KEF Blade Loudspeakers

by Roy Gregory | September 28, 2012

© www.theaudiobeat.com

KEF has always been a part of my hi-fi journey -- maybe not a constant companion, but definitely a fellow traveler, a familiar face one greets with a certain affection. It started with the Reference 104aB but really hit its stride with the 105/2, an unobtainable object of desire. This was the speaker that first established the now-familiar stacked format for three-way floorstanders, each driver with its own, separate enclosure. Yes, I got the concept, and the independent head unit made perfect sense, but truth be told it was the 12" bass driver that stole my callow heart. After that came the 104/2, a radical departure that introduced tall slim cabinets, coupled-cavity bass loading, a flying baffle for the midrange and treble units and Conjugate Load Matching -- a compensation network designed to present the driving amplifier with a flat, purely resistive load. Throw in the KUBE active bass equalizer and a 92dB efficiency and you had a speaker that was possibly too far ahead of its time for its own good.

But it was with the arrival of the 105/3 that things got serious. This speaker took the basic form of the three-way 104/2 and expanded it, incorporating the new UniQ coincident driver into an ambitious four-way flagship. It was the first KEF speaker that I reviewed and the first I lived with long-term. In fact, they’re still in the storage unit as, like so many of my hi-fi "partners," I’ve never brought myself to part with them. Looking back, it’s easy to dismiss the 105/3 as a commercial failure, but that would be missing the point. If ever a product suffered from an industry that habitually shoots the messenger, the 105/3 was it. Rather than fastening on the technology built into the speaker, look at the motivation behind it. The UniQ driver, set in a D'Appolito array with a pair of bass-mid units of identical diameter and above a bass port, again of the same diameter, indicates a major concern/investment in the dispersion of the system, while the number of drivers and the coupled-cavity loading increase system efficiency and dynamic range; but more than that, the force-canceling arrangement inherent in the coupled-cavity design, along with the decoupled flying baffle, promised clean low frequencies and freedom from intermodulation distortion. The 105/3 was designed to deliver realistic dynamic range without the slurred rhythms and stodgy response that comes from poorly behaved conventional cabinets. It traded bandwidth for efficiency (and tried to claw it back via the KUBE), but above all it sought honest reproduction -- which is exactly what got it into trouble.

The 105/3 was a remarkably capable but brutally honest and revealing transducer. For a reviewer, it was a boon, instantly revealing the character and characteristics of partnering equipment, whilst also teaching the hard lessons of system setup, ancillary quality and consistency of approach that inform everything that I do today. But that same quality killed it commercially. Picture the scene: the keen KEF rep lugs his new reference product into a dealer, who hooks it up to the ill-assorted mish-mash of kit that happens to sit in the demo room -- whereupon the speaker sounds exactly like the bag of spanners it’s connected to! What do you reckon is going to get the blame? Which was the cross the 105/3 had to bear, and eventually crushed it under the load. Here was a highly capable speaker, at an incredibly affordable price, able to challenge some of the best high-end designs then extant, but never given the opportunity because it rarely if ever found itself on the end of those systems. The industry didn’t shoot the 105/3; it just slowly choked it to death.

Perhaps it should have come as no surprise that shortly after the 105/3’s launch in 1989, KEF fell victim to economic hard times, ultimately being acquired by the Hong Kong-based Gold Peak in 1992, just after they’d also bought that other British landmark, Celestion. Whilst this brought much-needed financial stability, it also heralded the eventual demise of UK production, at least as far as mainstream product goes. From their vantage point in Hong Kong, and with major manufacturing interests, Gold Peak were well positioned to see which way the wind was blowing, and in 1998 major UK manufacturing ceased, ironically on all models save the Reference 109 Maidstone -- a speaker whose major market was the Far East. More importantly, the key R&D facility at Maidstone was retained and remains at the heart of every new product KEF develops, giving continuity to the technology and product lines -- a continuity that is clearly apparent in the Blade.

The shift to Chinese manufacturing saw the company rebuilding from the ground up, with a host of impressive mainstream products utilizing KEF’s proven acoustic engineering and technology, especially UniQ drivers, at far more approachable price points. During this period, the Reference-series speakers were largely left to fend for themselves. The 200 models were the last major revision, back in 2001, with refinements added in 2006. They may not have been the most fashionable products around, yet for those who bothered to listen they represented a serious bargain, especially when compared to the higher-profile (and higher-priced) competition.

