Most-Read Reviews (Last 5 Years)
- 2013-04-15 - KEF LS50 Loudspeakers
- 2012-08-01 - KEF R500 Loudspeakers
- 2011-02-01 - Bowers & Wilkins 803 Diamond Loudspeakers
- 2014-12-15 - KEF Reference 1 Loudspeakers
- 2010-10-01 - Bowers & Wilkins CM5 Loudspeakers
- 2013-09-01 - Tannoy Definition DC10A Loudspeakers
- 2012-03-01 - Monitor Audio Gold GX100 Loudspeakers
- 2011-09-15 - Paradigm Atom Monitor v.7 Loudspeakers
- 2011-12-15 - Eximus DP1 Digital-to-Analog Converter/Preamplifier/Headphone Amplifier
- 2014-12-01 - Sonus Faber Olympica III Loudspeakers
Most-Read Reviews (Last 365 Days)
- 2017-04-01 - KEF Reference 3 Loudspeakers
- 2016-08-01 - T+A Elektroakustik PA 2000 R Integrated Amplifier
- 2016-11-15 - Moon by Simaudio Neo ACE Integrated Amplifier-DAC-Streamer
- 2016-07-01 - Bryston BDA-3 Digital-to-Analog Converter
- 2016-07-15 - Moon by Simaudio Neo 330A Stereo/Mono Amplifier
- 2017-01-01 - Hegel Music Systems Mohican CD Player
- 2017-04-15 - MartinLogan Masterpiece Classic ESL 9 Loudspeakers
- 2016-12-15 - PS Audio BHK Signature Preamplifier
- 2016-10-01 - PS Audio PerfectWave DirectStream Junior Digital-to-Analog Converter
- 2017-03-01 - Audio Research Foundation LS28 Preamplifier
Most-Read Reviews (Last 90 Days)
- 2017-04-01 - KEF Reference 3 Loudspeakers
- 2017-04-15 - MartinLogan Masterpiece Classic ESL 9 Loudspeakers
- 2017-05-15 - Devialet Expert 130 Pro DAC-Integrated Amplifier
- 2017-06-01 - Bryston 4B3 Stereo/Mono Amplifier
- 2017-05-01 - Ayre Acoustics QX-5 Twenty Digital-to-Analog Converter
- 2017-06-15 - Markaudio-Sota Viotti One Loudspeakers
- Written by Doug Schneider Doug Schneider
- Category: Full-Length Equipment Reviews Full-Length Equipment Reviews
- Created: 15 April 2016 15 April 2016
Note: Measurements taken in the anechoic chamber at Canada's National Research Council can be found through this link.
In 2009, when KEF unveiled the Concept Blade at High End, in Munich, Germany, its radical shape was a bolt from the blue that left little doubt that KEF wanted to make a statement -- that they were on the cutting edge, so to speak, of loudspeaker design, in terms of both looks and sound. I was gobsmacked by the speaker’s visual beauty, particularly its similarity to a knife blade when viewed from the side.
Two things about the Concept Blade’s acoustical engineering stood out. First, it was clear that the designers were making more than a visual statement with that narrow, curved front baffle: they wanted to give the speaker’s front-mounted Uni-Q driver -- a coaxial design comprising a tweeter and a midrange (described in more detail below) -- a noninterfering platform from which to launch soundwaves. Second, the Concept Blade’s four woofers were mounted two on each side, all equidistant from the Uni-Q. It was obvious that KEF’s designers were attempting to create point-source behavior throughout the audioband -- in other words, a uniform soundfield created by the outputs of all the drivers seeming to originate from a single point in space.
The Concept Blade was just that -- a concept, a prototype, not a production model. However, KEF was sufficiently encouraged by the positive reaction of the public and the audio press that, under the direction of Dr. Jack O’Clee-Brown, KEF’s acoustics team found ways to reduce the prototype’s cost and complexity to the point where it became a commercially viable product that could be manufactured in the UK, at KEF’s factory. The Blade was launched in 2011; it’s still available, for $31,999.99 USD per pair. Three years later came the subject of this review: the Blade Two ($24,999.99/pair).
