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Estelon X Diamond Loudspeaker

Estelon X Diamond Loudspeaker

Here’s the thing about the ceramic-driver loudspeakers I’ve reviewed in the past. At low-to-moderate SPLs or on music performed pianissimo-to-mezzoforte, they have always been marvelous at reproducing the fine detail that tells you which instruments are playing, how they are being played, what hall or venue they are playing in (and where the musicians are seated in that hall), and how well or how poorly they have been recorded. In other words, céramiques are capable of electrostatic-like resolution precisely where electrostats themselves shine: at low-to-moderate volumes. This may not seem like much of an accomplishment if you’re used to listening to large-scale classical, jazz, or rock ’n’ roll at thunderous levels. But, trust me, there aren’t many other speakers that can do the relatively soft side with realistic softness without a significant loss of musical/ performance details. Almost all non-ceramic cones and all planars have to be kicked up a notch or two to resolve the low-level stuff with something approaching this same transparency, resolution, and realism, and, of course, kicking up the volume to hear soft passages more clearly ipso facto turns pianissimos into pianos thereby compressing dynamic range on the soft side (and making loud passages louder than they should be).

At low-to-moderate SPLs, ceramic-driver loudspeakers have another important virtue. They are extremely neutral and linear. Once again like some (not all) electrostats, they add less significant “color” of their own to instruments and the space they are playing in than other cone speakers, making for a soundfield that doesn’t sound “black.” (I’ve never really understood the use of that word as a commendation in this context, or of the words “grey” or “white.” I will come back to this point, however, in a moment.) At low-to-moderate playback volumes céramiques can approach the colorlessness and transparency of glass (or air).

Now here’s the rub: Music isn’t just played pianissimo to mezzoforte or meant to be played at such relatively low levels. Turn up the volume sufficiently (i.e., 85–90+dB average SPLs) and the virtues of ceramic-driver loudspeakers become considerably less virtuous. Their neutrality, which I just praised, can turn into a leanness and brightness that rob instruments of natural weight, power, and tone color. What seems to be happening here is oldfashioned ringing (break-up modes that cause audible distortion and compression as the diaphgrams are progressively stressed), induced in part by the fact that ceramic cones, while paragons of pistonic motion in their passbands, lack the self-damping qualities of cones made of different sandwiched materials (such as carbon-fiber and Rohacell). Indeed, it is my understanding that this ringing was why Accuton (the maker of virtually all ceramic cones) started putting those little laser-cut holes in its drivers, to provide some venting of the backwave to reduce out-of-passband (and in-passband) ringing, distortion, and compression on large diaphragm excursions.

But what if I was to tell you that, just lately, I’ve heard a ceramic-driver loudspeaker that solves or greatly ameliorates the high-SLP/large-scale-dynamics problem that—only a few years ago—was an inevitable part and parcel of the céramique experience?

Well, meet the Estelon X Diamond—a gorgeous, four-and-a-half-foot tall, three-way, quasi-hour-glass-shaped, ceramic-driver floorstander from that hotbed of loudspeaker technology and manufacture, Tallinn, Estonia.

To be honest, prior to the arrival of the Estelon X Diamonds, world-class loudspeakers were not the first things that came to mind when I thought of Tallinn, Estonia. This is in large part due to the fact that, prior to the arrival of the Estelons, there was no first thing that came to mind when I thought of Tallinn, Estonia. But surprise, surprise! Turns out brilliant audio engineering isn’t confined to the usual suspects in Great Britain, Western Europe, the Pacific Rim, or the good old U.S. of A. Tallinn-based engineer Alfred Vassilkov, the author of the X Diamond and the guiding force behind Estelon, is a highly educated (he graduated from the same university as Vladimir Lamm and other celebrated audiophile émigrés from the Soviet Union), multiple-awardwinning designer, who is dead serious about creating the highestfidelity products possible and is intellectually, experientially, and artistically equipped to do so. Think of him as the Alon Wolf (also an émigré) of Estonia.

