YG Acoustics entered the specialty audio scene at the upper end of the full-range, high-performance speaker market right from its beginnings. It did not build a line of mid-priced products to establish marketshare and then “design up” from there. YG applies a fundamental design principle to all its loudspeakers—they must simultaneously have near-zero relative phase and flat frequency response. Apparently, optimizing both is fairly difficult; phase or frequency performance is usually favored at the expense of the other. In order to realize this goal, some key engineering elements must work together at very precise levels, and thus YG’s nearly obsessive attention to high-quality materials and manufacturing exactness means that its products remain expensive—$24,300 to $106,800. YG would rather stay true to its ethos than compromise in order to offer a more market-accessible product range.
YG was founded in 2002 in Israel, but really didn’t begin to develop its manufacturing potential until it opened its current factory in 2004 near Denver, Colorado. It is the creation of Yoav Geva, a relatively young man—as far the principals of high-end companies go—still in his mid/late thirties. Geva applied some of his experience in digital signal processing to an algorithm in the analog domain, which, in turn, formed the foundation to his proprietary phase/frequency-optimized crossover design. YG calls the technology “DualCoherent,” and it is, as mentioned, the raison d’être of the company. Based on extensive modeling of his concept, Geva knew he needed to build speaker cabinets from a more rigid and stable material than was possible with wood, or he would not be able to execute the very close interplay among the various parameters involved in his design.
Accordingly, YG machines a great deal of its products’ contents from high-quality aluminum billet. Machined aluminum provides several advantages as a cabinet and cone membrane material: good strength-to-weight ratio, relatively high resistance to environmental factors such as corrosion and high temperature (helpful when machining friction heats the stock), the ability to be machined into a wide variety of custom shapes to very precise tolerances. Aluminum also has relatively good resonance damping characteristics when properly constructed. YG uses mostly aircraft-grade 6061-T651 billet. I’ve visited the YG factory and have to say that the CNC machines (computer numeric control) are truly impressive. Each “BilletCore” radially and concentrically ribbed driver cone takes at least four hours to mill on a five-axis CNC milling and turning machine from Germany called the Gildemeister CTX Beta 1250 TC. Many parts are machined to within 0.0008" (20 micron) tolerances. (For more information about YG, please see the company’s profile in The Absolute Sound’s Illustrated History of High-End Audio, Volume One: Loudspeakers.)
The two-module Sonja 1.2 is priced at $72,800 per pair and is available as a fully passive system (as reviewed); alternately, its bass module can be equipped with a powered, adjustable on-board amplifier and crossover to form a semi-active system for the same price. Consumers may also opt for the flagship Sonja 1.3, which adds yet another woofer module (also passive or powered to match the existing 1.2 bass module), bringing the price to $106,800 per pair. The three-module configuration increases the height from 51" to 70", and the weight from 296 pounds to 506, making the more imposing 1.3 a good fit for listeners with a large—or otherwise bass-attenuating—listening room and/or for those craving truly effortless and impactful bass. I have heard both the 1.2 and 1.3 in a few different installations. The 1.2 will be plenty of speaker for most home listening applications, but the 1.3 does deliver better performance overall; the additional bass module seems to add even more ease and clarity to the entire presentation, not just in the low end. Both the 1.2 and 1.3 are usually purchased in their fully passive versions, just as YG recommends.
The upper module houses two 6" aluminum “BilletCore” mid/woofers, and one 1" waveguide-mounted “ForgeCore” silk dome tweeter in a D’Appolito arrangement (a tweeter flanked by midrange drivers above and below the tweeter). The waveguide apparently aids in making the dispersion pattern of the tweeter closer to that of the mid/woofers. (The crossover point between the bass module and upper module is 65Hz and is, presumably, why YG refers to the mid-sized drivers as mid/woofers rather than midrange drivers.) The two-way, 124-pound upper module (known as Sonja 1.1) can be purchased separately as a stand-mounted monitor for $38,800; the bass module can be added later to form the three-way Sonja 1.2 system. The bass module has one “BilletCore” 10.25" driver, which is positioned fairly low in its gently curved, tapered cabinet. YG found this location maximized consistent bass performance through the driver’s proximity to the floor and also minimized cabinet resonances. Each module has an inner cabinet that is mounted inside an outer cabinet. They are not merely double-layered as such. Each box has its own joints and can function as a stand-alone enclosure. This extra manufacturing complexity must surely add significantly to the overall cost, but YG says its makes each complete cabinet system much more rigid and resonance-free than either an equivalently thick, single-layered or a shared-joint, double-layered cabinet. Sonja is the only model in the line with this cabinet-in-cabinet construction. The 1.2 has three pairs of custom binding posts for single-wiring, bi-wiring, bi-amping, tri-wiring, or tri-amping.