Take snapshots of the Blade and Blade Two on their own and you might not be able to tell them apart -- the cabinet shapes are the same, as are the placements of the drivers. The Two is just a bit smaller. The finish options, too, are identical: Snow White and Piano Black are standard; Racing Red, Light Metallic Silver, Warm Metallic, Frosted Copper Black, and Frosted Blue are optional, and usually take longer for delivery, at least in North America.
The Uni-Q driver is the same in both Blades, but differs from those used in KEF’s Reference and R-series speakers, though all of these look almost identical. This coaxial driver comprises a 1” aluminum-dome tweeter buried in the throat of a midrange driver whose 4” cone is made of an alloy of lithium, aluminum, and magnesium. The tweeter and midrange motor systems have neodymium magnets, which can generate a much stronger magnetic force than can ferrite magnets of the same size, provided all else is equal. The midrange cone has a 3”-diameter voice coil, and liquid-crystal polymer (LCP) ribs on its rear surface. LCP is said to be exceptionally strong and remarkably inert, so these ribs stay rigid under extreme conditions. Because of its extra-large size, the voice coil is attached closer to the edge of the cone than to its center, a configuration KEF calls “nodal drive.” The positioning of the coil, the inclusion of the LCP ribs, and the cone’s shape (which KEF’s engineers arrived at through computer modeling) and materials combine to keep this driver’s motion pistonic throughout and well beyond its operating bandwidth. This means that, as the cone reproduces the frequencies it’s told to, it retains its shape, instead of bending and flexing like many diaphragms, which can create audible distortions. According to O’Clee-Brown, the midrange driver’s operating bandwidth is roughly between 380Hz and 3kHz, the frequencies at which it’s respectively crossed over to the woofers and the tweeter.
The upper limit of the audioband -- that is, the top of the range of human hearing -- is generally considered to be 20kHz. KEF claims that the aluminum-dome tweeter used in both Blades remains pistonic past 40kHz -- not only far beyond the audioband, but, surprisingly, higher than even many beryllium-based domes I’ve seen measured can go without hitting their natural resonance points. (Although beryllium domes can be made to extend well past 40kHz without breakup, many I’ve seen measured go only a little past 30kHz.) According to O’Clee-Brown, achieving such a high breakup point has partly to do with the materials used in the tweeter, but mostly with the dome’s shape.
I need to say a bit more about the Uni-Q, because it’s such an important element in KEF’s current speaker designs. Burying the tweeter in the midrange cone aligns the acoustic centers of both drivers at the same point in space, which means their sounds propagate along the same axis. As a result, the summing behavior of their soundwaves as they radiate from the speaker is consistent at all points above and around the speaker. This is quite different from most speakers’ driver arrays, in which the tweeter and midrange are usually at least a couple inches apart. The summing behavior of disparate drivers positioned so far apart changes as you move to different places around the speaker, because the distances from each driver to those places are constantly changing. Imagine attaching ends of two strings of equal length to the center of each of two separate (i.e., non-coaxial) drivers, but holding the other ends together so that they line up perfectly where they terminate. It will form something like a triangle, because the driver ends are apart. Then, move that ending point to where both strings meet around in space -- each string will move differently wherever you move, because each is attached to a driver that’s in a different place from the other driver. If you attach those same strings to the center of the Uni-Q’s midrange and tweeter, they’ll be attached to the exact same spot at the speaker end, because the center of the midrange is also the center of the tweeter. As a result, the strings will remain together as you move the ending point of the strings around.
The midrange cone is also shaped to act as a waveguide for the tweeter; that is, it controls or redirects the propagation of the tweeter’s soundwaves, to better match the tweeter’s dispersion characteristics with that of the midrange. The waveguide also provides the tweeter with acoustical gain -- exactly how much depends on the frequency. For example, imagine speaking into a megaphone: it amplifies your voice. The waveguide works similarly, although the secret of good waveguide design is to shape it to avoid stereotypical horn-type colorations. To give me an idea of just how much gain can be generated by a waveguide, O’Clee-Brown sent along charts that show that the Blade Two’s midrange cone provides up to 7dB of gain for the tweeter at about 4kHz, that gain diminishing at a very slow but constant rate for higher and lower frequencies, until, at about 1kHz and 10kHz, it provides no gain at all. And 7dB is a lot of gain: It takes double the amount of amplifier power to increase a speaker’s output by 3dB, and twice that power again to achieve another 3dB rise in volume level, and so on. KEF’s waveguide provides up to 7dB more output without the amplifier having to work a bit harder.