How Vassilkov solved the céramique conundrum is an interesting tale. To begin with, like someone else we know well from these pages, it occurred to him that cabinets that “play along” with their drivers—thus reinforcing any crossover-point glitches (such as, oh, a 7dB dropout between a midrange and a tweeter) or out-of-passband ringing (such as, oh, these same drivers chiming together like an ultra-high-frequency Big Ben at 15kHz)—are bad things. Vassilkov spent five years developing his solution: a gorgeous quasihour-glass-shaped enclosure sculpted to present the drivers with no parallel internal or external surfaces, while also supplying a narrow, rounded baffle for the tweeter (located in the middle of the speaker, at the “waist” of the hourglass) to achieve zero phase distortion at the listening position, and progressively larger radiuses for the midrange (located above the tweeter) and the woofer (located below) to provide the same ideal dispersion of each driver and the same uniform phase response at the listening seat.


To make this complex, highly-engineered “box” the perfect blend of stiffness, mass, and damping, Vassilkov experimented with many materials, eventually settling on a crushed-marble-and-acrylic-based composite that can be turned into a slurry, poured into a (very expensive) mold, cast in the form of an artfully sculpted loudspeaker enclosure (with extensive internal stiffening spars to break up resonance nodes and standing waves), allowed to age, and then hand-coated on the inside with layers of dampening materials and on the outside with layers of lacquer. Also on the inside, separate constrained-layer carbon-fiber chambers with non-parallel sidewalls provide ideal environments for the midrange and tweeter drivers.

Speaking of drivers, Vassilkov is perfectly aware of the “downsides” of ceramic cones, but believes that their upsides (at least in their latest versions—Accuton has greatly improved its ceramic cones and magnetic motors) outweigh their demerits, because of their high linearity throughout their passbands. By using only the latest and best Accuton cones—and very select and exceptionally closely matched pairs of each (Vassilkov goes through hundreds of these drivers and keeps only the scant few that meet his tolerances and standards)—putting them in an enclosure scientifically designed not to exacerbate their problems by “singing along” or introducing phase/dispersion/diffraction issues, ventilating their moving elements to assure “resonancefree” response, and using elegant electrically-simple secondorder crossovers (with Teflon-hybrid capacitors and air-core inductors encased in separate constrained-layer-damped carbonfiber chambers), he has sought to eliminate the céramique ringing/compression problem. How well he has succeeded—and he has, well—we will come to in a paragraph or two.

Vassilkov has done something else rather daring. While his 11″ sandwich woofer and 7″ membrane mid/woof use “conventional” (albeit highly select) ceramic diaphragms, he has chosen to use a 1.2″ inverted-dome diamond tweeter for the treble range. For all their undoubted technical superiority, in the past I’ve generally felt that diamond tweeters stick out like diamond sore thumbs. Yes, they are incredible transducers in their own right, capable of exceptional resolution, bandwidth, and low distortion. The trouble is I’ve always heard them “in their own right,” as audibly separate and separable parts of the presentation. Hearing a driver—be it diamond, ribbon, or beryllium—as a separate element violates my first rule of high fidelity, which is that a speaker’s (or any playback component’s) primary obligation is to disappear as a sound source. Diamond drivers haven’t done that.

Neither, with exceptions, have woofers in ported enclosures—and the X Diamonds have (Vassilkov-designed, ’natch) ports. While I’ve heard my share of vented speakers that didn’t seem to have the usual excessive port peak (followed by that 24dB/octave roll-off below, oh, 50Hz or so), I’ve generally preferred woofers in well-designed sealed-enclosures, simply because the bass tends to go deeper more linearly and I don’t hear the driver/enclosure interface in the same way that I do with ported numbers.

Add all this up and in spite of the time and care and sheer brain-power Alfred Vassilkov lavished on his incredibly high-tech enclosure, the unbelievably persnickety attention he paid to driver selection, mounting, and damping, the many engineering awards he has won in Europe, and the very positive experiences I’d had listening to the Estelons at various trade shows here and abroad, my expectations about a home-audition of the X Diamonds weren’t sky-high. I figured—in spite of Vassilkov’s art and science—those ceramic drivers would still ring and compress, the ported bass would thump, and that diamond tweeter would tear what’s left of my ears off. However, as I’ve already hinted, I couldn’t have been more wrong.