The first stirrings of something new at (or beyond) the upper reaches of the range appeared in 2006 at the Munich show, in the unlikely shape of the Austin prototype, a massive (and prodigiously ugly) columnar four-way speaker system, complete with a pair of rear-firing woofers to augment the four on the front baffle! Ultimately, Austin (named for Austin Powers) was to transmogrify into the "carved from a solid block of aluminum" Muon, with stunning looks and, for a KEF product, an equally stunning $198,000-per-pair price tag. As much sculpture as acoustic engineering, the limited-edition Muon might not have received universal regard for its sonic prowess, but it was significant in other ways. KEFs astonishing resurgence at the lower end of the market and in the A/V realm meant that many people had forgotten the brand as a serious two-channel contributor. If the Muon was designed to attract attention and restate, in no uncertain terms, KEF’s commitment to the two-channel format, then it succeeded handsomely. But more importantly, the Muon marked the introduction of a new UniQ driver with significantly improved dispersion, and along with the rear-facing bass units, this indicates the company’s continuing interest in the question of dispersion and directivity.

Studying the form

Which brings us, finally and somewhat circuitously, to the Blade. The Muon was more of an attention grabber than a real-world product, but the Blade is very real indeed. It needs to stand or fall on more than just its looks. Fortunately, those looks owe more to the engineering and technology involved than the stylist’s pen, and the Blade is very much an exercise in Bauhaus concept meeting production engineering.

Why the extended history, the tour through KEF’s greatest hits and a few of their trials and tribulations? Because in many ways the Blade conjures up (personally at least) such strong echoes of the past. Ignoring form and content for a moment, this speaker has an awful lot in common with the 105/3: it delivers a lot of technology and engineering in an unorthodox and striking package. It looks different and it is very different from the run-of-the-mill. But perhaps the most telling similarity is in the pricing. Many years ago I quizzed a manufacturer as to why his (admittedly excellent) product was so expensive. After a protracted discussion in which several justifications were advanced -- and summarily demolished -- in frustration he blurted out, "It needs to cost that much or customers won’t take it seriously against the competition!" He’s not wrong. Someone looking to spend $70,000 on a pair of speakers might be persuaded to spend $80,000 -- but try making that person believe that he can get that sort of quality for $30,000. It’s a very hard sell indeed. Its brutal honesty did the 105/3 no favors, but the very qualities that undermined its performance at its approachable price were regularly lauded in products at five times the price. It’s just that nobody thought to make that comparison.

The KEF Blade costs a not insubstantial $30,000 per pair -- not exactly chump change, but a bargain compared to its performance peers. Believe me, this is one extremely impressive speaker system. Measure it any way you want: sonic performance, unique technological content, materials, parts cost or execution. This speaker stands comparison with a lot of models at between two and three times its price. How does it do it? Partly through innovation, partly through the confidence to commit to large-scale production -- production and assembly, incidentally, that take place entirely in the UK. So, in the same way that B&W can fit diamond tweeters in speaker models at a fraction of the price charged by the competition, by making their own drivers and lots of them, KEF have applied the same logic to the Blade. High time then to look at the substance of this product in detail.

Despite its striking appearance -- the Blade stands 62 1/2" tall and is only 14 3/8" wide at the foot, less for the cabinet -- the speaker’s form definitely follows -- indeed, it’s dictated by -- its function. It is built around an advanced UniQ coincident driver, located in its narrow, curved front face. This unit is a further evolution of the one used in the Muon and advances UniQ performance to an entirely new level. The tiny, 125mm (5") midrange diaphragm is formed of a lithium/magnesium/aluminum alloy, with a web of rear-mounted liquid crystal polymer ribs helping to stiffen the cone. Driven by a 75mm (3") voice coil, the "nodal" diameter of the diaphragm does not move in its first resonance, ensuring fully pistonic motion throughout its passband and beyond. The matching tweeter nestling in its throat is a carefully shaped aluminum dome that changes in the profile, extending useful output to well beyond 30kHz. The Tangerine waveguide -- so-called for obvious reasons -- helps smooth and widen the dispersion, better blending the transition between the two drivers. The complete unit is mounted in its own decoupled sub chamber, faced with a carefully contoured rubber mat, designed to further reduce cabinet-diffraction effects.

So far so good -- and fairly familiar; KEF have been playing with reduced and curved baffle areas for quite some time, albeit without taking things to quite this extreme. Of course, the reduction in driver diameter helps, down from 165mm (6 1/2") in the Muon, but the attention to detail and clean final result are still impressive. Where things take a radical departure is in the low-frequency arrangement. It’s hard to miss the four 9" aluminum dish bass drivers, paired two on either side of the extremely slim but deep cabinet. Look closely and you’ll see that they’re also symmetrically disposed above and below the UniQ driver. The result is the nearest thing that KEF can create to a full-bandwidth coincident source -- and that makes the Blade a very unusual device indeed!

