Review By Ric Mancuso
The Zu Audio Omen MK.II are not conventional loudspeakers but that’s not surprising considering their heritage. The Utah-based manufacturer has always marched to its own drum and there are a growing number of customers who agree with its design philosophy.
I asked Sean Casey, owner and founder of Zu Audio loudspeakers, “How did you come up with the name for the company?”
“One evening while having a conversation about creating the company with my wife, the name Zu popped into her head,” Casey replied.
It sounded cool, and they came up with a logo and Zu Audio was born. Sean heard members of the industry say never to disclose the origin of the name, fearing it would evoke a perception of fictionalization; something that would somehow undermine the brand’s quality. What’s in a name? Well, Prince did pretty well with his symbol and his brand.
Sean Casey Of Zu Audio
Sean Casey’s background in audio is an interesting one. He and Ray Kimber, both Utah audio heads, were involved in the club scene in Ogden and had a mutual interest in PA systems and sound.
Ray went on to create Kimber Kable. Sean was doing DJ work and dance party gigs in clubs at the age of 16. Sean’s parents, while not huge fans of his musical tastes, were very supportive of his work ethic and passion for his craft.
Sean claimed to be a recalcitrant Mormon.
Along with that endeavor, Sean the motorcycle enthusiast had teamed up with Ron Griewe, motorcycle legend, and inventor. It probably won’t shock people to learn that much of the technology behind Zu Audio loudspeakers is based on a motorcycle muffler.
What Is Zu-Griewe Loudspeaker Technology?
This technology is used in the majority of Zu Audio’s loudspeakers. The concepts can be used in any loudspeaker where there are internal velocity changes. Introduced in Zu’s very first loudspeaker, the Druid, the Zu-Griewe technology is a multi-octave impedance modifying acoustic model that can be applied to any acoustic system with alternating velocities; electro-acoustic, electromechanical, internal combustion engines, and so on.
The concept evolved from the relationship between Ron Griewe, motorcycle legend, and apprentice Sean Casey. Sean says that he was a punk kid and that Ron had mentored him and gave him ideas that would be eventually be incorporated into the Zu Druid loudspeaker.
The original concept is Ron Griewe’s and had a nice bit of engineering insight as he sat inching through Los Angeles traffic one afternoon.
Zu’s first speaker was the Druid in 2001. Sean had been intrigued by the Cerwin Vega folded horn designs along with Klipsch and RCA speakers.
“Speakers you could get through the door,” explained Casey.
You will always notice full, deep, and effortless bass tones emanating from Zu Audio’s designs.
Zu Omen MK.II Loudspeakers
I have always been impressed with the sound of Zu speakers that I’ve heard at audio shows. Sean and his staff exude passion and their room is the best place to hang out. Unlike a lot of other rooms at shows, the Zu room is more about the music than showing off some new product that 1% of the population can afford.
Sean employs a Rupert Neve 5060 (high-end) mixing board in a DJ format driving his favorite amps of the day powering usually two models of Zu speakers.
The demo allows people to pick their favorite LPs to play from the bins of various genres of music that Sean collects. It’s like attending a party. You even get a cool Zu t-shirt.
I had ordered a pair of Zu Audio Soul Supremes to audition a few years ago and was impressed with their sound. Unfortunately, we were in the process of moving back to Oregon from California. I never really had the chance to fully evaluate the speakers.
Having pushed that feeling of intense disappointment out of my head, I was inspired to get another pair of smaller Zu speakers to review in my near-field listening room in our smaller home.
Such a close listening position made me somewhat nervous based on my previous experience listening to Zu speakers in much larger rooms but Sean told that the Omen MK.II work well in a near-field situation.
I originally wanted to review his bookshelf model.
“Nope. I’ll send you the Omen Mk.II’s — you can even put them two feet away from your listening position obtaining great sonic results,” Sean told me with the confidence that he’s known for.
Zu Audio speakers typically receive many votes for best sound at audio shows. Must be a reason? Well, I had to wait a while before getting the speakers. As we all know, 2020 put serious constraints on the supply chain, along with the company having to employ health safety practices for staff workers.
The company like many other audio manufacturers is deluged with backorders. Home audio is thriving because of the lockdown. Folks are investing in home entertainment products, including expensive audiophile gear in lieu of going out to see concerts, dining, and movies because of the pandemic.
The Zu Audio Omen MK.II floorstanding speakers arrived in sturdy cartons and were easy for me to unpack. I walked them out of the box, in which they were tightly wrapped in shrink material. I did not use the supplied spikes and elected to use the Black Ravioli pads instead. They are superior to most spikes on the market.
I set them up using my standard near-field mathematical formula. 3 feet from the back wall with an ear focal distance of an equilateral triangle of seven and one-half feet with a slight toe-in of five degrees. These speakers immediately defined a center image with vocals rock solid in the middle of my space.
Sean says that the best way to set up Zu speakers is to achieve a perfect tonal balance with the music. He says if you get that part right, then everything else will fall into place. I remember the late-Gordon Holt mentioned the same thing years ago regarding speaker set-up.
What Do They Sound Like?
Zu speakers have a reputation of being able to play loud and rock out. I took the opposite tack and played a few classical pieces with a variety of symphonic works, piano concertos, and choral pieces.
I played the CDs at soft to moderate volumes with very satisfying results. This speaker can whisper at you and blow a kiss to your ears. My ears heard all of the spatial cues in the recording with the correct perspectives of soundstage and tonality.
What I noticed first off was the instruments sounded authentically real. Kind of reminiscent of an LS3/5A design. I own a pair of the Falcon LS3/5A monitors and was struck by the similarities of the midrange performance.
