Zu Audio • Definition Mk IV Loudspeakers

by Roy Gregory | October 9, 2012

© www.theaudiobeat.com

Everybody seems to have finally grasped that designing an audio product is a precision balancing act. It’s not possible to create a product that does everything -- and the closer you get to that ideal, the less possible the resultant product is to afford, especially when it comes to loudspeakers. To paraphrase the bicycle trade, "Compact, wide bandwidth, high sensitivity, affordable -- pick any two." Except that with bikes at least you get two out of three -- the options being light, stiff or affordable -- which rather underlines the nature of the problem.

What fewer people grasp is that in reality this means that building systems (as opposed to individual products) is an even more precarious balancing act -- and nowhere more so than when it comes to the critical junction between amp and speakers. Build an audio amplifier that can drive a car up a hill, let alone any loudspeaker load known to man, and there are inevitable sonic and musical consequences to that design path. Try and solve or ameliorate those compromises and the amplifier’s price heads skywards nearly as quickly as its performance heads west. The eternal question facing any amplifier designer is, How much power is enough? Rapidly followed by, And what does it cost me in sonic and monetary terms to achieve it? -- at least assuming the designer possesses any musical or market sensitivity at all, which is far from a given.

You only need to take a look at the paper specs of most single-ended triode (SET) power amps to deduce that, for at least one section of the audiophile community, the answer to the cost equation outlined above is simple: too much! Hence the number of amplifiers out there with rated outputs in single figures. But whilst the theoretical benefits of low-power amplifiers, whether tube or solid-state, push-pull, single-ended or OTL, are well documented, it’s hard to ignore the chronic limitations the approach places on the end user when it comes to choosing speakers in the all-too-real world. Too often that choice dictates its own limitations when it comes to system performance, a "cure" that could easily be worse than the disease the adoption of low-power amplification treats in the first place. I know -- I’ve been there. As a long-time owner of the wonderfully engaging and musical Jadis JA30 monoblocks, I’ve experienced the frustration of trying to find their perfect partnering speaker -- and I know just how easy it is to throw their musical baby out with the loudspeaker bath water. The really scary thing is that at 25 watts in class A, they are positive muscle amps compared to the majority of single-ended 300B designs out there -- let alone 2A3 amplifiers and a host of even less powerful output tubes.

In practice, there are very, very few SET amplifiers that light my candle, the vast majority leaving me cold -- or should that be warm, cuddly and soporific? The Lamm ML2.1, several obscure Japanese designs and various Border Patrol models are the honorable exceptions to that rule -- amps that feature massive power supplies to back up their flea-powered output devices and price tags that reflect that fact. Which brings me right back to where this argument started, trying to get a quart out of a pint pot.

Now, I could argue the pros and cons of design responsibility until the cows come home; is it easier to build efficiency into a speaker or power into an amp? The answer of course is that it depends, but we’ll leave that for another day. Let’s just suppose for a second that you’ve bought into the low-powered philosophy; now you are looking for a speaker system that will deliver wide bandwidth and realistic levels at a price you can afford and in a cabinet you can (or your wife will let you) actually accommodate. Sitting, waiting for that bucket of coffee you’ve just bought to cool enough to actually sip, you idly jot down an outline spec for your dream speaker on the back of a napkin. Well, it needs to be efficient -- at least 95dB, and greater would be better. It needs to be full range -- obviously! But it also needs to have a small footprint so that it doesn’t take up too much room, and given that you’ll be dropping a $1000 a watt on the partnering amps, it can’t cost too much either.

What might surprise you is to learn that that speaker already exists -- and it’s called the Zu Definition Mk IV. Consider for a moment the following figures: bandwidth, 14Hz to 20kHz; efficiency, 101dB/watt; dimensions, 50"H x 12 3/4"W x 12 3/4"D; price, $16,000 per pair.

Now plug all of this into that original equation and you’ll see that Definition IVs do a pretty good job of delivering all four criteria --which should be next to impossible. Okay -- so sixteen grand isn’t exactly pocket money, but it’s way, way below market price for a speaker with this sort of bandwidth, let alone loudness capability (and Zu do offer equally efficient if less stentorian speakers at lower prices). Nor is it particularly large; it might stand a little over four feet tall, but its footprint is only a foot square and it stands dead upright. Add to that some serious versatility when it comes to near-wall placement and a vast array of finish options and you’ve got a speaker that while not exactly compact is remarkably easy to accommodate.