The bass drivers themselves bear closer scrutiny. The 9" diaphragms are each driven by a massive 4 1/2" voice coil, a size more normally found on 15" drivers. Add the fact that there are four such drivers per speaker, and thermal compression really shouldn’t be an issue. The drivers themselves are arranged back to back across a cabinet that’s only just broad enough to accept them, creating a force-canceling arrangement of the type so frequently employed by KEF. By tying the drivers together in physical opposition, they cancel each others' reactive mechanical output, output that would otherwise find its way into the cabinet and via that back into the drivers -- after a suitably damaging time delay.

The cabinet itself is a composite construction based on a fiberglass front and back clamshell, its curved surfaces stiffened by significant internal bracing. The internal volume is divided into two discrete bass chambers, by a substantial horizontal brace, each section driven by one pair of drivers and loaded by a heavily contoured, rear-facing port. The careful shaping of the cabinet and the severe step in the horizontal brace minimize parallel surfaces and internal standing waves, reducing the need for internal wadding or other absorption. The two smaller cabinet volumes also serve to raise the resonant frequency of the structure well outside the driver’s passband.

Taken together, these measures should deliver a notably clean, fast and uncolored bass, spatially and temporally integrated with the mid and treble. It should also be relatively untroubled by loud passages or sustained use at high levels -- not because the designer fondly hopes so, but as a result of solid basic engineering mixed with a dash of inventiveness when it comes to physical configuration. You could say that no single element of the low-frequency system is exactly rocket science, and in essence each and every part is a logical extension of established KEF practice, but once assembled, they definitely constitute a rocket.

The crossover carries the normal blanket claim regarding carefully selected high-quality parts. More importantly, the slopes are shallow quasi-first order, and thus phase coherent. The crossover itself is mounted on the base of the cabinet, sealed in its own separate chamber. Four WBT binding posts are provided for each speaker, allowing for biwiring or biamping. Rather than linking plates, neat screw-in shorting plugs are provided for use with single-wired cables.

The cabinet stands on an inert, molded polymer foot. This accepts a quartet of M8 spikes that can be adjusted from above (with the supplied Allen driver) and locked off with large knurled discs. Felt-faced footers are also supplied for use on hard floors, the whole kit being encased in a beautifully black-lacquered box. The threads on the supplied spikes are sufficiently short that using the massive and very thick locking discs severely limits the range of available adjustment, while the spikes themselves could be improved. The Blades deserve better and I used a set of eight Track Audio M8 spikes ($129 each) along with their matching, hard-coupled footers to good sonic effect. KEF is aware of the issue and are looking at alternative spikes. Importantly, a small spirit level is embedded in the rear of the speaker’s base. Absolutely vital (there isn’t a single horizontal surface anywhere on the cabinet) it makes getting the speaker vertical an absolute doddle -- a good thing not just sonically but visually too. With a cabinet this narrow, you really notice if it’s not standing up straight.

Getting to grips

The Blades present the practiced listener with a perceptual challenge: we look, we see, we expect, but what we expect and what we receive are two rather different things. The Blades don’t sound the way you think they will -- or at least the way I thought they would. Instead they sound distinctly different -- and significantly better! The key lies in their character as a coincident source. With the speakers setup and dialed in (on which more in a moment), I was haunted by a strange sense of familiarity. Having listened to a lot of very good -- and very conventional -- box speakers recently, the Blades were obviously different, but different in a way that jarred my expectations. I recognized the quality, I recognized the natural perspective and presentation, I just didn’t associate it with the form of the speaker in front of me. Until it dawned on me that I wasn’t having to apply the subconscious corrections or make allowances for the cabinet format. I’d heard this style of presentation before, and to seriously murder a quotation, "Temptation -- thy name is Quad."

Perhaps it should come as no surprise that the Blade and Quad share certain presentational DNA. After all, the Quad is one of the very few other coincident-source loudspeakers out there. Of course, in this instance I’m talking real Quads -- ESL63 rather than the ELS57 "midrange units" so beloved by many. I’m also talking about '63s that have been properly treated, which means getting them 18" off the floor, removing their cap and socks and giving them a decent power cord. Do those things and the results are quite remarkable -- especially when it comes to the coherence and natural dimensionality of the soundstage.

The Blade doesn’t sound like a Quad ESL63 -- unless it’s a '63 that suddenly grew bass and a pair of serious cojones to go with it. This is a speaker that does instrumental scale and dynamics for fun, but grafts them onto the spatial coherence and seamless continuity of the legendary electrostatic. And it doesn’t just add extension to the mix -- at both ends of the range; as well as matching the '63's spatial prowess, it matches its ability to sonically disappear too.

