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Zu Audio Soul MKII loudspeaker review

  • Lone wolves.  Single-driver speakers and their crossover-free implementations are popular with some audiophiles because of strengths with imaging, soundstage depth, speed and an ability to better communicate tone and texture than their multi-driver brethren. Full-range drivers enjoy higher sensitivity (90+db) too. This opens the front door to a wider range of amplifiers. Without a crossover sitting between amplifier and loudspeaker you can be up and running with just a few (quality) watts; this is where many love affairs with ‘pre-cognitive’ SET amplifiers are ignited.

    However, such single driver designs aren’t free of compromises. Very few things are! They often display shyness with slam – a reluctance to shake their booty and punch the air. 47Labs’ Lens were great in communicating the crystalline acoustic beauty of Kings Of Convenience’s Quiet Is The New Loud but they weren’t as crash hot at reproducing the bigger crunch and drive of Ministry’s Psalm 69. More satisfying results came from more standard two-ways: the ProAc Tablette Reference 8 and ATC SCM 11. If your speaker of choice has more than one driver, it’ll probably also contain a crossover. And that crossover might knock purity and speed. It might also knock tonal/timbral communication. As the ad copy runs on the Zu website: “no matter how you bake ‘em crossovers are tone killers.”


    The Soul MKII’s 10” Nano-tech driver (ZuCX/ND-8 FR) is designed to bridge these two worlds.  Zu Audio mainman Sean Casey wants you to have your cake and eat it.  Yes, it’s the same driver as found in the Union – not an off-the-shelf driver from Eminence, it’s made to Casey’s strict specifications. The FRD stands for full-range driver. ND indicates the (secret sauced) nano technology contained therein.

    There isn’t a crossover here. The amplifier talks straight to the driver. The nano-tech unit runs (as near-as-dammit) full-range – from 45Hz to 12kHz – after which the coaxially configured super-tweeter takes over proceedings – via a simple high-pass filter. Each driver gets 600 hours of factory burn-in time before being fitted to the cabinet and shipped. 99db efficiency – pretty much any good amplifier will have you whistling Dixie (more on which later). Nominal impedance is rated at 8 ohm. Cabinet height is identical to an Ikea Expedit shelving unit.  Mine are a mis-matched pair from B-stock – one Walnut finish is clearly darker than the other.  How much? US$3500 on home soil but Australians see some good news here: the Soul MKII are available for a limited introductory price of AU$2750/pair, shipped.

    Setup. You need to spend time on this. LOTS of time. Small changes in placement, lean and toe-in can solicit dramatic changes in sound. Ensure there’s some daylight between the bottom of the speaker and floor (at least 6mm). The downward firing finger-ports need daylight to ensure the ZuGriewe cabinet loading functions properly. The larger the gap, the more bass you’ll get. I experimented with longer, store-bought bolts to push low frequency slam to the maximum; too much for my room but proof that they’ll play ball in bigger spaces. MUCH bigger spaces.


    If you’re in an apartment, you might find that the supplied spikes are too long. I’d urge the guys at Zu HQ to consider shipping their speakers with super-short spikes to accommodate some of the smaller living spaces that prevail in the UK, Japan and (to an extent) Australia.

    Get overall speaker placement wrong and the Souls will sound dry and scratchy. It took me several weeks of tweaks to optimize all that the Soul MKII can offer: firing across the room, 90cm clearance from rear (long) wall and only 30mm lift from the floor. Canting them back a few degrees also enhances imaging.

    Listening. The Soul’s midrange hits you RIGHT BETWEEN THE EYES. You don’t have to go to it, it comes to you. Vocals are thrust several paces in front of the speaker plane with imaging that makes it a cinch to forget that there’s a two-box illusion going on. Music grabs you by the lapels. “Hey buddy!”. Here is a loudspeaker makes you an offer you cannot refuse. They’re more boisterous than they are polite but there’s an abundance of tonal refinement on tap if your amplifier is up to muster. Let’s just call them ‘present’. Did I mention that you get dynamics that turn on a time? I did? Good.


    The sheer honesty with midrange exposure is far superior to that of the outgoing Magnepan MMG. So too is soundstage width. And depth. Golly. It only took a couple of spins of Morrissey’s Kill Uncle vinyl to peg these three improvements.