So exactly how have Zu defied, if not the laws of physics then the laws of the audio market?

Higher definition

My first contact with the world of Zu arrived in the shape of the Druid, a high-efficiency speaker that combined a 10" full-range driver with a horn-loaded tweeter to considerably entertaining effect. That led, seemingly inevitably, to a close encounter with the Definition Mk II -- a speaker that crammed not just an extra 10" unit onto its front baffle, but four 10" bass units onto its backside and a 120-watt amplifier into the bottom of the cabinet to drive them. If the Druid was fun, then the Definition wasn’t just Fun (with a capital "F") but Fun, Fun, Fun (to quote the song); in fact, it was a bit like being on the end of an ongoing musical Twitter feed all written in capitals. Here was a speaker that was short of neither attitude nor emphasis. You got seriously up close and personal with your music if you listened via the Definition IIs, mainly because the speakers gave you no choice.

Fast-forward to today’s listening room and the Zus are back in residence, but this time it’s a pair of Definition Mk IVs which, although outwardly similar (from the frontal aspect at least), are actually a totally different proposition to their previous incarnation. There’s a new and much better tweeter as well as a totally redesigned active bass leg, bracketing the same pair of Zu’s own 10" wide-bandwidth drivers -- and it is still those drivers that remain the key to the Definition IV’s astonishing performance, along with most of the other speakers in the range. Directly connected to the amplifier, with no subtractive crossover elements to impede efficiency or dynamic response, their nanotech-impregnated paper cone, supplemented by a central sub-cone, covers the spread from 30Hz to 12kHz -- the vast majority of music’s fundamental range -- at an efficiency of 101dB. Above that, a Radian 850 spherically horn-loaded tweeter is rolled in with a first-order filter. With a composite diaphragm and 3" voice coil, it has no problems keeping up with the midband. The bottom end is now handled by a downward-firing 12" bass unit, bolted directly into the speaker’s machined aluminum billet plinth and driven by a Hypex-derived class D amplifier. Placing the bass driver in its own separate internal volume and adjacent to the floor provides maximum boundary reinforcement, essentially making this a true subwoofer solution. As such it incorporates the full gamut of alignment and adjustment options you’d expect.

As anybody who has played with serious subwoofers will tell you, adjustment really is everything. The Definition IV’s active bass allows you to trim sub-bass level, rollover, phase and parametric EQ of gain and slope. That makes for a seriously adaptable bottom end at the cost of a daunting set of adjustments. Fortunately the speaker arrives with factory settings on the five rotary controls, and these allow you to work with bass integration in the traditional way -- simply by moving the cabinets. Tweaking bass level is easy enough and probably the most useful common adjustment that will be required. Beyond that, you really need to know what you are doing, with some sort of acoustic mapping of the listening space pretty much a prerequisite for achieving the best possible results. More importantly, before you do anything, make a precise note of the factory settings so that at least you can get back to the default position.

The good news is that the clean, tight, tuneful bass delivered by the Def. IVs actually integrates really well, managing to keep up with and deliver properly paced underpinning to the super-dynamic mids. I’ll admit that the move to class D amplification caused me some concern before the speakers’ arrival, but I really needn’t have worried. Zu have kept true to their "fun first" philosophy and that dictates bass that times and jumps convincingly. In my listening space, with no restrictions on placement, I didn’t need to resort to trimming the controls, beyond a tiny (and I do mean tiny) lift in bass level to add weight, but it is nice to know that the adjustability is there should you need it.

Each Definition Mk IV arrives in a substantial carton, completely encased in protective foam, a recognition of their significant weight. At 150 pounds each, they need to be treated with considerable respect, which, combined with the fact that they are not the easiest to manipulate (some speakers come with natural "hand holds" -- these don’t), makes installation a definite two-man job. I do this stuff all day, every day and I’m glad that I enlisted an extra pair of hands. There are two issues here: the aluminum base on the speaker is not kind to floor surfaces, while the significant weight means that even the rounded studs with which they are fitted on arrival will pit or score all but the hardest surfaces. Add to that the length of the spikes included and installing those requires tipping the speaker to a steep angle, again necessitating a second pair of hands, but I’ll return to that. The review pair arrived in gray Nextel, which contrasts nicely with the aluminum tweeter horn, driver surrounds and plinth, although a range of other shades, wood finishes and high-gloss lacquers is also available. I really like the industrial-chic/semi-pro feel of this pair, but I can see that it wouldn’t be to everybody’s taste.