So what exactly is this "difference" I keep referring to? Where most speakers "sit" their soundstage on or just above the listening-room floor, the Blade sets the acoustic higher, floating it entirely independent of the room boundaries. At least a part of that difference is down to the way that conventional designs produce bass and use the room boundaries to reinforce it. With the best examples we hear an independent acoustic, but that’s because we mentally airbrush out the physical boundaries -- and their relationship to/impact on the stereo stage they create. It’s a catch 22 if ever there was one: you need real, deep bass to float a convincing soundstage; you need boundary reinforcement to achieve deep bass without a massive cabinet. Which is why, of all the speakers I’ve spent time with at home, only the Focal Grande Utopia EM and Avalon Isis have really created a truly independent soundstage -- and only the various Wilson Alexandria models have done it consistently in other environments. They’re all big and they’re all seriously expensive.

The Blade is a fish of a different flavor. First, its bass drivers are a lot farther from the nearest boundary than most other speakers' -- especially speakers in its price class. Second, without the benefit of boundary reinforcement, the Blade relies on swept area to generate bass -- hence those four large, long-throw and extremely powerful bass units a side. Even so, its low-frequency numbers seem pretty modest in comparison to the competition, with a -3dB point at 40Hz. The difference lies in the quality of the bass produced -- and the fact that the -6dB point of 28Hz suggests a slower roll-off than most reflex cabinets provide. It’s not just the lack of room reinforcement, but also the quiet cabinet construction, the force-canceling driver arrangement and rigid structure, meaning that the enclosure doesn’t join in with the bass notes. Not having to rely on the variable quality of boundary interface and placement, the low frequencies generated by the Blade are notably linear and free of flabby weight or exaggeration, sounding deeper than the numbers suggest. This is all about quality, with tone, pitch and texture notably more natural than we’re used to from all but the very best speaker systems.

The absence of weight (and the massive motor assemblies) also gives the Blade’s bottom end genuinely explosive potential. Impact rests on a combination of weight and speed, and what the KEF might lack in terms of sheer weight, it more than makes up for with the sudden arrival of its bass transients. Just listen to orchestral percussion and you’ll see what I mean. Big timp rolls are rich and complex as they explode from their clearly defined space at the back of the orchestra, the texture of the skin, the mallets and the enclosed air all clear to hear. The way they punch through the acoustic space, the way they remain stable and locked in place, the sheer independence of their sound make the Blade’s delivery one of the most convincing I’ve ever heard.

All of which rather skews the setup priorities. The Blade delivers its bass performance if not independently of the room, then with significantly less impact from its placement. It’s all about limiting room excitation rather than augmenting the speakers’ output. Using the Wilson approach to speaker placement, my listening room exhibits 8" pockets. Ideal lateral spacing corresponds to conventional speakers, but moving the Blade backward and forward in those 8" steps doesn’t impact bass weight so much as how that weight is distributed, with linearity being clearly superior in the optimum position when compared to either the next fore or aft option. So rather than looking for a balance of weight and pace/attack, the qualities you are balancing are linearity and continuity with the soundstage as a whole. Get it right and the soundstage simply floats free as the bass instruments step into place.

The other key positional issues are toe-in and rake angle. In the case of the latter, the first and most important consideration is that this angle should be identical for both speakers. Starting with them vertical, experiment with tipping them forward a little at a time, gauging the increments using the bubble and ring on the spirit level. Again, get the angle spot on and you’ll hear the soundstage lock into place, even on a studio recording. My listening room/seat certainly demanded a small degree of forward tilt. I also ran the speakers well toed-in, pointing just outside my shoulders when seated in the listening position. The LEDR tests (available on various test CDs) proved invaluable in this regard -- as always.

With the Blades positioned just so, it was high time to have some fun -- but first a short digression on matching amplification.

Making the connection

Taking another look at the KEFs’ on-paper specs, there’s nothing here to frighten an amplifier -- or so you’d think. Sensitivity of 90dB with a nominal 4-ohm load and a stated minimum impedance of 3.2 ohms is hardly the stuff of electronic nightmares. But don’t get lulled into a false sense of security. The Blades are more demanding than those numbers suggest, and if the matching amp fails to meet those demands, the speakers are quick to let you know.