Let me just say this outright: The Estelon X Diamond is the most perfectly phase-coherent all-cone loudspeaker I’ve heard in my home. Outside of a Maggie or a mini like the Raidho C 1.1, I’ve rarely heard its like (and one of those is a line source and the other a stand-mounted two-way). Not only does the X Diamond defy expectations by sounding like one seamless thing from bottom bass (and its bass goes very, very deep—into the 20–30Hz range—and does so with superb definition, grip, color, and clarity) to top treble (absolutely no sore thumb here), but it is the first multiway cone speaker I’ve heard which not only completely disappears as a sound source but manages to replace its presence with the presence of the room or venue in which the recording was made. Like Maggies or mbls, the Estelon X Diamond simply carves out a different ambient space within the ambience of your listening room and disappears within it. That space expands, as with a classic left-right A/B-miked stereo recording like Ian and Sylvia’s Four Strong Winds [Vanguard], or contracts, as with the great monaural recording of Penderecki’s spooky Cello Concerto [Muza] superbly played by the great cellist Siegfried Palm, as the source dictates. But whether the stage is narrow or wide, shallow or deep, stunted or sky-high, the X Diamonds just don’t seem to be “projecting” it (or any parts of it) from box or drivers. The only other time I’ve had this experience with a large cone speaker (well, cone and ribbon) was with the Scaena 3.4 at CES a couple of years ago. The X Diamonds are that free-standing and that “not there.”

Now, I know I’ve made this claim about a “disappearing act” before, about the Magico Q5, for instance. But, as our Mr. Pearson was wont to say, you don’t know that something is better until you hear something better. In its “disappearing act,” at least as a relatively large physical object, the Estelon X Diamond sets a new standard, chez Valin, for big, multiway all-cone speakers.


Why should this be the case? To answer that let me return to something I said a paragraph ago about the X Diamonds not seeming to project their soundstage (or any parts of it) from a box or drivers. With large multiway cone speakers—even great ones—you occasionally get the sense that a particular note or pitch (particularly in the treble) is “coming from” a driver or (especially in the bass) a box. Warren Gehl of Audio Research calls this the “aperture effect.” What it amounts to is the downside of a point-source transducer and an enclosure. I don’t know if I can explain this clearly (and I certainly can’t do it scientifically), but the effect is easy enough to hear if you listen closely. In real life, instruments are indeed point sources, but they radiate their sound from that “point” spherically throughout three-hundred-and-sixty degrees. With stereo systems, deep bass frequencies are dispersed more or less spherically, but frequencies higher up are not. They do not behave like “pulsating spheres” but rather like expanding hemispherical or quasi-hemispherical rays. Because they are “raylike” there are times when little irregularities in frequency response or phase response or the effects of distraction, dispersion, reflection, or distortion let you trace them back to their source—to that “point” in space from which they originate (the driver or box).

I’m not just talking about gross persistent distortions like “one-note” bass or piercing treble here. I’m talking about (or trying to) the subtle ways in which a driver or an enclosure on and off reveals itself in playback. Every time your ear traces a note or a group of notes back to the loudspeaker, however briefly, the illusion that the presentation is a “free-standing” one, occurring in a space that is qualitatively different than the space of your listening room, is spoiled. If it happens often enough, you begin to lose concentration on the music (or I do).

Whether because of its highly engineered, sculpted, exceptionally “invisible” enclosure (and enclosure shape is a factor I hadn’t considered crucially important before the X Diamond—I won’t make that mistake again), its ultra-smooth blend of highly neutral and exceptionally linear drivers, or a combination of both, the X Diamond does not break the spell of listening to music seemingly played in a different space and time than the here and now of your room. It is an amazing feat of engineering prowess that makes for wondrous stereo.