However, the midrange cone doesn’t affect the tweeter’s output above 10kHz, because the wavelengths of those higher frequencies are so much shorter. Enter KEF’s “tangerine waveguide,” consisting of the nine fin-like things in front of the tweeter attached to the midrange cone. Again according to O’Clee-Brown’s graphs, the tangerine provides some 3dB of gain centered at about 15kHz, and helps control the tweeter’s output when the dome hits its natural resonance point somewhere above 40kHz. Clever.
But there are differences between the Blade and the Blade Two -- most notably, in the sizes of their cabinets and woofers, and in the components of the crossover, to accommodate the differing drivers.
According to KEF’s specs, the Blade’s cabinet, with plinth, measures 62.5”H x 14.3”W x 21.2”D; the Two’s cabinet, with plinth, is 57.5”H x 13.3”W x 18.7”D. That might not seem much of a difference, but if you look at the speakers side by side, it’s easy to see that the Blade Two is quite a bit smaller. However, those dimensions make both speakers sound a bit wider on paper than they actually appear -- the width cited is that of the plinth, which is only 1 5/8” high (without spikes). Once you get past the plinth, the Blade Two is only about 7.5” at its widest and 18” at its deepest -- it doesn’t take up much space. And despite it’s being nearly 5’ tall, the Blade Two is lighter than it looks -- just 78 pounds -- which made unboxing it and moving it around easy. The reason it’s so light is that it’s made from what designer and engineer Phil Gidley describes in our SoundStage! InSight Blade Two video as a “self-forming composite,” which doesn’t weigh nearly as much as the woods and metals most other speakers are made of.
The Blade Two’s four side-mounted aluminum-cone woofers are a lot smaller than the Blade’s quartet: 6.5” vs. 9”. This means that, all else being equal, the Two’s woofers can’t move as much air, which, in turn, means less bass extension and output. Each pair of opposed woofers is bolted to the cabinet, and the two woofers are connected to each other inside the speaker with metal rods, in what’s called a force-canceling configuration. The cabinet interior is subdivided: each woofer pair operates within its own subenclosure, with its own port on the rear panel.
Force-canceling woofers aren’t unique to KEF, but few companies use the technique, despite its obvious advantages: Extraneous vibrations created by each woofer are canceled because, when both are pumping out bass, their movements are equal and opposite of each other. As a result, vibrations from each driver that would normally travel into the cabinet are almost completely eliminated, which is one of the reasons KEF’s designers could get away with using such a lightweight cabinet material -- there’s less need for damping unwanted resonances with extra mass. Vivid Audio does the same thing -- I also had in for review Vivid’s Oval B1 Decade speaker ($28,000/pair), which has opposed woofers. (Vivid’s designer, Laurence Dickie, does a great job of explaining force-canceling drivers in a SoundStage! InSight video we produced in October 2014.) The efficacy of this approach became clear to me when I played bass-heavy music loud: When I laid a hand on the Blade Twos’ cabinets, I felt as little vibration as I’ve felt from speakers two or three times the Two’s weight. It works.
My only complaint about the Blade Two’s lightweight construction has to do mostly with the plinth, which is light plastic and looks it. The heavy drivers are mounted high on the speaker, which makes the Two a touch top-heavy, even with the supplied floor spikes screwed in. The spikes raise the speaker a bit, but make it far more stable on carpeted floors. Neither speaker fell over during the listening period, but once, when changing speaker cables, I bumped a Two hard with my butt -- it rocked back and forth enough that I was very glad I hadn’t bumped it harder.
Toward the bottom of the Two’s rear panel are two pairs of binding posts: the top two are connected to the tweeter and midrange, the bottom two to the woofers. These can be used for biwiring or biamping, provided you turn fully counterclockwise the two knobs labeled Link, which are between the posts. If, as I did, you use only a single pair of speaker cables, turn the Link knobs clockwise to connect the leads of the top and bottom posts.
The two Blades’ impedances are specified the same: 4 ohms nominal, 3.2 ohms minimum, which should be an easy enough load for most amps. The Two’s sensitivity is a claimed 90dB vs. the original Blade’s 91dB (both at 2.83V/m), which likely won’t make a bit of difference, regardless of the amp used. The Two’s maximum output, measured as a peak level using pink noise, is specified by KEF as 116dB, the Blade’s as 117dB -- again, a negligible difference, and anyway, few people would ever dream of playing their speakers that loud.