As with a lot of really clean, low-distortion designs, it is hard to get a handle on how loud the Blades are playing. It’s easy to play them very loud indeed, especially given their overall coherence and lack of thermal compression. But do it with the wrong material and the wrong electronics and suddenly the tweeter steps away from the rest of the range. Driven hard, the high frequencies can harden, taking on an edge that pushes instruments forward in the soundstage with a jarring sense of discontinuity. Now clearly, in part at least, the Blade is a victim of its own success here. If its soundstage wasn’t so incredibly natural and contiguous, that positional shift, the sudden separation of an instrument (or instruments) from an otherwise seamless acoustic space wouldn’t be as obvious and wouldn’t be nearly as disturbing. But as it stands, the odd occasions when this happened were sufficiently intrusive to what was an otherwise stellar performance that it made me go looking for a reason. Was it the speaker that was to blame, or once again, was I in danger of shooting the messenger?

This is what I found. The effect is a function of cables and driving electronics. I first noticed the problem with the otherwise impeccably well-mannered Rowland 625 stereo amp, driving a set of Nordost Odin speaker cables. Swapping the cables could mask the issue but didn’t eliminate it -- although it was just as clear that the high-frequency linearity and sheer treble energy of the Odins wasn’t necessarily doing the speaker any favors. At this point it would have been easy to conclude that the Blade was a superb speaker marred by a dodgy tweeter. It wouldn’t be the first and it won’t be the last. But swapping the driving amps to the VTL MB-450 IIIs eliminated the problem, whether the Odin was in use or not. Two possible explanations offered themselves: either the extra power of the '450s and the darned great lump of steel between their output devices and the tweeter made them more tolerant of some nastiness in the speaker’s high-frequency impedance curve, or the fact that they possibly don’t produce so much energy at high frequencies to excite the problem. Faced with this conundrum, there was nothing for it -- clearly the only solution was to obtain a pair of Rowland 725 monos to see if that solved the problem (well, that’s my story anyway -- and I’m sticking to it). Fortunately, for once intuition proved correct. Plugging in the 725s banished the issue completely, whilst simultaneously extending everything that makes the 625 one of my favorite amps. This was a marriage made in heaven and one I’ve been massively enjoying ever since.

So what are you to conclude from this? The Blade is a remarkable performer, but it hasn’t totally eschewed the honesty of its forebears. Its inherent coherence will ruthlessly expose any discontinuity in the driving system, whether that resides in the character of the electronics or is provoked by the demands of the signal. If an amp clips -- which is what I believe I was hearing -- the speakers let you know in no uncertain terms. The good news is that when it comes to self-preservation, that’s a bonus for your drive units and your ears. The speaker/amplifier interface is the single most critical junction in any system; the clean, uncluttered sound and expansive dynamics make it particularly critical with the Blade. Don’t buy these speakers without hearing them on your own amplifier and with your own discs. Be realistic about your listening levels and then push it some, just to be sure. At the Rocky Mountain Audio Fest last year, KEF drove the Blades with a quartet of Parasound Halo monoblocks. I’m not saying you need to go that far, but be aware that if your amplifier folds at the knees, the speakers are going to be pointing the finger and jeering.

The second conclusion you should draw from my experience is that this might be a $30,000 loudspeaker but you’d better treat it and feed it like it cost $60,000. The goods news is that if you do that, then it will sound like it cost $60,000 too. Striking, elegant and undeniably demanding, you’ve got to seriously antagonize the Blade before it would be so impolite as to respond. But pamper it properly and treat it the way you should, and it will draw admiring glances and beguile your guests. Eliza, it’s time to step out of the shadows.

Falling in love again

So much of the Blade’s presentation depends on the coherent nature of its driver disposition that there is no better place to start in terms of discussing its sound. Let’s start small: The Texas Campfire Tapes [Cooking Vinyl Cook002] was the album that introduced the world of Michelle Shocked to the world at large. Captured on a Sony Pro Walkman in the corner of an East Texas field, this simple voice-and-guitar recording is about as natural and unforced as you’ll ever get. Many a good system can reproduce the sense of space created by the open-air setting, helped by the crickets chirping in the background. Some can match the natural scale presented by the Blades, the physical presence and spacing of voice and guitar. But there are very, very few that reproduce the rock-solid rhythmic integrity that underpins these captivating performances. It’s all about the immediacy of the simple recording and the ability of the speaker to present everything where and when it should. This temporal accuracy is what so often separates the recorded from the live event. The effortless sense of rhythm that locks together the different parts of a band or song when you hear it live is all too often the first casualty of the reproduction process. If the recording doesn’t mangle it, the chances are that the speakers will. The wider the bandwidth, the greater the problem, as more drivers and more crossover get in the way of phase-coherent reproduction. But here we have a large speaker that not only scales its output to the performance in question, it delivers that music with such a natural rhythmic directness and tempo that it ceases even to be an issue -- until you realize just why you are enjoying it so much!

