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.