Connections are via the rear panel, which offers an IEC input to power the bass amp, as well as a Neutrik Speakon connector for signal. This is one place where I seriously diverge from the Zu-view. Yes, the Speakon is a great-sounding connector and yes it locks in place -- but it’s a bear to terminate and that’s the main reason that nobody in domestic audio bothers with it. Which means that buying a pair of Def. IVs either means buying a pair of Zu’s Speakon-terminated cables (which could add nearly a $1000 to the price, depending on length), or having your own cables reterminated. Would it really compromise the product so much to offer a pair of conventional binding posts? Zu do offer Speakon-to-binding-post adapters (they are really very nice, at a price), but surely that defeats the whole object of using the superior connector in the first place.

Guys -- I appreciate the purist motives, but this is one situation in which you need to get real: give up on the fundamentalism and add a pair of binding posts. That way you are helping your customers rather than dictating terms, a situation that should make everybody happy. In fairness to Zu, I raised this issue and whilst adding standard terminals isn’t necessarily straightforward for space reasons, working out some sort of deal involving Speakon/Cardas adapters that might be swapped for connectors after the fact seems like a possibility. That way, at least you get to play with your new speakers while your cables are away being Speakoned.

In fact, just as the review was going to press (so to speak), I received word that from now on Speakon adapters will be included with all Def. IV sales -- yet another indication of Zu’s responsive attitude.

The billet plinth has all the appearance of a heatsink, although the Hypex-based amplification doesn’t demand one. Instead the grooves open onto the 12" sub-bass driver, allowing it to vent. Deep, threaded holes in each corner accept long, narrow spikes that will penetrate all known carpet materials and still give the downward-firing driver space to breathe, while domed posts are also provided for hard floors. It’s an arrangement that certainly provides a direct mechanical ground for the speaker’s sub-bass driver and its dedicated cabinet volume. Despite my wooden floor, I used the spikes (rather than the domed posts) in conjunction with Track Audio solid footers, allowing the driver as much space to breathe as possible. Lowering the driver closer to the boundary would reinforce bass weight and is a tuning option that you should keep in mind. Later, I also employed Stillpoints Ultra SS and Ultra 5s, to greater and greater effect.

So much for the physical description; what about positioning? Let’s not mince words here: positioning is pretty much make or break with the Def. IVs -- and you can forget most of your preconceptions. The depth and power of the bass will define placement within the room, with or without resorting to active adjustment, but that is only the start of the story. The horn-loaded tweeter beams like a laser. That means that not only do you need to be off-axis, but you must be off-axis by precisely the same amount, left and right, up and down. Start by getting the speakers absolutely upright and then you can start to angle them in. Unlike the vast majority of loudspeakers, the Def. IVs will want to cross their axes in front of the listener -- in my listening room, around 18" in front! A laser pointer, a real one this time, rather than the sonic equivalent, will be a huge help in getting the angles right.

I used the Zus with various amplifiers, ranging from the Jadis JA30s (fruity but fun) to the JE Audio VM-60 monos (capable of genuine rock-concert levels when required), but the real magic happened when I hooked up a pair of Berning 12-watt monoblocks. These chopped-down versions of the already special ZH-230s have elevated that amplifier’s exemplary midband transparency to a new high. Okay, so 12 watts are still 12 watts, even if they are very special watts indeed, but the active bass and extraordinary efficiency of the Def. IVs make them the perfect match for this "all about quality" approach to amplification.

In your face, but in the nicest possible way!

The one thing you can pretty much guarantee is that if you have a system with wide bandwidth and extreme efficiency, you’ll not be lacking when it comes to music’s more visceral elements. Your immediate reaction to that statement probably starts with a capital "B," but in reality the thunderous weight and rib-rattling bottom end that many listeners seemingly seek are quite different things. If you are talking visceral, then what you are really talking is speed: think Bruce Lee rather than Vitali Klitschko. When it comes to impact, velocity always trumps weight. Of course, if you could have both -- but then you’d be talking way more than the $16,000 price of the Def. IVs. The truly impressive thing about the sound of the Zus is not their thunderous active bass. As already noted, the bass is lean, tight and tuneful -- and light enough on its feet to keep up with the midband. What’s impressive is how quick and clean this speaker is; but what’s really impressive is that it’s quick and clean across its entire range. That gives music more than just presence. It delivers it with a real sense of purpose.