And don’t go thinking that just because you don’t listen to country-punk this doesn’t affect you. Play the CD of Coltrane’s My Favorite Things [Atlantic 7567-81346-2] and the rooted quality of that easy, rolling piano opening is immediately apparent, fresh and attractive. The cymbal work is subtle and perfectly placed, adding further points of reference to the rhythmic pattern, while Coltrane’s solo elongates and meanders without ever losing touch with the musical core played out by the rhythm section. There’s a holistic quality to the performance and music that belies the hard left/right separation of the stereo mix. Just for fun, I compared the CD with the mono LP [Atlantic 1361], and if ever you needed an argument for mono replay, this is it. The flexible brilliance of McCoy Tyner’s piano lines, the way they evolve and repeat, underpin and anchor Coltrane’s wandering second solo is a master class in ensemble playing, a whole that’s so much greater than the sum of its parts, that’s so much more whole on the mono than the stereo. This is about structural integrity, and the KEFs clearly reveal the sheer variation that exists, even between different versions of the same recording.

Move on to Beethoven’s 7th Symphony and compare the difference between the 1963 Karajan/BPO recording [DGG 463 088-2GB5] and the Haitink/LSO reading from 2006 [LSO 0598]. Listen to the second movement; the feel and mood of these two performances could not be more different, Karajan’s almost ponderous, funereal pace and weight, in stark contrast to Haitink’s pulsing sense of life and underlying power. That difference will be apparent on most systems, but it is the Blades that highlight not the difference in tempo but the difference in structure. Karajan’s baton dictates a smooth, continuous ebb and flow to the piece, tone and melody dictating its pace and passage. Haitink is more literal, the tempo and shape clearly defined by the bars in the score. It’s a fascinating insight into how and why performances work or provoke the emotional reactions they do -- and one that the KEFs effectively throw in for free. Whatever you play you’ll receive that same sense of structural and temporal connection.

Last, and by no means least, let’s consider a little bit of Elvis -- Costello, that is. Underrated in his early years as a purveyor of strikingly effective ballads, often with bite and edge that generally escape the genre, our Declan excelled himself on This Year’s Model [Demon Fiend 18]. "Little Triggers" involves more rhythmic hesitations and pregnant pauses than the first overtures at a high school prom -- and that’s just the point. The song is all about the angst and awkward reality of the biological imperative. Each anxious peak, each swooping deflation is mercilessly mapped and revealed by the Blades’ grip on pace and timing. The result is exactly the sort of emotional roller coaster the song portrays, right up to the last shudder of anticipation, that last surge of hope, waiting to be dashed.

But as apparent as this quality is on a track like "Little Triggers," that same rock-steady foundation underpins the whole album. So a song like "You Belong To Me" has exactly the same infectious energy and insistent beat that you’d enjoy live, and even the subterranean bass line on "Pump It Up" is propulsive and driven, rather than the stodgy mess that oozes out of most systems. Again, this is the sort of catchy pace and life that are normally the province of little two-ways, speakers that don’t go deep enough to get themselves into serious trouble. But here you are getting it from an ambitious three-way, complete with large cabinet and six drivers a side. That’s impressive.

One last observation before we move on. Just listen to the shape, weight and independence of the bass line on "Little Triggers." Not only are the notes clean and clear, perfectly placed and balanced against the rest of the band, their shape is gloriously, voluptuously rounded and real, burgeoning, swelling and then stopping dead as the string is damped. Next time you need an example of music as metaphor, look no further than this track and this speaker. You can almost picture the taught fabric and straining seams.

This ability to keep the structure and energy in the music intact is key to the Blades’ musical success. The mantra of "a place for everything and everything in its place" instills its own discipline, ensuring that each element in the musical mosaic retains its proper size and shape. It’s obvious on a disc like the Michelle Shocked, but it is also the quality that keeps orchestral soundstage perspectives natural, seamless and ultimately convincing. If the timps elbow the other instruments out of the way every time they get hit hard, it disturbs the fabric of the performance and rips aside the illusion. If those rents ever appear in the music played on the KEFs it is because of ham-fisted engineering in the studio, not the loudspeaker factory. In fact, what a combination like the Blades driven by the Rowland 725s really tells you is that many (particularly classical, particularly large-scale classical) recordings are better than we give them credit for. Let’s not get too carried away; modern pop papp that has been compressed to within an inch of its life still sounds like dreck, but beyond that, if there’s a performance buried in there somewhere, the Rowland/Blade combination will dig it out with all the energy and purpose of a musical Indiana Jones.

