Zu Audio Soul Supreme loudspeaker

My lifestyle consultant warned me not to review Zu Audio's Soul Supreme loudspeaker ($4500/pair).

"Why not?" I asked. "They're exciting and super-enjoyable."

"Zu speakers are not mainstream," he explained. "People either love them or hate them. They're for music lovers, not audiophiles."

"That's not true!" I whined like a disappointed child. "They play Nina Simone and Aretha Franklin with spooky soul and natural tone! They play big classical orchestras—especially with trumpets and timpani—with radical ease and full-tilt momentum! And . . . and . . . they project large soundstages! Isn't that what audiophiles like?"

"Herb, I'm telling you, this is not your normal two-drivers-in-a-ported-MDF-box loudspeaker. The Soul Supremes are definitely not mainstream."

"Are they pro-audio?"

He sighed. "No, Herb. They're a unique product designed to perform exactly as Sean Casey"—Zu Audio's owner, founder, and chief engineer—"believes a speaker should perform. He makes no effort to accommodate fickle audiophile fashion. His speakers are designed for people who get what Zu Audio is all about. That's why they're so special."

"Okay. Okay." Pouting slightly, I stomped my little Iron Ranger boot. "But I don't care! I get these speakers, and . . . and they get me."

As Lifestyle Dude shook his head and looked down at his phone, I mumbled, "And they're made in Utah, just like those other big audiophile speakers!"

You tell me: Is a 10.3" full-range driver with a doped fabric surround, nanotech-treated paper cone—its core is infused with what Zu refers to as "nanometer-engineered structural materials"—ceramic magnet, whizzer cone, and sculpted aluminum phase plug, all designed and built by Zu Audio, not mainstream? According to Sean Casey, "Whizzer cones are a pretty cool design feature on most full-range drivers. They are essentially part of the [coil-] former assembly and dramatically improve the power transfer of treble waves, converting the electromechanical motion that is typically damped out by the main cone into acoustic power, and in desirable ways. The machined pole [-piece] in the middle also helps us to get the spray we desire from treble energy: it works with the whizzer profile to act as a horn."

Casey has developed his own Zu-Griewe loading technology for dynamic loudspeakers, inspired by and based on work he did in the mid-1990s on motorcycle mufflers with the late Ron "Ogre" Griewe, when they were both working for ATK Motorcycles. Casey explained, "Zu-Griewe is an acoustic technology originally developed for high-performance internal-combustion-engine exhaust systems, for improving power output through pulse and pressure management. It increases bandwidth while reducing noise and sound-pressure levels over conventional methods. . . . You can model most of it by merging several loudspeaker loading designs—tuned pipes, horn transforms, and Helmholtz resonators."

Each Soul Supreme is a tall, narrow, truncated pyramid, 37.7" high by 12" square at its base, and weighing 70.4 lbs. No damping material is applied to the interior walls of its cabinet. Instead, a slender pyramid of solid foam rises elegantly from the cabinet bottom. Casey: "The foam pyramid is a component of the whole and does not function independent of the rest of the Zu-Griewe model. However, we can simplify the internal pyramid's contribution and say that it provides internal loudspeaker standing-wave control more effectively, and with greater bandwidth tuning, than fiber- and foam-lined walls, as has been the tradition. You just damp particle velocity where velocity is highest and thermal/mechanical conversion is most effective—not near the walls, where velocity is lowest."

The Soul Supreme's tweeter operates from 12 to 20kHz. It's a 113dB/W/m, horn-loaded, Radian compression driver with a 3" aluminum-alloy diaphragm and a 2" throat. It sports a 49oz magnet with a flux density of 16,400 gauss, and it's made in California. Okay, I admit, that may not be very mainstream. The only crossover parts are a voltage divider and a capacitor on the tweeter. But . . .

"How about the Soul Supreme's sensitivity of 97dB/W/m?"

"No, Herb. That is definitely not mainstream."

I began by putting the Zu Audio Soul Supremes in the exact positions that John DeVore had placed his DeVore Fidelity Orangutan O/93s. I figured that because both speakers have high-sensitivity, 10" paper-cone woofers, they'd probably put about the same amount of bass energy into my smallish room. I was right—the Zus sounded good right away. (Zu Audio gives every pair at least 600 hours of break-in before shipping.) Over time, I moved them farther apart, farther out from the front wall, and toed them in less. It took me more than a week to understand how clean the Soul Supremes' bass really was, and how sharply they could focus an aural image. The more I fine-tuned the toe-in, the bigger—especially wider—the soundstage. Tonal character was always good. Bass was lean, fairly deep, and highly detailed. I moved my couch closer than usual and sat in what most would call the nearfield. Set up properly, the Soul Supremes reminded me of electrostatic speakers, but with greater dynamic responsiveness.