The Lonnie Johnson with Elmer Snowden album Blues, Ballads and Jumpin’ Jazz [Analogue Productions Revival Series APR 3001] is the perfect case in point. This 150-gram repressing of a 1993 Fantasy record, itself drawn from previously unreleased takes laid down during the Blues and Ballads sessions on April the 5th, 1960, is actually one of my favorite Analogue Productions blues titles. Its sparse instrumentation, just two guitars placed hard left and right, supported by an upright bass positioned back and between, presents a system with music that is at once an opportunity and a challenge. Here is an ensemble whose acoustic power most systems can actually match, but the flipside of that coin is that any shortfall becomes all too obvious. The Def. IVs paint a starkly vivid picture that crackles with immediacy and life. This is no artifact of "reach out and touch" soundstaging; this is all about the chemistry that exists between the players, the timing and attack, the precise placement of their notes next to and against each other. The off-mic conversations and control-room interjections add to that uncanny sense of natural rhythm -- the pace not just of the music, but of events themselves.

Now let’s take it up a notch. You want direct -- how about direct to disc? Analogue Productions again, but this time their direct-cut Arthur Williams with Jesse Hoggard [no catalog number]. If you want a solid, tactile presence from your system, direct-cut records are a good place to start. If you want to extend those attributes to the nth degree, then the Def. IVs will definitely take you there. Just listen to the opening track, the familiar "I’m a King Bee" -- but delivered here with a slower, almost stately growl that contrasts markedly (and effectively) with Jagger’s more frenetic version. That loping, almost lazy guitar line never sounds slowed or sluggish, its easy, almost insolent nonchalance making its own emphatic statement of intent. Voice and guitar are perfectly scaled, with a "shut your eyes and you are there" presence that is only enhanced by the longer notes and plaintive wail of the harmonica. You want blues? This is the blues -- raw and direct.

Of course, just as the Def. IVs are a window onto the (very mixed) qualities of your recordings, they’re also a window onto the quality and style of the driving system. What I’ve just outlined above has a huge amount to do with the incredibly quick and lucid sound of the Berning amps. Swap in the Jadis JA30s and you get a kinder and more cuddly view of events -- but I’m not sure that you are making the most of either partner in that particular marriage. The Def. IVs don’t excel when it comes to allowing those richer harmonic colors to bloom, while the amps might get the notes in the right place, but not with the laser-like temporal precision that the Bernings provide. The Jadis are all about the midrange, whereas the Bernings’ raison d’etre is seamless top-to-bottom transparency and continuity. That’s a quality that they share, at least in dynamic terms, with the Zu speakers, which is what makes the combination so special. The warmer bottom end of the Jadis amps might add some extra weight to proceedings, but it’s weight the Zus make you aware shouldn’t really be there.

Yes, it’s tempting to take one look at the Zus’ spec sheet and reach for the first flea-powered SET you can find -- or vice versa. But do that and you’ll only be getting half the story. Yes, the Def. IVs will work with really low-powered amps -- but what they need is a really articulate one. The Bernings stand out in this regard, but I’d love to hear the Zus with one of the Nelson Pass single-ended solid-state designs like the old Aleph 3 or the new SIT, the DNM amps, or Avantgarde’s sadly defunct 30-watt integrated amp -- a device that took crisp precision to new heights. Tubes might be the obvious partners, but really quick, uncluttered solid-state amps from the likes of Lavardin will show you a whole new and powerful side to these speakers. As far as partnering amps for the Def. IVs go, it’s all about quality and agility, not how many (or how few) watts or the topology and devices generating them. Quick and clean is the order of the day.

Shifting up

The simple rhythms, angular chords and open space of simple blues recordings make the most of the Zus’ stop-start agility and speed of response, showing the speakers’ strengths to maximum advantage. Move up a notch in terms of complexity and the turn-on-a-sixpence characteristics might not be so obvious, but other qualities emerge. Let’s take this a step at a time. "52 Girls" from the B-52s' eponymous first album [Island ILPS 9580 -- an original pressing] clearly shows the sheer pace and attack of the Def. IVs. The taut insistence of the backing has a staccato, almost machine-gun quality to it that displays not just the temporal precision of each note’s placement, the precisely repeated pattern the notes create, but also the solidity and dynamic heft behind them all. The chopped rhythm guitar has serious substance and drive, a world away from the limp fluffing that you so often hear from poor recordings on poor systems. The term "rhythm" guitar actually starts to make sense, while those one-bar drum breaks deliver a simple yet astonishingly effective percussive impact, a sharply contrasting cannonade of sound. What passes like a dip in the road on most systems is transformed into the stark dynamic shift caused by hitting a speed bump five miles per hour too fast. It’s not just the substance, it’s the ability of the speakers to shift character and density with the music, giving dynamic and tonal contrasts real significance. It’s a quality that few systems achieve, yet it underpins so many atmospheric shifts in music, both live and recorded. The distant, almost chanted chorus vocals on the track give it a distinct personality and feel; the Zus leave you in no doubt whatsoever that this is an entirely intentional effect.