This spatial and temporal coherence also plays to the strengths of partnering electronics. The combination of the Blades with the Berning Quadrature Z monos was a tantalizing (even if ultimately slightly frustrating) experience, the speakers reveling in the sheer speed, transparency, organization and clarity of the amps -- right up to the point where that tweeter stepped forward to call "time" on the party. Smaller-scale works, well-recorded pop, small-group jazz all sounded breathtakingly present and immediate. The attack and tactile quality of the guitar on the Michelle Shocked record, the body and volume of her guitar and sheer sense of presence, are quite remarkable, the KEFs feeding off the microdynamic resolution and substance that come with the Connoisseur line and phono stages. Likewise, the solidity and purpose on This Year’s Model; played with the Connoisseurs and Bernings doing the driving, the quality of this recording and early pressing make you appreciate just why this was the golden age of UK rock and pop recordings.

Equally impressive, but in a very different way, the Clemencic Consort’s Danses de la Renaissance [Harmonia Mundi HM610] is another fantastic musical and recording tour de force from this established collaboration. The sense of space and precision, order and the height and air within the venue all add to the magic, but what really impresses is the way the unusual tone and textures of the original instruments, so different to their modern counterparts, are captured and preserved. This is dance music and, no matter how stately (and Rene Clemencic is not above a little ribaldry), it should make you want to dance. The Connoisseur/Berning/Blade combination has a compelling, almost insistent rhythmic urgency that makes bones and muscles move, almost of their own volition. As an aside, the amazing range of vibrant colors conjured by this disc should allay any fears as regards the KEFs’ tonal accomplishments. They may lack the exotic driver materials employed by the likes of Avalon, Focal or B&W, but they’re not alone in that and it doesn’t seem to hold them back.

The story is similar when it comes to jazz. Pick Birth of the Cool [Capitol F671045], a "Good Buy" 180-gram repressing, and the seamless geometry of rapidly interlocking parts is at once complex and clear. The blat of Miles’ trumpet is unmistakable, as is his quicksilver finger work, while Mulligan’s virtuoso outings on the baritone sax are wonderfully supple and sinuous. Note too the contrasting styles of Kai Winding and J.J. Johnson on trombone -- and the contrast between the agility of Miles’ valves and the smoother lines from the slide tuning. All these little details and characteristics bring the music and the people playing it to life. Ultimately, they’re what make a stereo system convince -- and what make it worth listening to. The stellar combination of Connoisseur and Quadrature Z -- the audio equivalent of Fred and Ginger -- might supply the insight, but it’s down to the Blades to deliver it.

But large-scale orchestral climaxes, whether Beethoven’s 9th, Elgar or Rachmaninov, whilst never less than joyously, enthusiastically energetic and musically committed lost the stability, focus and control that made more manageable material so compelling. If I could extend the Berning amps’ grip to the edge of this particular envelope I’d be happy indeed! As it is, living with the Blades and the Quadrature Zs in combination saw me leaning toward the subtle and sublime as opposed to the densely demanding end of the scale. Don’t misunderstand me here. You really do need to push the scale and level limits before the sonic picture starts to crack, but when a system sounds this good, any constraints leave you casting envious eyes at those areas that remain off limits.

Aside from a pickiness with partners that makes the average teenage princess seem like a model of compliance and accommodation, the KEFs’ other failing -- at least in absolute terms -- is a byproduct of what makes them so successful. That clean, linear and uncompressed bass is fabulous -- but it doesn’t reach down far enough to establish a really solid acoustic space, especially the boundaries of the recorded venue. Where a speaker like the Grande Utopia EM, the Isis or the Wilson XLF leave you in no doubt as to the nature, size and shape of the recorded acoustic, assuming there is one, the Blade sits nearer to (or just below) the likes of the Stella, Time or MAXX 3 in this respect. What that means is that you get the sense of air around instruments and orchestras, and you’ll hear the boundaries when they impact directly on an instrument, but you don’t have those boundaries as a constantly defined presence. So, if a percussionist rolls his timps or hits his bass drum, you’ll hear the wall behind him. But otherwise you won’t really be aware of it.