YG has executed a stunning design in the Sonja, and in order to deliver the kind of performance and quality involved, the company has gone to very costly lengths to bring it to market. As far as super-speakers go—the cost of which can rise well over $150,000 per pair—the Sonja 1.2 is priced relatively competitively. Taking into account high-end audio pricing in general and given my sense of what goes into making the Sonja specifically, I believe the 1.2’s pricing is well within industry norms. For whatever it is worth, YG has invested over $1m in German and custom-built CNC machines, and sources all of its materials and parts from either North American or European suppliers (like top-level Mundorf capacitors and resistors). YG manufactures the vast majority of its parts itself including fasteners, driver components, binding posts, and even proprietary toroidal inductors. The amount of in-house manufacturing is very high and accords YG an astonishing level of control and precision, all of which add to the cost of production.
As already mentioned, the Sonja 1.2 is simply stunning—dynamic range, frequency extension, tonal purity, transparency, soundstaging and imaging...all stunning, sometimes goose-bump-inducing, and often involuntary grin-raising as it calmly goes about its musical business. The Sonja 1.2 does not have an easily identifiable dominant sonic character such as “lively” or “silky,” nor does it have an apparent bottom-up or top-down tonal balance. Rather, the 1.2 seems to simply convey the content of the recordings it is tasked to play back—and the characteristics of the gear with which it is partnered, of course—without adding much apparent character of its own. Its dynamic envelope is very wide, and yet it is also able to track delicate dynamic shifts. It is, in fact, capable of planar-like detail retrieval, purity of timbre, and overall refinement. It also conjures—recording permitting—a very large soundscape, and populates it with solid, naturally focused individual images without exaggeration or etch. So, at the end of the day, you have a remarkably transparent, dynamically deft, and musically expressive loudspeaker with the ability to recreate an expansive and focused soundstage. As you can tell already, in pretty much any regard, the Sonja 1.2 did not disappoint.
One of the main differences I heard when the 1.2 replaced the YG Kipod II (Issue 236) was the effortless way the 1.2 breathed yet more lifelike dynamic snap and immediacy into nearly every recording I played. The Sonja set an entirely new performance level in my system in terms of its overall dynamic envelope and lack of apparent distortion in explosive bass-heavy passages. The bass drum strikes at the end of Rabaud’s Dances from Marouf, Cobbler of Cairo on the DSD download of Exotic Dances from the Opera [Oue, Minnesota, RR] just sailed by with much of the percussive thrill of a live orchestral crescendo and no signs of strain. The 1.2 also conveys small dynamic shadings beautifully. It can sound like a fantastic mini-monitor, or a fine planar speaker, in its ability to communicate subtle differences in dynamic emphasis, the sort of shadings musicians seem to naturally use to create drama and lyricism in their performances. Take the song by Anouar Brahem called “L’aube” on Le Voyage De Sahar [ECM], for example, in which Brahem plays his oud with such delicate touches that it evokes the mood of a calm, morning bath. The full extent of the peaceful, focused beauty of the song doesn’t come through on less dynamically adroit speakers.
Other standout qualities are the 1.2’s marvelously extended frequency range and tonal accuracy. YG says, “Usable output extends from below 20Hz to above 40kHz.” I believe the phrase “usable output” refers to how the speaker’s bass interacts with room boundaries in a typical domestic setting to yield a lower frequency response than would otherwise be the case in an anechoic test chamber. Putting aside how this may compare to more traditional +/-3dB specifications, I can say the 1.2’s bass extension certainly sounds convincingly full-range in my setup, and in every other system in which I have heard it. The low notes on Joseph Bonnet’s “Variations de Concert,” played by organist Jan Kraybill [Organ Polychrome—The French School, RR], sounded deep-reaching, full, and well defined in pitch, without room-induced overhang or bloat. The synthesizer bass notes on the Aphex Twin’s Syro cut called “s950tx16wasr10 (earth portal mix),” were so deep and powerful, they bordered on frightening, such were the grip and speed with which the lowest notes launched into the room.