Most of my listening, and most of the observations described below, were accomplished using the Soul Supremes with Zu's own Mission Mk.II speaker cables ($369/8' pair), terminated with Neutrik SpeakON connectors at the speaker end. (Don't all speakers feature both Neutriks and five-way binding posts?)

Listening: First Watt J2
I've been a fan of Sunn O)))'s layered, hyperslow, percussionless drone and drift since I bought Altar (2006), their collaboration with Japanese doom band Boris (LP, Southern Lord 62). Sunn O)))'s music is always a full-on mind shifter and DNA-changer. Forget rhythm and melody—imagine a tautly measured, very loud, almost creeping sonic unfolding. Imagine massive, physical clouds of bass and synth energy. Like my beloved Melvins, Sunn O))) subverts the mindless, ego-driven drum-and-guitar displays of mainstream metal bands by substituting a focused engagement with the contemplative listener. A Sunn O))) song is about inner worlds, meditation, and mood swings, precipitated by roomfuls of morphing energy. Like most of the other music I like, it is a form of church. Add songs written and sung by Scott Walker, as on Walker and Sunn O)))'s Soused (LP, 4AD 73428), and "The most intimate personal choices . . . central to your dignity will be sung" (from "Lullaby").

Listening to Walker sing "Lullaby" through the Soul Supremes and the Nelson Pass-designed First Watt J2, a 25Wpc JFET amplifier ($4000, review in process), was mostly scary, but I survived. The Soul Supremes played Sunn O))) extremely loud (100dB+), quite smoothly, and with a fatigue-free joy that was definitely not mainstream. They let the Moog, guitars, and Walker's haunting voice walk me safely through a fearsome black abyss. Droning bass had a feeling of righteous splendor. It was clean and forceful, but a touch leaner than I expected. The Soul Supremes handled every synth expression with ease and exceptional clarity. "Lullaby" felt as if I, Walker, and maybe David Lynch were all trapped in some endless steel tank with no light. When I picked up the tonearm at the end of the track, it felt as if the music were still reverberating and we were all still in that dark tank, Walker and Lynch standing right behind me. The Zu Soul Supremes were made for this powerfully lamentative music, and the First Watt J2 was born to drive them.

The musical textures of Miles Davis's In a Silent Way (LP, Columbia CS 9875) were succinctly described: Davis's trumpet was realistically toned and nearly full scaled. The title track just rolled by and through my consciousness in a way that made me stop and think, Wow—like a shark slinking though an open sea. The Soul Supremes, perhaps more than any loudspeaker in my recent memory, let Davis and his hyper-talented crew play together with an expressive wholeness that I can describe only as "channeling the Big Force." Whether you're an "accuracy" freak or an old-school music lover, I dare you to find a combo of amp and speaker that will play your recordings more truthfully or enjoyably at anywhere near this price.

Listening: Line Magnetic LM-518IA
The single-ended 845 triode tubes in my reference integrated amplifier, the Line Magnetic LM-518IA (22Wpc into 8 ohms, $4400), grasped the Zu Soul Supremes with a little less authority but a little more gentle finesse than did the JFETs in the single-ended First Watt J2. Weight and body were diminished, but through the LM-518's 16-ohm taps, microtextures became more vivid and noticeable, music more breathy and sparklingly vibrant.

Zu Audio
3350 S 1500 W
Ogden, UT 84401
(800) 516-8925

Odin 412's picture

Great review! I heard these speakers at THE Show Newport and I loved them. I went back several times to listen to more music. These are indeed speakers for music lovers - and that's what I like about them. An additional bonus is that the good folks from Zu always play really good and interesting music and not the usual boring 'audiophile' classical/jazz tracks.

crenca's picture

As an onlooker (I have never heard a Zu speaker myself - looking forward to it however) I have noticed more debate online about "the Zu sound" than is usual around a loudspeaker. These measurements go some way in explaining this. The Zu speakers strike me as the equivalent of a high performance British sports car - idiosyncratic, willing to do things their own way, yet just as competitive on the race track as the more mainstream cars...

chronoglide's picture

Terrific choice of music here Herb ... unexpected and most welcome.
I have been a little bored with the "audiophile safe" music at various shows I have attended. I miss the more daring and adventurous music which we all know exists.