The biggest difference is in the bass-extension specs. KEF rates the Blade’s “free field” and “typical in room” bass responses as, respectively, 28 and 20Hz, both -6dB. The Blade Two’s corresponding specs are 34 and 25Hz, both -6dB. Those differences are not trivial -- the Blade goes considerably deeper than the Blade Two. But which Blade will sound better will mostly depend on the room it’s used in -- some rooms don’t deal well with superdeep bass, others do. Furthermore, despite the Blade Two’s less extended bass, as you’ll read below, the “Baby Blade” (as KEF’s Johan Coorg called it in our video) could hardly be called bass-shy.
System and setup
Because my reviews of the Vivid Oval B1 Decade (B1D for short) and KEF Blade Two overlapped, most of the equipment I used for each was the same, which helped with comparisons. I mostly drove the Blade Twos with my Blue Circle Audio BC204 stereo amplifier (150Wpc into 8 ohms or 250Wpc into 4 ohms), which has a tubed input stage and a solid-state output stage. But for a short while I also used JE Audio’s all-tube VM60 monoblocks, specced at 60W each into 8 or 4 ohms. The VM60s lacked the power to play the Twos superloud, but they do have some magical properties in the midrange that the Vivids and KEFs readily revealed (see below). Ahead of the amps were Simaudio’s Moon Evolution 740P preamplifier with optional Moon Evolution 820S power supply; Hegel Music Systems’ HD30 DAC, which I reviewed in December 2015; and a Samsung laptop computer running Windows 10, JRiver Media Center 20, and the Tidal music-streaming service.
I connected DAC to computer with an AudioQuest Carbon USB cable and JitterBug USB filter, the latter connected to the computer’s USB port. I used Crystal Cable Standard Diamond interconnects and Siltech Classic Anniversary 330L speaker cables for all analog signals. The electronics were plugged into one of two Shunyata Research Venom PS8 power distributors (one for the source components, the other for the amps). Plugged into one receptacle of each PS8 was a Shunyata Venom Defender noise reducer/EMI suppressor. Shunyata Venom HC power cables were used for the preamp and DAC, stock cords for the power amps.
After experimenting with placement, I wound up setting up the Blade Twos the same as I had the B1Ds because that’s where they sounded best: just over 8’ apart, tweeter to tweeter, and 8’ from my listening position, firing straight (no toe-in).
I cued up “Mining for Gold,” from the Cowboy Junkies’ The Trinity Session (16-bit/44.1kHz FLAC, RCA) -- probably the album I most often play for reviews nowadays, because I know it so well -- and marveled at the hugeness of the soundstage, the overall clarity and neutrality of the sound, how well focused Margo Timmins’s voice was at center stage, and the breathtaking depth of the bass. But it was with the Junkies’ cover of the Velvet Underground’s “Sweet Jane” that I was able to zero in on the Twos’ unique abilities in soundstaging and imaging. In this track, Timmins is at center stage, the lead guitar to the left, just a little behind her, and the drums to the right, much farther back. Most well-set-up speakers likewise put Timmins’s voice very solidly at center stage, and position the other instruments in the correct locations, but none I’ve reviewed has positioned the other instruments as solidly and tangibly as the Twos did -- we’re talking hyperprecise toward the sides of the stage. Furthermore, even though the drums were very far back and to the right, their aural images were as precisely drawn as that of Timmins’s voice up front and center. I haven’t heard any other pair of speakers achieve that degree of image focus across the stage with all of the instruments in this track.
In the next track, “Postcard Blues,” Steve Shearer’s harmonica is at right, and the Twos positioned it with as much focus and tangibility as Timmins’s voice at center stage. Again, the effect was uncanny -- with pretty much every other speaker I’ve heard, the imaging to the side gets a little vague, even though the positioning is correct. But with the Twos, it was not only more vividly drawn, the illusion of depth was far more convincing than I’d heard before.