Let the needle run through to the next track and watch the clouds roll in. Gone is the jangly brassiness of "52 Girls," replaced by the brooding intensity of "Dance This Mess Around." Just listen to the difference in the vocals. Suddenly they’re immediate, breathy and intimate -- too intimate to ignore. There’s an almost disturbing, space-invading, manic bunny boiler intimacy to the song, underpinned by the slowly building, increasingly claustrophobic density of the layer-on-layer production and shouted backing vocals. Anybody who thinks the B-52s are all just "Shiny Happy People" should really think again -- and the Zus tell you that in no uncertain terms. Their ability to mine the atmosphere and emotional intent behind the music is almost uncanny, a quality that leaves many speaker systems sounding emotionally emasculated.

It applies to more than just the dark underbelly of alt-pop too. One of my currently continuing guilty pleasures is the Kertesz/VPO Dvorak New World Symphony from the Decca Sound box set [Decca CD 24, 478 3179]. This is a great transfer of a familiar recording, yet the Zus still manage to conjure an impressive sense of surprise and shock at the first-movement tuttis, the explosive dynamic shifts, while the switches in mood that are so characteristic of the sweep and scope of the piece are more apparent and that much more effective as a result. Naturally, Kertesz’s poise and timing are almost reinforced by the Zus’ emphatic delivery, but what this disc also shows is the way in which the speakers’ musical preferences impact on presentational detail. The classic Decca soundstage is narrowed here -- and deepened. But what is much more obvious is the way that, while instruments are clearly separated in space, the coherence of that space, the distance between them and the sense of air around them is curtailed. Stereo spread -- the locational positioning of instruments or voices -- takes precedence over the impression of overall acoustic. This is true whether you play those early blues albums, jazz or modern classical recordings. You’ll never confuse one instrument’s position with that of another -- just think back to the totally clarity of separation between the two female vocals on the B-52s and you’ll see what I mean -- but this is a different kind of separation and placement to the "locked in a single space" or "tonal separation" that other speakers/systems rely on.

Which brings me to the price you pay for the Zus’ considerable strengths and magnificent musical impact. Play a familiar vocal -- in my case I’ll use Janis Ian singing "At Seventeen" (Between the Lines, [Boxstar 88697691871]) -- and listen to the character of the voice. There’s a slightly clipped quality, a subtle hollowness or coolness, almost as if the recording was made in a cold acoustic. But I know that it wasn’t. I also know that the brass on this track is robbed of some roundness and color, the guitars of some shape. It’s a subtle harmonic stripping -- and I do mean subtle -- that helps the speaker deliver that sense of presence and impact, speed and precision. It’s never clogged or slowed by unnecessary baggage, but that’s because it packs light in the first place. Likewise, Eleanor McEvoy’s dusky contralto loses a little of its husk, Julia Fischer’s Guadagnini sounds more like a Strad.

These are subtle distinctions, but the effects are real enough. Of course, you need pretty good references to pick them up -- be that familiar material or really topflight alternative speakers -- but they should inform any serious consideration of the Def. IVs. That’s not because they are particularly intrusive or damaging, but because they are particular and they might well lead you to false conclusions or temptations. But before I go there, let me just make one crucial point -- again. In many ways the Def. IV’s saving grace is the fact that it is so consistent top-to-bottom. Despite the numbers for bandwidth (no limits supplied!), Zu has resisted the temptation to pump up the volume and deliver more bass weight at the expense of speed. It’s a decision that has made this speaker what it is -- and one you shouldn’t disregard. Don’t play with the bass parameters just to get more quantity; the overall performance will suffer -- dramatically (in every sense of that word). Even tiny shifts in the settings have quite audible impact -- and if you get it wrong the speakers tell you so, clearly and unequivocally.