I played a Rolling Stones cut off the Sticky Fingers LP using an Audio-Technica entry-level turntable with their moving magnet AT95 cartridge. This fed an ancient Hageman HAPI 2 phono preamp.
I goosed up the volume and had a big boy rock speaker experience. Again, the tonality was spot on. Vocals properly painted across the soundstage with the biting guitar of Mick Taylor throbbing those famous licks.
More than ample bass, but not overly plump. Most of us have been weened away from enjoying life-like bass over the years. Most high-end audio speaker designers focus on transparency and spatial reproduction as the holy grail; unfortunately at the expense and sacrifice of low bass information and tonality. All of these sacrifices create loudspeakers that sound too lean.
Also, perhaps ageing ears and the loss of some HF acuity contributes to designers voicing their speakers with a tilted frequency response. Do you wonder why Klipsch and JBL have experienced a resurgence in the high-end audio speaker category?
I think it’s because people are lusting for a more robust listening experience. Full-bodied, rich and full, and yet delicate at the same time. The Zu Audio Omen MK.II can do the high intensity dance along with the subtle stroke with a velvet glove.
More From Sean Casey
Speaking with Sean about his choice of drivers and how they impact performance, he explained the rationale behind the 10-inch driver; which all Zu Audio loudspeakers utilize in the product line.
He explained that a lot of the pro audio industry uses 10-inch drivers, because of its ability to have a rightness of sound and realism in regard to the fundamental tones. Musicians (Tone-heads) generally prefer 10-inch versus 12-inch speakers. Sean also mentioned that the 10-inch driver approximates the size of the human head.
I’ve never heard that explanation before but it makes sense when you think about it.
It is the one thing that defines Zu speakers; the correctness of tone. I kept hearing instruments and voices in recordings that sounded real. The 10-inch human head not only projects sound, but listens to sound. It makes total sense to me.
All speakers have specific demands in regard to amplification in order to perform properly. While the rest of the components are very important as well, I’ve heard enough amplifiers with Zu Audio speakers at shows to know that system synergy with their products is very important.
I asked Sean Casey for an explanation in regard to what types of amplifiers work the best with his products and he mentioned a number of solid-state and tube amplifiers, including the original NAD 3020 that could sound great.
When I had the Soul Supremes, I remembered that I had used the NAD along with the Jolida FX 10 EL84 tube amplifier with excellent results.
I used three different amplifiers to evaluate the Zu Omen MK.II. I started with a Rogue Audio Pharaoh hybrid class D tube design with close to 400 Watts per channel into 4 Ohms.
The Omen are a 12 ohm load. I fell into the trap of playing them too loudly at first. My ears were ringing. I pulled out my SPL meter and settled on about 85 dB as a good place to start. The speakers are rated at 97 dB (12 ohms) so it doesn’t take a lot of power to achieve loud volume levels
The damping factor is very high with the Rogue. I was ready to call it a day with this amplifier; very tight and full bass, and a soundstage so wide it stretched well beyond the room. The midrange was spot on; imaging was rock solid with vocals locked into the center of the room with excellent depth. The image height was very believable with almost every recording.
Only the Magnepan LRS would slightly best the Omen MK.II’s in this regard. I played an Alison Krauss CD to test for vocal purity; she was eerily present in the room with me and I loved the texture of her voice.
The Manley Labs Mahi tube monoblock amplifiers were an interesting choice; I tried various combinations of feedback, triode, and push-pull settings. I used the Rogue Audio Pharaoh as the preamp. A rather good match as it turns out.
The sonic flavor of the tube amp had a magical quality with the Omen MK.II speakers. The added warmth was undeniable. The bass was a little loose, as I would have suspected, but the overall texture and sense of color was superb.
The NAD 3020 was the last amplifier that I connected; I used 16 gauge lamp cord wire with the Zu Audio Omen MK.II’s. Guess what? It’s one of Sean Casey’s favorite amplifiers. The speakers brought on another magical experience. I ran my CD player directly into its auxiliary input and was not surprised by the soundstage depth and width; the tonal balance was rather rich with the NAD and I can see why a lot of vintage audio fans would love this combination.
I believe that if a loudspeaker is designed correctly, it will check all of the boxes and be both entertaining and musically engaging. The Zu Omen MK.II succeeds in a very significant way on both accounts.
I see parallels with Zu Audio and Klipsch. Sean Casey and Paul Klipsch were basically cut from the same cloth; two designers blessed with ingenuity and a true understanding of what makes music resonate with human beings.
The Zu Audio Omen MK.II floorstanding speakers belong within the rankings of highly praised classics. They remain in the lineup of speakers still in production at the company. How about a classic speaker that is only three years old and as refreshingly new as they come? The Zu Audio Omen MK.II speakers are staying within my reference system and will be used as a benchmark against everything that is to come.
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Tonality Sub–bass (10Hz – 60Hz) Mid–bass (80Hz – 200Hz) Midrange (200Hz – 3,000Hz) High Frequencies (3,000Hz On Up) Attack Decay Inner Resolution Soundscape Width Front Soundscape Width Rear Soundscape Depth Soundscape Extension Into Room Imaging Fit And Finish Self Noise Value For The Money
Type: High-sensitivity floorstanding loudspeaker
Frequency Response: 35Hz to 22kHz
Impedance: 12 Ohms
Dimensions: 36″ x 12″ x 12″ (H x W x D)
Weight: 54 pounds
Price: Starting at $2,349
3350 South 1500 West
Ogden, Utah 84410