The X Diamond wouldn’t be as special as it is if it weren’t also capable of exceptional resolution of inner detail, superb bass (the deepest, flattest, least colored, and best defined I’ve heard from a ported speaker), and excellent dynamic range. Like the Raidho C 1.1, to which it bears a marked sonic resemblance, this is a very high-resolution, very high-transparency transducer. While I’m not sure that it is quite as detailed as the great Raidho, it isn’t off by much. Indeed, if you can imagine a giant C 1.1 (which I may not have to do by imagination in the near future), you’ve got the picture (although I’d have to say that the blend of drivers in the Estelon is a little more seamless and phase/dispersion-perfect than the ribbon-cone Raidho).

Obviously, all of these virtues add up to one very realistic-sounding presentation, provided, of course, that the source is first-rate. With great electronics (such as Constellation Performance, Soulution 500, or Technical Brain Zero EX Series amps, preamps, and phonostages or ARC’s Reference 5 SE, Reference 250 monoblocks, and Ref Phono 2 SE), you consistently hear things that you simply cannot hear as clearly or distinctly on other speakers. Of course, I’ve written these same words dozens of times about dozens of components, because the truth is that every new piece of gear reveals new information at the same time it is revealing its own particular dynamic and harmonic emphases. But here the information isn’t a matter of a specific emphasis. In fact, it is so subtle and interesting that it kind of boggles the ear. Consider the Danish reissue of Lou Reed’s Rock ’n’ Roll Animal [RCA]. Recorded live in December 1973 at Howard Stein’s Academy of Music In New York, this is Reed at the height of his glam period (you almost get a contact high from touching the album jacket). The thing that is so amazing is that Reed doesn’t just sound like generic-70s Lou Reed—he sounds like a young Lou Reed, a thirty-year-old Lou Reed (which is what he then was, even though he may have had little idea of how old he was, where he was, or who he was at the time the recording was made). It is positively weird to hear a stereo system make someone sound younger than he does on other stereo systems—to hear speakers somehow capture the more boyish, more limber, less world-weary and more genuinely emotionally engaged (maybe because the band’s so good and the crowd so “into” it) timbre of his voice.

The illusion that you’re listening to a young Reed at his best wouldn’t be so convincing, so realistic, if it weren’t for the dynamic range of this loudspeaker, which, unlike so many previous ceramic-driver speakers, does not seem to be markedly compressing peaks. When Reed shouts (and it is a shout), “No, no, no, oh, Lady Day!” it raises goosebumps because of the way his voice leaps powerfully forward in the mix without the speaker going haywire and losing control, definition, or grip—or breaking the illusion that you’re in Stein’s Academy of Music, one of the crowd. While I’m not sure I could say that the X Diamonds cuts loose at big dynamic moments, like Tina’s bass guitar riff at the start of “Take Me to the River” or Byrne’s wonderfully near-hysterical “Hold me, tease me, love me, squeeze me/’Till I can, ’till I can, I can’t tell” the way the Magico Q5s did (and do), they’re close. The Estelons do give you a sense of grip and control even in extremis, but then so did the Q5s.

I don’t want to leave the impression that the X Diamonds are merely analytical “transparency to source” loudspeakers, although they are this, as well. (If you want to hear the differences between different brands of electronics more distinctly perhaps than you have before, try ’em with the X Diamonds.) These speakers are also ravishingly beautiful-sounding, with the right source. (If you really want beautiful, try ’em with the Carver Black Beauty 305s reviewed elsewhere in this issue.) To hear John Ogdon play the Shostakovich Concerto for Piano, Trumpet, and String Orchestra [Argo] through the X Diamonds is to hear a performance of consummate wit and beauty within a soundspace so distinctly different than that of your room (although it very nearly consumes your room from wall to wall to wall) that you can’t help feeling transported—as if you were there (as at Howard Stern’s Academy in 1973 or the Pantages Theater in 1983, where Stop Making Sense was recorded).

If a sense of being there—of being transported to a real place and a real performance—isn’t the greatest enticement this hobby can offer, then what is? Of course, the Estelon X Diamonds get my highest and most enthusiastic recommendation.