    The all-round transparency that the Zus lord over the Maggies highlighted some hitherto undiscovered errors in one of my turntable rigs. They didn’t just shine a torch into the odd corner; they lit up the entire room under full house lights. For better or worse, very few secrets will get past these loudspeakers. I couldn’t say that about the Omen. The Soul MKII a more mature, less naïve design. Their honesty can be brutal. Play a bad recording and it’ll sound terrible, play a good recording and it’ll sound amazing. If you don’t like to hear these differences writ large, the Soul MKII probably isn’t your next speaker.

    The acoustic guitar plucks that usher in the title track on Pink Floyd’s Wish You Were Here arrive beautifully formed: attack, decay, sustain, release.  Decay wings don’t get clipped.  If it’s in the recording – or your hardware – you’ll hear it all. These Zu take you  closer to the (herp-derp) soul of  that which precedes them…


    …and funky town. Turning to David Byrne’s 3 Big Songs EP. The squelchy afro-rhythms of “Big Business” – that are only an heard as undercurrent via the MMG – are given space to dance their way forwards to greater prominence when placed in Zu hands.

    Amplifier choices. The Soul won’t smudge or smear what they are fed. You can tap most the Soul’s inner-glory from just a few watts but – be warned – you won’t get a free lunch by cutting corners. Something like the Miniwatt N3 will get you up and running but it will shave back acoustic mass and shrink the soundstage.

    Here’s the key: these Zus sound best when paired with amplification that’s big on tone. The NAKSA 80 jumped to the job. Red Wine Audio’s Signature 15 / 16 would also be a sound match. Even the natty little Rega Brio-R would go OK here. Go for something a bit softer in the presence region (upper mids).  If you don’t already own a DAC, the Peachtree Nova125 makes for a terrific choice. Mellow Class D implementation + switchable tube buffer = a sound that’s sumptuous and inviting. This Nova iteration might have proven a shade too laid back for the Magnepan MMG but it’s a perfect fit for the already-up-and-at-‘em Soul MKII. No wonder these two manufacturers sometimes do shows together.


    A Weston Acoustics Topaz (AU$1800) push-me-pull-you is where it’s at for majesty and harmonic glory. Here is an amp-speaker pairing that’s ideal for both kick-ass rock n roll and long-fingered elegance with acoustic fare. Make sure you have a room of sufficient size though – both soundstaging and dynamic energy are tremendous when the Soul are paired with Earle Weston’s handmade beauty. Acoustic mass is C-H-U-N-K-Y.

    Dynamism and excitement. It’s tough to sit and listen with music as a background concern. Like all Zu loudspeakers, even at low volumes there’s a party going on. The Ogden-based team have welded the speed and imaging of a single driver sound to the heft and dynamics that’d you’d find in a more mainstream two-way design. They can be polite when the music calls for it…BUT when kicking back with a cup of coffee and some Nick Drake one lazy Sunday, I couldn’t shake the feeling that the Souls were sitting on their hands, just waiting to kick it up several gears with some Zomby or James Holden.


    Soul mining. Paint this mental abstraction: an open cavity exploration of music – one that finds the inner-voice of song, the mouth inside the mouth. Imagine too the saturated tonal colours of an oil painting where detail is conveyed with tip-of-the-paintbrush finesse. Pour in the thrill of a motorbike’s corner lean. That’s the essence of Zu Audio’s Soul MKII.

    They arrive dressed to impress. They keep their manners tight at family gatherings: they know when to say please, when to say thank you, to stand up when a lady enters the room……but they’re not afraid to swear or pinch yr Mom’s ass when no-ones looking. Ha! (“Mind your sass, boy”). Y’see, the MKII Souls are better deployed as classy party-starters, arriving with a keg under one arm, a couple of hot girls on the other. Loudspeakers for the music fan who digs the bombast of Skrillex as much as the gentility of Joni Mitchell.


    Associated Equipment

    • AURALiC Vega
    • Metrum Hex
    • Weston Acoustics Topaz
    • Wyred4Sound mINT
    • Peachtree Nova125
    • NAKSA 80
    • Magnepan MMG


    Audition Music

    • David Byrne – 3 Big Songs (1981)
    • Morrissey – Kill Uncle (2013 Remaster)
    • Pink Floyd – Wish You Were Here (2011 Remaster)
    • James Holden – RA.367
    • Zomby – With Love (2013)
    • Nick Drake – Way To Blue: An Introduction (1994)


    Further Information

    John Darko

    Written by John Darko

    John currently lives in Berlin where creates videos and podcasts and pens written pieces for Darko.Audio. He has also contributed to 6moons, TONEAudio, AudioStream and Stereophile.