The second great temptation facing Zu owners is the evil known as compensation. The speaker strips a layer of harmonics, so a certain logic suggests that using an amp that’s rich in second harmonics will compensate. No. No, no, no! All you will do is add a layer of warmth and wooliness to the sound. The harmonics you are adding are not the same as the missing ones; they are just covering -- or in the worst case, blanketing -- the crack. Wrapping an anorexic model in a four-ply cashmere pullover doesn’t make her look well-fed -- it just means you can’t tell what shape she is. Mixing warm components with cooler ones in some forlorn attempt to equalize the sonic temperature just bends things out of shape. Putting a warm and wooly amp on the Zus will take one subtle wrong and make it much, much worse.

Instead, I’d argue that these speakers represent an incredibly carefully considered balance of virtues. Like all balances (and all hi-fi) there are downs that correspond to every up. Hopefully, as prices climb, the ups increase and the corresponding downs diminish. With the Def. IVs that is definitely the case -- but no product eliminates every compromise or weakness. The fundamental principle behind constructing an entertaining and truly rewarding system is to pick the products whose priorities align with your own and then exploit those benefits for all you are worth. The last thing you should do is try and correct those deficiencies elsewhere in the system. Otherwise you’ll end up with the musical equivalent of a Cabbage Patch Doll.

Having said all that, there are two areas in which you can work with the sound of the Zus. One is cable choice. I ran the Def. IVs on the end of my regular Nordost loom, a setup that really made the most of the speakers’ speed and dynamic discrimination -- displaying both their strengths and weaknesses with as deft a hand as normal. Running them with Zu’s own cables dialed back the resolution and lightning speed without impairing the rhythmic integrity or sense of solid presence. The other area that is worth thinking about is cartridge choice. Again, there’s no question that the Clearaudio Goldfinger’s detail, dynamics and articulation play straight to the Zus’ strengths, but I also ran the company’s own re-bodied Denon DL-103 with exceptionally good results, especially considering its relatively modest price. Its more mids-prominent balance and slightly rounded presentation again took the sharply defined edges off of the Def. IV's presentation for a less extreme and more "normal" overall balance. The benefits of the cartridge are most noticeable on voices, so Janis gets a warmer, more familiar tone, albeit still with that hint of coolness. I’m not sure if the cables and cartridge aren’t too much of a good thing when used together; but then I’ve got the benefit of having glimpsed just what these speakers can do in a stripped-down racing snake setup. I’d probably opt for one or the other -- which is kind of cool, given that the speakers will find themselves on the end of both dedicated analog and also digital front-ends. This way you can choose the most appropriate match for your circumstances, both options punching well above their price point in the context of their matching speakers.

Doesn’t this fly in the face of everything I decried earlier as regards compensation? No -- because these are known quantities, not the result of inspired experimentation or simple guesswork. The cables and cartridge both played a central role in the Def. IV’s development, meaning that their DNA is deeply imprinted on the speaker itself.

You can tailor the Def. IVs’ presentation, but in doing so you are also contracting and diminishing their performance, and I believe that’s a big mistake. Like sugar in your coffee, it sweetens the drink but kills the flavor. I’d open that window just as wide as it’ll go -- and drink in the view. As a designer you can balance a product in any number of different ways; the Zus choose to lean in a different direction to the rest of the crowd and therein lies their appeal -- the invitation to do it differently and see the musical world from a different perspective. When it comes to system matching and the Zus, I’d be leaning the same way, not trying to haul them back to upright. As far as I’m concerned it’s a definite case of "Full speed ahead and damn the torpedoes!" Given the edge-of-the-seat quality that the Def. IVs bring to the listening experience, I think that’s a sentiment that Zu themselves might well approve.

End notes

The Zu Audio Definition Mk. IV is as individual as it appears and as its numbers suggest. It has a clearly stated and realized vision of what is musically important -- a vision that contrasts sharply with audio’s middle ground. But for all the extremity of its view, its also speaks with a persuasively musical voice, one that challenges the shortcomings of more conventional approaches. In the end it’s a perspective that may well convince you, either through the emotional and communicative power of its presentation, or through the opportunities it allows in terms of partnering equipment. Even if ultimately you choose to go another way, I can’t believe that the Zu experience will leave you poorer in terms of musical understanding, or understanding the weaknesses it exposes in other products and approaches. As a speaker whose ups coincide precisely with so many other speakers’ downs, it may or may not be your cup of tea. But for those who get what the Zu is all about, I suspect that once heard it’s an experience they’ll never forget (or forego).