Sunn 0))) -- while not to everyone's taste -- is crafted with as much refinement and mastering care as any audiophile record. Been a Sunn 0))) fan for many years and always thought this band would be a terrific choice, and it was so refreshing to finally see this being used. To future reviewers, please consider using more "out of the comfort zone" records in listening sessions alongside the classics ('Kind of Blue' etc).

If you want to "live dangerously", an even darker and deeper track than Sunn 0))) is the CD "The Place Where The Black Star Hangs" by Lustmord from 1995 (reissued on by Soleilmoon, no vinyl) - track 4 in particular which is 24 mins of the deepest, most layered and intricately textured piece of audio I know of. This will test ANY system.
Thanks for the great choice of music.

Herb Reichert's picture

Thank you for reading my stories . . . I am glad you like SunnO))) and just now I went to buy "Place Where the Darkstar Hangs" but for today it was a little too rich for current situation but I did bid on (and win!) "Purifying Fire" to get a taste of this interesting UK band and Williamson's art - thank you for putting me on to Lustmord !!! peace and crickets

jporter's picture

I think Scott Walker's music is so unique and he has an amazing voice. It seems like everyone at the audiophile shows likes playing Dean Martin. Scott is an infinitely better choice..."It's Raining Today" off of Scott 3 is perfect for testing a systems vocal reproduction. Another great one is "Farmer in the City" off of Tilt. Thanks Herb.

2marco's picture

Thankyou Herb for great review; regarding comparison to another speaker you reviewed last year (in the same off mainstream category )...... What about Zu Supreme vs Tekton Audio Enzo xl?

bijaya's picture

great reviews... not only for this speaker, but all of them which appeared in your list.. very very informative and descriptive.. just love them.. would like to know if any review had bn done on Bose 601 series iv floor-standing speakers.. i hv bn using these speakers since last couple of years with ONKYO A-9050 and 31+31 band graphic equalizer of PHONIC.. sound is good, but want to know if any improvement is possible..!!
thank u all and thank u stereophile.. keep it up.. love u..!!

Dr.Kamiya's picture

Paul Barton agrees with that idea, except he prefers fiberglass instead of foam. Makes a lot of sense too. The point of damping material is to get rid of excess energy going through the speaker, and that wave of energy is travelling mostly down the middle of the enclosure, not toward the walls.

alizaibkhan4's picture

Hey Herb

Great review! i heard these speakers at my friends place and i must say they sound amazing. However, would they be great party speakers? I throw parties every now and then and i am really looking for speakers with rich sound.

Thanks. Keep doing great work.


klosterman's picture

Has Stereophile relaxed their policy? Hopefully they have. I appreciate the 'support the dealers' spirit but there's so many direct to consumer firms, Salk, van Alstine, etc. They arguably need just as much or more visibility, sans dealer network. I think it's fantastic Zu was reviewed, and a cover pic no less.

John Atkinson's picture
Scott.Weinberg wrote:
Has Stereophile relaxed their policy? Hopefully they have. I appreciate the 'support the dealers' spirit but there's so many direct to consumer firms...

The "5 Dealer Rule" applies to products that are distributed through normal retail channels, but we have always reviewed products that are sold direct. For more info, see www.stereophile.com/asweseeit/307awsi/index.html.

John Atkinson
Editor, Stereophile

klosterman's picture

Thanks John for the clarification / reminder. Long time subscriber, big fan btw.

jdjaye's picture

Hi Herb-

Great review of he ZU Soul Supremes - I've had mine for about 3 years and love them!

Can you recommend an Integrated Amp for about $3k to drive the Zus?
Most of your enthusiastic subsequent Amp reviews are in a higher price range...

Thanks and Regards....

woodford's picture

I have an icon audio st40 tube integrated. It’s available from music direct, and I think would be a great match with the zus. Mind, I have not heard this combo, but MD has a 30 day guarantee, and the amp is not dissimilar to PrimaLuna or line magnetic amps.

klosterman's picture

I can tell you what I rotate on my Zu: Eastern Electric MiniMax (tube) & Sony TA-A1ES (ss). Both well under $3k. Both tasty & smooth. Really smooth.

Thomas Collins's picture

How do you quantify or qualify that characterization? What do they sound like? Do they impart some kind of sonic signature to the music that wasn't already there?