Intrigued by how precisely the Blade Twos were placing images left to right and front to back on the soundstage, I played “Mademoiselle Mabry,” from Miles Davis’s The Complete In a Silent Way Sessions (16/44.1 FLAC, Columbia/Legacy/Tidal). Davis’s trumpet is at center stage, but the other instruments are hard right and left, which makes for a very wide but not very realistic-sounding stage, particularly with the drums way out to the right. That kind of left/right spread tends to draw the listener’s attention to the speakers themselves, rather than to the music. But with the Blade Twos imaging so accurately in my room, and able to “disappear” into the soundstage and convey such convincing depth with such precision and focus, even with images placed at the extreme sides of the stage, I found that this 1968 recording sounded quite a bit more natural -- I was better able to imagine the instruments being set farther back and detached from the speakers, not right at them.
I also played “Everest,” from Ani DiFranco’s Up Up Up Up Up Up (16/44.1 FLAC, Righteous Babe), a recording I often use for imaging because DiFranco’s voice and guitar aren’t at the front of the stage but to the left, and, based on what I’ve gathered from all the systems I’ve listened to this track through, a few feet back. (Of course, I wasn’t there for the recording or mixing, so I can’t know for sure, but after hundreds of listening sessions, I’m confident enough.) Through some of the best speakers I’ve heard, DiFranco’s voice and guitar are positioned specifically to the left, with a very good semblance of how far back she’s positioned. But with the Blade Twos, her positioning was laser-like -- her voice and guitar sounded as if emanating from a spot exactly 3’ behind the left speaker’s Uni-Q driver. That spot was about 3” above the upper port, or midway between the woofers on each side.
In this album’s title track, DiFranco’s voice is mixed at center, a placement the Twos re-created as a focused point in space about the size of a softball. Her voice sounded remarkably clear and natural, indicating to me that the Blade Twos were adding no colorations of their own. But what really took me aback was when, 2:03 into the song, the drums came crashing in -- with greater weight, impact, and solidity through the Twos than I’d ever heard in my room. This was startling because the Two is the “Baby Blade,” with more limited bass reproduction than the full-grown Blade. Nonetheless, the Two sounded anything but small, and while it might output less bass than its big brother, it delivered far deeper bass than Magico’s S5s ($29,500/pair) had in my room, or Vivid’s Oval B1 Decades (more below). Based on what I heard, KEF’s in-room rating of 25Hz is probably true.
But because the Blade Two sounded so powerful in the bass, I wanted to make sure that none of that bass was overblown -- an inflation of reality. That’s what had happened with the Polymer Audio Research MKS ($42,000/pair), whose sound, though really big down low, was a little too prominent and a touch loose, at times even sounding fat. To hear if KEF had got the Two’s bass voicing right, I turned to the title track of Adam Cohen’s We Go Home (16/44.1 FLAC, Rezolute Music), which has tremendous WHOMP when the kick drum enters. I wasn’t in the studio when this album was recorded either, but I’ve heard Cohen perform live in a small, well-designed theater with good acoustics. The same drummer was playing as had played on the album, and the engineer kept the SPLs reasonable -- rare in live venues, where everything is usually so loud you risk hearing damage. The overall bass level at the concert closely matched what I heard in my room: prominent when the drums entered, but not so much as to obscure the other musicians.
I went back and listened more carefully to the Cowboy Junkies’ “Mining for Gold.” I’ve found with this track that if a speaker’s bass is too elevated, it overshadows Margo Timmins’s voice. Through the Blade Twos, the substantial bass weight was obvious -- it thundered in my room -- but with no overshadowing or loss of clarity in the singer’s voice. I can only surmise that the powerful bass the Blade Twos presented accurately reflected what the recordings contained.
Listening to these and many other tracks revealed other Blade Two strengths. I mentioned the clarity I heard with the Cowboy Junkies and Ani DiFranco discs -- it conveyed fantastic purity and cleanness throughout the audioband, whether the volume level was whisper quiet or wall-flexing loud. That clarity, combined with the outstanding imaging, made voices, male or female, “pop” holographically on the soundstage.