Price: $16,000
Warranty: Five years parts and labor.

Zu Audio
Ogden Commercial Ind. Pk.
3350 S. 1500 W.
Ogden, Utah 84401
www.zuaudio.com

Associated Equipment

Analog: Clearaudio Goldfinger Statement turntable, Lyra Dorian Mono and Zu 103D cartridges, Connoisseur 4.2 and Aesthetix Janus phono stages.

Digital: Wadia S7i CD player.

Preamplifiers: Connoisseur 4.2 and Aesthetix Janus.

Power amps: Jadis JA30, Berning 12-watt and JE Audio VM-60 monoblocks.

Cables: Complete loom of Nordost Odin from AC socket to speaker terminals. Zu Event interconnects and loudspeaker cables. Power distribution was via the QRT QB8, with a mix of Qx2 and Qx4 power purifiers and Qv2 AC harmonizers.

Supports: Racks are 26" wide Stillpoints ESS (current and original versions) and Leading Edge modular designs. These are used with equipment couplers throughout, either Stillpoints or Nordost SortKones. Cables are elevated on Ayre Myrtle wood blocks.

Accessories: Essential accessories include the Feickert protractor, a USB microscope and Aesthetix cartridge demagnetizer, a precision spirit level and laser, a really long tape measure and plenty of masking tape. I also make extensive use of the Furutech anti-static and demagnetizing devices and the VPI Typhoon record-cleaning machine. The Dr. Feikert PlatterSpeed app has to be the best ever case of digital aiding analog.

A lot of speaker for the money

Just take a look at the material content in the Def. IVs and you start to wonder how Zu does it for the price. In-house drivers, active bass, machined aluminum fitments and a complex multi-layered cabinet in place of the more generally used MDF adds up to a lot of cost. As I said, $16,000 is hardly pocket change, but it’s around half what you might expect to pay for a speaker system with this bandwidth from other sources. Even the bigger producers like B&W (the 800) or KEF (the Blade), with all their economies of scale, can’t get close to that sort of price/performance balance -- and definitely not in a speaker this efficient and versatile. Are Zu cutting corners, delivering a "never mind the quality, feel the width" solution to a customer base that’s pretty much over a barrel when it comes to speaker choice? While there’s certainly a price to pay for that sensitivity in terms of tonal neutrality and harmonic sophistication, that pretty much goes with the territory. In fact, Zu achieve a far more neutral and better-integrated output than many of the horn loudspeakers that constitute their competition. So, once again, how do they do it for the price?

The answer is actually very simple: they sell their speakers directly to the end-user, cutting the dealer and the dealer’s margin out of the equation. That definitely makes for a more affordable product, but as an approach, it is not without its downsides. Great news for anybody in America, it’s not so great for anybody living anywhere else in the world, who will end up paying considerably more for the same product, unless they want to buy it blind and take on the not inconsiderable cost of shipping and duties. It also means that you don’t get the security of dealer support -- delivery, installation, backup in case of damage or destruction, not to mention advice as regards system matching and the benefit of embedded experience. Each customer can make his own decision on this, weighing his own experience and the proximity of his dealer against the value that dealer can add to the sound of the system; I’d just caution that you don’t underestimate a dealer’s contribution -- especially if it involves shipping a pair of speakers that weigh 150 pounds each back to the manufacturer for repair. Generally speaking, if everything runs smoothly, and this really is the speaker for you, then it’s a no-brainer. But if the wheels do come off, just be prepared to clean up the train wreck.

However, two things help mitigate this situation. Firstly, Zu are remarkably helpful and responsive. Given my feelings as regards the Speakon connectors, not to mention my own personal fetish when it comes to cabling systems front to back with the same wire, Zu built and supplied me with a set of Speakon/Cardas binding-post adapters so that I could use my normal cables, as well as enough interconnects to add to the already supplied speaker cables so that I could wire the system entirely with a complete Zu signal loom. Not particularly remarkable, except that they managed to get them all here in the space of three working days -- from Utah all the way to rural England!

Secondly, Zu Audio is embarking on European production of its speakers. Initially this will only encompass three base models, but assuming that the experiment is successful, it will allow Zu to supply European dealers at prices that will make the retail cost equivalent to buying and shipping the speakers from the US -- and that’s got to be good news.

-Roy Gregory

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