The center “phase” plug is a carry-over from the research and testing we did with Essence, and gives this driver a more linear management of high frequencies and broader dispersion from the directly-coupled-to-voicecoil inner cone. And as dynamic contrast (to-the-max shove and pop) are of primary importance to us, we mated the new nanotech driver with the same super-tweeter assembly used in Definition Mk.III, reworking the high-pass filter a bit to blend smoothly with the high-resolution high-output full-range driver.


Standard wood finishes for Omen Def are top coated by UV protecting premium grade conversion varnish. All finish work is done in Zu’s custom finish shop.

Tips On Getting Great Sound From Omen Def Mk.II

(Download the owner’s manual, lots of good stuff in it.) Omen Def loudspeakers get 600 hours of high-intensity factory burn-in to ensuring they will sound great within just a few days of play.

Make sure you have 1/4” [6mm] or so gap between the bottom of the loudspeakers and the floor. The finger ports are part of the ZuGriewe box loading technology. They are not ports as used in a bass-reflex design (Helmholtz resonators in all their forms) but the finger ports do need to see the acoustic space of the room. Blocking them turns the Omen Def into an interesting but “sealed” design.

In addition the installed ball-end footers (for use with hard surface flooring) Omen Def also ship with spikes to be used to punch through and anchor the speaker through carpets and rugs.

Thanks for your interest in Omen Def—please don’t hesitate to call or email, we love what we do and we are here to help.