My favorite song on We Go Home is “Song of Me and You.” Through the Blue Circle BC204 amplifier, Cohen’s voice was appropriately rich and highly detailed. When I replaced the BC204 with the JE Audio VM60 monoblocks, I heard a slight reduction in the lowest bass produced -- a typical byproduct of low- and medium-powered tube amps, which tend to lack extension at the audioband extremes -- but his voice was even richer and even more present than before. This I really liked, because it made the sound more palpable, full, and realistic. I also found that the VM60s sweetened the highs just a touch, which some might welcome -- the Blade Two, like other KEF speakers I’ve reviewed in my room and heard at shows, has highs that are extremely extended, voiced just this side of bright. A little sweetening up top can go a long way toward making inherently bright-sounding recordings just a little more palatable -- this speaker hides nothing, and holds no frequencies back.
With such a clean, neutral, near-full-range sound at both very low and very high volumes, the Blade Two was a sort of chameleon -- its sound depended on the type of music I threw at it, regardless of listening level. For example, for much of the time I spent writing this review, I streamed Miles Davis’s ’Round About Midnight (16/44.1 FLAC, Columbia/Legacy/Tidal) at very low volumes so that I could concentrate on my writing. Nonetheless, again and again I found myself looking up, marveling at how much detail I could hear, and how deep into the soundstage of this 1957 mono recording I could perceive.
At other times I cut loose with stuff that begs to be played really loud: orchestral music, metal, and hard rock -- particularly, when I felt like reliving my youth, rock from the late 1970s and early ’80s. Music like that just doesn’t seem right when played quietly (which is why guys at parties always yell “Turn it up!” when their favorite old song comes on). I also often played recordings that I don’t always feel compelled to play super loud -- but I did through the Blade Twos because the speakers never sounded as if they were straining. I played all of We Go Home many times at levels as loud, and sometimes louder, than those I heard at that Adam Cohen concert. Katarina and Svante Henryson’s High, Low or In Between, featuring just voice and cello (24/96 FLAC, BIS), is something I often use for background listening. But I cranked up their cover of the Beatles’ “Here Comes the Sun” to ridiculously loud listening levels -- beyond lifelike, I believe -- and was amazed that the sound remained as clear and composed as it was when played at reasonable or very quiet levels.
One of the hallmarks of a great loudspeaker is that it favors no kind of music over any other. The Blade Two easily achieved that -- and did so at any volume level.
Pit almost any current loudspeaker against Vivid Audio’s Oval B1 Decade and there’s a good chance it will come up short. Except for the B1D’s inability to reproduce with any authority the very lowest audible octave (20-40Hz), it sounds nothing short of exceptional throughout the rest of the audioband, with reference-class clarity, total transparency, and an openness of sound matched by no other speaker I’ve heard. KEF’s Blade Two is one of the few that can hold its own against the B1D -- and, in some areas, outperform it.
Before I get to the sound, it’s important to point out some design similarities between the Vivid and the KEF: both have force-canceling woofers; both have cabinets of radically different shape from the norm, and from each other, and made of unusual materials (the B1D’s cabinet comprises panels of vacuum-infused, fiberglass-reinforced resin sandwiching a balsa core); and both have bespoke drivers designed to retain their pistonic action within their operating bandwidths (like the Blade Two’s tweeter, the breakup frequency of the B1D’s aluminum-dome tweeter is beyond 40kHz).
When it came to depth of bass, and power throughout the bass range, the B1D’s two woofers were no match for the Blade Two’s four woofers in a much larger cabinet -- the Twos reached down to under 30Hz in my room with tremendous authority, whereas by around 40Hz the B1Ds had fallen off the cliff. The Blade Twos could also play at least a bit louder overall. At unrealistically loud listening levels, I did reach the B1 Decades’ limit: some compression in the highs set in (as I increased the volume, the bass and midrange frequencies were rising in level, but the highs were not); however, with the Blade Twos, I never found a place to stop. The only thing that stopped me was that I didn’t want to drive my amplifier into clipping. Overall, the Blade Twos sounded bigger, fuller, richer, and, when needed, louder than the B1Ds. Because of all that, a pair of Blade Twos would be my choice for a very large room.
The midranges of the Blade Two and B1D were comparable: exceptionally clear, unflinchingly neutral, amazingly detailed. The highs were equally extended and clean, but, in back-to-back comparisons, I found the B1D’s top end just a touch cleaner, as I stated in my review of that speaker: “I’ll say that the B1D’s top end was the cleanest I’ve heard -- ever.”