How much this matters to you will depend on the type of music you listen to and to some extent the age of the recordings. If you listen mainly to pop or jazz, I doubt you’ll even notice, unless you go looking specifically for the effect. I listen to a lot of large-scale classical, a lot of it recorded early in the stereo age, so, yes, I have a lot of discs with significant acoustic information on them. Does that stop me enjoying the KEFs? Not at all, for all the positive reasons outlined above. But it is one aspect of their performance that separates them from the genuine state-of-the-art speakers out there -- despite challenging many of them in so many other aspects of musical reproduction and communication. The upside is that, as noted earlier, you don’t suffer an ersatz acoustic, imposed by the physical dimensions of the listening room -- and the more I get used to that, the more I like it. Occasionally I find myself musing on what I term the age-old electrostatic conundrum: limited bandwidth -- even on a model like MartinLogan’s amazing CLX -- leaves one tempted by the notion of adding a decent subwoofer to the system. The question is, by doing so, will you be throwing out the musical baby with the bandwidth bath water? Will you destroy the very thing that makes what you already have so special in the first place? So, yet another parallel betwixt the Blade and the ESL63. I don’t know the answer to the question, but I do know that I’d like to find out!

Tying the knot

The KEF Blade is a remarkable achievement by any measure. Genuinely innovative in terms of materials and engineering, its success rests in no small part on the solid foundation underpinning its family tree. It may not look too much like its brethren, but form and function both trace a clear line of descent from those earlier models. I’ve spent a lot of time discussing the engineering elements of this speaker, but what really makes them work is their collective maturity, the overall balance of capability spread across the design as a whole -- a whole that is impressively superior to the sum of its parts.

Musically communicative in a way that few speakers can match at any price, the KEFs are also sonically adaptable. They don’t impose their own stamp on the system or the music, but rather, like various Avalons, they have that trick of revealing and reveling in the characteristics of the driving electronics. That’s a very good thing if the system is well chosen and well sorted; just don’t expect them to paper over the cracks. In this case, if you shoot the messenger you are missing a genuine opportunity.

The KEFs’ striking appearance is something of a double-edged sword. There will be those who dismiss them as a novelty product. That would be a big mistake -- huge, in fact! The KEFs look the way they do for clearly stated and easily appreciated reasons. They represent excellent material value for money (just list what goes into them and do the same for other, similarly priced designs) and an even bigger sonic bargain. They deserve the widest possible audience and the most serious consideration.

No product is universal in its appeal. You simply can’t please all of the people all of the time and nor should you expect to. I believe that the KEF Blades are an important speaker, not just because I admire their sonic and musical achievements. To me, their combination of fit, finish and achievable performance represent exactly the sort of products not just that this industry should be making but that it must make if it wants to survive. A stunning indication of what happens when serious investment meets solid engineering and nobody applies the brakes on ambition, the KEF Blades present one of the most enjoyable and downright uplifting hi-fi experiences I have had in quite a while. I love what they do on a musical level and I love how they do it. But by making this level of performance, if not exactly affordable then significantly more attainable and more widely acceptable (from a domestic/visual perspective) they have instilled a real sense of optimism -- at least in this house. There’s a pair of KEF’s almost prosaically normal-looking R900s lurking in my storeroom. I wonder, I just wonder. . . .

Price: $30,000 per pair; $32,000 per pair in optional finishes.
Warranty: Five years parts and labor.

GP Acoustics (HK) Ltd
6/F Gold Peak Building
30 Kwai Wing Rd
Kwai Chung, Hong Kong
www.kef.com

Associated Equipment

Analog: VPI Classic 4 turntable, Lyra Titan i, Skala, Dorian and Dorian Mono; Clearaudio Goldfinger Statement; van den Hul Condor; Allnic Puritas and Puritas Mono cartridges, Connoisseur 4.2 and Allnic H-3000V phono stages.

Digital: Wadia S7i CD player. dCS Paganini transport, DAC and uClock, Jeff Rowland Aeris DAC, Wadax Pre 1 digital control unit.

Preamplifiers: Lyra Connoisseur 4.2L SE, VTL TL-7.5 Reference Series III.

Power amplifiers: Berning Quadrature Z monoblocks, Jeff Rowland 625 stereo and 725 mono amplifiers, VTL MB-450 Signature Series III monoblocks.

Loudspeakers: Coincident Speaker Technology Pure Reference Extreme.

Cables and power products: Complete looms of Nordost Odin or Crystal Cable Ultra from AC socket to speaker terminals. Power distribution was via Quantum QB8s or Crystal Cable Power Strip Diamonds, with a mix of Quantum QX2 and QX4 Power Purifiers and QV2 AC Harmonizers.

Supports: Racks are finite elemente HD-04 Master Reference racks and amp stands along with a 26"-wide Stillpoints ESS. These are used with equipment couplers throughout, either Stillponts Ultra SS's or Nordost SortKones. Cables are elevated on Ayre myrtle-wood blocks.

Accessories: Essential accessories include the Feickert protractor and Aestetix 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.

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