Type: Three-way floorstanding loudspeaker
Drivers: 11″ Accuton woofer, 7″ Accuton mid/bass, 1.2″ Accuton diamond tweeter
Frequency response: 22Hz–45kHz
Nominal impedance: 6 ohms
Sensitivity: 88dB/2.83V
Power handling: 200W
Recommended amplifier power: 20W or more
Dimensions: 1.5′ x 4.5′ x 2′
Weight: 190 lbs. (apiece)
Price: $65,000

US Distribution:
Alfred & Partners

JV’s Reference System

Loudspeakers: Raidho C1.1, MartinLogan CLX , Magnepan 1.7, Magnepan 3.7, Magnepan 20.7
Linestage preamps: Constellation Virgo, Audio Research Reference 5SE, Technical Brain TBC -Zero EX
Phonostage preamps: Audio Research Corporation Reference Phono 2SE, Technical Brain TEQ -Zero EX/ TMC-Zero
Power amplifiers: Constellation Centaur, Audio Research Reference 250, Lamm ML2.2, Soulution 501, Carver Black Beauty 305, Technical Brain TBP-Zero EX
Analog source: Walker Audio Proscenium Black Diamond Mk III record player, AMG Viella 12, Da Vinci AAS Gabriel Mk II turntable with DaVinci Master’s Reference Virtu tonearm, Acoustic Signature Ascona with Kuzma 4P tonearm
Phono cartridges: Clearaudio Goldfinger Statement, Ortofon MC A90, Benz LP S-MR
Digital source: Mac Mini/Wavelength Audio Crimson USB DAC, Berkeley Alpha DAC 2
Cable and interconnect: Synergistic Research Galileo, Crystal Cable Absolute Dream
Power Cords: Synergistic Research, Shunyata King Cobra
Power Conditioner: Synergistics Research Galileo
Accessories: Synergistic ART system, Shakti Hallographs (6), A/V Room Services Metu panels and traps, ASC Tube Traps, Critical Mass MAXXUM equipment and amp stands, Symposium Isis and Ultra equipment platforms, Symposium Rollerblocks and Fat Padz, Walker Prologue Reference equipment and amp stands, Walker Valid Points and Resonance Control discs, Clearaudio Double Matrix SE record cleaner, HiFi-Tuning silver/gold fuses


By Jonathan Valin

I’ve been a creative writer for most of life. Throughout the 80s and 90s, I wrote eleven novels and many stories—some of which were nominated for (and won) prizes, one of which was made into a not-very-good movie by Paramount, and all of which are still available hardbound and via download on Amazon. At the same time I taught creative writing at a couple of universities and worked brief stints in Hollywood. It looked as if teaching and writing more novels, stories, reviews, and scripts was going to be my life. Then HP called me up out of the blue, and everything changed. I’ve told this story several times, but it’s worth repeating because the second half of my life hinged on it. I’d been an audiophile since I was in my mid-teens, and did all the things a young audiophile did back then, buying what I could afford (mainly on the used market), hanging with audiophile friends almost exclusively, and poring over J. Gordon Holt’s Stereophile and Harry Pearson’s Absolute Sound. Come the early 90s, I took a year and a half off from writing my next novel and, music lover that I was, researched and wrote a book (now out of print) about my favorite classical records on the RCA label. Somehow Harry found out about that book (The RCA Bible), got my phone number (which was unlisted, so to this day I don’t know how he unearthed it), and called. Since I’d been reading him since I was a kid, I was shocked. “I feel like I’m talking to God,” I told him. “No,” said he, in that deep rumbling voice of his, “God is talking to you.” I laughed, of course. But in a way it worked out to be true, since from almost that moment forward I’ve devoted my life to writing about audio and music—first for Harry at TAS, then for Fi (the magazine I founded alongside Wayne Garcia), and in the new millennium at TAS again, when HP hired me back after Fi folded. It’s been an odd and, for the most part, serendipitous career, in which things have simply come my way, like Harry’s phone call, without me planning for them. For better and worse I’ve just gone with them on instinct and my talent to spin words, which is as close to being musical as I come.

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