Where the B1D stepped ahead of the Blade Two was in the integration of the lowest part of the midrange with the upper bass -- something I hadn’t noticed was a problem with the Blade Two until I directly compared the speakers. Whereas the B1D provided a seamless transition from the midrange through the bass -- it was impossible to know where one driver kicked in and the other rolled off -- I noticed a slight reduction in openness and clarity in the upper bass and lower midrange with the Two, indicating a not quite seamless blend. This was particularly audible with certain recordings of male voices, something I first noticed when listening to “The Road,” from the high-resolution version of Jackson Browne’s Running on Empty (24/192 FLAC, Asylum). When the song transitions from Room 301 of the Cross Keys Inn to a concert at the Garden State Arts Center, in Holmdel, New Jersey, Browne’s voice suddenly sounds deeper and more resonant -- and it was here that the Blade Twos added a little bit of chestiness and congestion that the Vivid B1Ds didn’t. Recent Leonard Cohen recordings, such as Popular Problems (24/96 WAV, Columbia), highlighted the same thing, likely because Cohen’s deep, rich voice falls smack dab where the operating bandwidths of the woofers and midrange overlap. It’s also possible that because the Two didn’t sound as clear and open through this range, I found the B1D the more resolving speaker overall -- it seemed to reveal more throughout the audioband.
There were subtle differences between the speakers in soundstaging and imaging, but no clear winner. The B1Ds cast the most spacious soundstages that any front-firing speakers have in my room, with imaging that was always precise throughout the stage. The Blade Twos’ stages weren’t quite as spacious, but were darn close; however, the Twos’ images were even more tangible and focused, particularly toward the sides of the stage. Also, when musicians were layered in depth, their exact positions were easier to pinpoint through the KEFs. I found my preference switching back and forth between the KEFs and the Vivids, depending on the recording.
Soundstaging and imaging? A draw.
When KEF introduced their new Reference line at High End 2015, in Munich, I was surprised -- their rectilinear cabinets looked so ordinary compared to what they’d done with the Blades. When I asked Johan Coorg about this, he explained that although the Blades were big hits around the world, their knifelike profiles were too out there for some people. The Reference models were KEF’s way of offering something more traditional. I get that -- but I loved how the Blade Twos looked in my room. I also loved their sound.
KEF’s Blade Two ranks with Vivid Audio’s Oval B1 Decade -- which, except for the absence of the bottommost octave of bass, is one of the best-sounding speakers you can buy. That’s fine company. In comparison, the Blade Two gave way to the B1D in terms of clarity and cohesiveness in the lower midrange and upper bass, and wasn’t quite the epitome of high-frequency cleanness that the B1D was in my room. However, the Two handily bettered the B1D in bass power and extension. The Blade Twos also edged out the B1Ds in image specificity, particularly along the edges of the soundstage. And although the output levels either speaker is capable of exceed the needs of most listeners, the Twos could play a little louder in my large room. Add to those qualities strict neutrality across the audioband, extremely extended highs, and clarity that made me stand up and notice, and the Blade Two is a top-drawer transducer as exciting to listen to as it is to look at. There’s nothing in the world like the Blade Two -- except its big brother, the Blade.
. . . Doug Schneider
- Speakers -- Vivid Audio Oval B1 Decade
- Preamplifier -- Simaudio Moon Evolution 740P and Moon Evolution 820S power supply
- Power amplifiers -- Blue Circle Audio BC204, JE Audio VM60 (monoblocks)
- Digital-to-analog converter -- Hegel Music Systems HD30
- Computer -- Samsung laptop running Windows 10 and JRiver Media Center 20
- Digital interconnect -- AudioQuest Carbon USB
- Analog interconnects -- Crystal Cable CrystalConnect Standard Diamond
- Speaker cables -- Siltech Classic Anniversary 330L
- Power cords -- Shunyata Research Venom HC
- Power distributor/conditioner -- Shunyata Research Venom PS8 with Defender (2)
- USB filter -- AudioQuest JitterBug
KEF Blade Two Loudspeakers
Price: $24,999.99 USD per pair.
Warranty: Five years parts and labor.
Eccleston Road, Tovil
England ME15 6QP
Phone: +44 (0)1622-672261
Fax: +44 (0)1622-750653
GP Acoustics (US) Ltd.
10 Timber Lane
Marlboro, NJ 07746
Phone: (732) 683-2356
Fax: (732) 683-2358