    Darko.Audio is a member of EISA.

    Follow John on YouTube or Instagram


    1. Another great review John. I have a quick question, I’ve been a Zu zealot ever since I owned a pair of Druid Mk IVs. After email exchanges with Sean Casey – great guy and lots of fun to chat with – I have a pair of Zu Souls winging their way to me in China. I’m going to pair them with an AURALiC Vega and a Line Magnetic 518iA (845 SET) amp – bags of tone and a steal in China. The Souls are a perfect size for living here, but taming the base is always an issue with apartment living. You settled on yours with a 3mm gap, were you able to get them this low with the supplied ball-end footers?

      • Hey David. The ball-end footers aren’t supplied, they were store bought by me. To get ’em super-close to the floor I used some shorter spikes that I had tucked away in a box.

          • Thanks Mike. I’ll have another look in the box but the ones photographed in the review are mine. ALL MIIIIIINE. MWUAHAHAHAAAA.

    2. There are more compromises associated with single driver speakers than just limited bass. In fact that’s often the least of their problems as the bass can be enhanced by way of a horn or transmission line enclosure.

      The real issue with wide-banders is overall frequency balance issues combined with an inherent treble rise that can make them sound splashy or overly strident in the upper treble region. Most traditional loudspeaker manufacturers use some sort of qualifying spec in their frequency response measurements, something like 35Hz-20kHz (+/-3dB). It’s very rare that you’ll find any +/- qualifier from a builder of single driver speakers. Some don’t list FR figures at all. The reason they avoid using the +/- qualifier is that the results are pretty ugly, we’re talking swings in response on the order of +/- 10dB or more. It’s also very common for a single driver speaker to have a more gentle rise in response of at least 10dB from about 1kHz to 10kHz. This is why single driver speakers are often paired with very mellow tube amps. Aside from the fact that their ultra high efficiency makes partnerships with SET amps possible, they also benefit from the resulting roll-off in the highs.

      There are also other ways to get many of the benefits of a single driver speaker while avoiding many of the drawbacks. Reference 3A for example direct-couples the midrange drivers in their speakers to the amplifier without any crossover in the way. The tweeters take over by way of a single capacitor that acts as a high pass filter. Some other companies will use wideband drivers but only up to about 8kHz or so, making the crossover point at a much less musically damaging area than the usual 2kHz while letting a dome or ribbon tweeter much better suited to the job than a large cone driver take over in the HF range.

      Full range speakers are interesting and they can be very good values because there’s no need to spend any money on expensive capacitors and inductors and other crossover components, but ultimately multi-way speakers (given quality components) will sound better.

      • There’s is zero evidence of ‘limited bass’ with these Zus. Zero.

        As you say: “There are also other ways to get many of the benefits of a single driver speaker while avoiding many of the drawbacks. Reference 3A for example direct-couples the midrange drivers in their speakers to the amplifier without any crossover in the way. The tweeters take over by way of a single capacitor that acts as a high pass filter.”

        That’s effectively what’s going on here.

      • I guess, it depends on what you are really after (as stated in the review). I own Eclipses-TD (which, btw, honestly list their range at +/- 10 db) and, given the music I am listening to AND what I am trying to hear in that music, won’t change them for anything 🙂
        BTW, while they compare miserably to ZUs in terms of efficiency (all because of their mechanical design), they have a certain ‘room-cancelling’ capacity (due to that same mechanical design) which may be a huge advantage under some circumstances.
        There’s no perfect equipment, only perfect matches, with your self being the main ‘thing’ to match 🙂

        • I’ve heard some Eclipses and they are bloody brilliant with imaging and dynamics.

      • Some of us just listen to our speakers Dave, rather than worry about specs and design philosophy. My room measures far from an anechoic chamber and so it doesn’t matter how linear your ideal multi-driver speaker is, it won’t sound the same in my room as it does in yours. Have you even heard a Zu speaker? Sure they may be not be the last word in linearity, but they sure as hell sound good. I wouldn’t swap mine for anything.

    3. Hi John,

      Interesting and helpful review as usual, I am starting to wonder where the sweet spot in the new Zu range lies,given the new drivers now on offer. How do you think these mark two’s compare with the radian tweeter modles – have you had the chance to hear the Druid V or Soul Supreme to compare?

      • Hey Damo – you and I are thinking alike. I’m keen to hear the Druid V next.

    4. I haven’t done a direct comparison, but I’m fairly familiar with Zu speakers. IMO the radian tweeter makes a BIG difference. I spent a weekend with the Druid Mk V’s they were brilliant, dynamic and tonally just right. I really wanted a pair of Druid V’s but thought they were maybe too big for my apartment, plus the the price difference with the Souls is not insignificant. From what I’m the Soul Supremes are close to the Druids

      • Hi David that’s interesting – I’m planning to audition the Druid & Supremes if possible sometime in the next 6 weeks. i love the Zu sound and Vibrancy – chunky indeed!

        The big question is the price difference between the soul, soul supreme and Druid worth it to the listener for the 850, yur right given the current sepcial onthe mk 2 the differnece is more than the Mk2 current price. Your enthusiasm for the Druid has my senses keen but not my wallet.

        It’s encouraging that JD believes bass is not an issue with the Mk 2, I had considered Souls + undertone sub as a possibility. But i have not found my Omens to be wanting in bass for me- so I may not need a sub and that very wallet friendly.

        enjoying my Zu’s Damo.

    5. Once you get to the Druid end of the Zu range, things get very special indeed! I’m always happy to aim some the way of customers and reviewers alike 🙂

        • Could be special but at 7K it would want to be an end gamer!!!

          Unfortunately for me that is a real stretch and also brings a lot of competition.

          Love to see a review from Aus for the Druids.

    6. I have a new Reference 3A Decapo, with the direct coupled bass driver and tweeter with a single capacitor.
      It is ultra sensitive to placement, toe-in e.t.c and the sound can change dramatically, more so than other speakers I have had.

      Your comments about the Zu are similar, and they both have direct coupled drivers, so perhaps this type of design has this characteristic. I would love to hear these Zu speakers.

    7. These are some of the worst photographs I’ve seen in a review. How about applying some basic high school journalism skills and taking a picture of the entire product? Maybe one picture at a 45-degree angle? Maybe cut down on the hipster closeup shots? Thanks.

    8. Hi John, thanks for the great review. Quick question if I may. How do reckon these speakers would perform with a Trafomatic Experience 2? (this is your former amplifier that I have recently acquired)

      • Sasa Cokic knows how to make splendid amplifiers (hand-wound transformers being fundamental) and so the high-efficiency of Zu would make for a splendid match I reckon. The Souls would definitely dig a soupcon of 300B romance.

      • Hi,

        my Soul Supremes are running great on a Trafomatic E-Two, and I’m quite happy with the combo. ZU speakers really rock and what I like a lot is the hability to play all kinds of music.

        You would love them for sure.



    9. Hello. Very interesting review. But why don’t you mention the Wadia 151 in your list of recommended amp ? Because you don’t recommend it or …? On June 21st, 2 days before publishing this review, Zu Soul + Wadia 151 were the subject of another review. So in the end it would be nice to know how you rate this amp compared to the others to go with the Soul. My Soul MkII are currently powered by a Miniwatt N3 and I like it, but my N3 is having some problems so I need to replace it and was thinking about the Wadia 151 because I need a good DAC as well. Would be nice to know how you would compare N3/Wadia151/other amps with the Soul. Thanks

      • The focus of the Wadia + Zu piece was entirely different – minimalism, an amp that could be hidden. The Wadia has its own review too. If I were to make only one recommendation for the Soul loudspeakers it would be: go tubes!

        • Thanks John, very clear. I was hesitating between the Wadia and Peachtree Nova, I think your advise will drive me toward the Nova. They are offering refurbished at 599USD, I can even use it only as a DAC/Pre with my beloved Miniwatt N3 (if this one gets repaired) or as an headphone amp, and it has more versatile inputs. Merci !

    Minimalist hi-fi: Wadia 151PowerDAC Mini + Zu Audio Soul MKII loudspeakers

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