Sonja XV Loudspeakers from YG Acoustics
The Sonja XV was well-deserving of the attention it attracted in its large suite. The speaker's title is actually pronounced Sonja "X" "V", with the "X" standing for extreme version, and the XV signifying the company's 15th anniversary. As with all YG speaker models, the Sonja XV is named for a family member, who in this case is Yoav's wife. The Sonja XV, I might add, is certainly a loudspeaker system that many would wish to marry for a lifetime.
With a shipping weight of 1.3 tons, this is YG's first four-way loudspeaker. All drivers are manufactured in-house, which in this case means one very unique ForgeCore tweeter, two BilletCore mids, three BilletCore mid/woofers, and four BilletCore woofers. All drivers are milled from aircraft-grade, solid-core aluminum. The speaker claims a sensitivity of 88dB/2.83 V /1 m, and a 4-ohm nominal impedance that does not dip below 3.5 ohms. (Yoav explained that the speaker has a 4-ohm sensitivity overall, with 8 ohms in the bass and mid-bass.) 250 CNC machining hours are required to manufacture its 6200 parts.
The tweeter has special ribbing on the back to make it extremely stiff without adding additional weight. Its soft silk dome is treated with epoxy, and has glued within it a BilletCore-milled light aluminum airframe that can hold 120,000 times its own weight without deforming. YG has some videos online that will make this easier to visualize.
Yoav is the sole designer of the technology, including the crossover and the software necessary to complete the design. Two other YG employees help him optimize details. "This is an all-passive loudspeaker," he told me before I listened. "That's the direction I'm going, because it allows me more control of the crossover and the ability to design whatever I would like."
Despite its size, the Sonja XV can be auditioned at GTT in New Jersey, with at least one more dealership expected to come on board. It's also available for listening in Japan and Korea (so far).
Original plans were to mate the speaker with a prototype of the forthcoming Audionet Heisenberg mono power amplifiers ($105,000/pairvirtually the same price as the new Nagra amplifiers) and Stern stereo preamplifier ($45,000). Given some incomplete circuitry in the former, it was replaced by the same Audionet MAX mono power amplifiers ($30,500/pair) that I'll be reviewing for Stereophile, as well as the Audionet PRE G2 ($23,350).
Other components included an MSB Select DAC w/power base ($89,950) and UMT transport w/dual power base ($11,990); Kubala-Sosna Xpander power distribution box ($5400) and Realization cabling; and YG Acoustics rack 1.3 ($14,850). Add in the analog section from Kronos, Airtight, and Audionet, which I did not audition, and you end up withdrawing from your bank account or offshore depository $634,790, plus the hardly-insubstantial price of the cables. Then again, to put it all in perspectiveI know, whose perspective?the Wilson Audio WAMM costs $685,000/pair.
On my SACD of San Francisco Symphony's rendition of the works of Mason Bates, the soundstage was hugeHUGEwith the low frequencies remarkably fleshed out and layered. Everything was perfectly controlled, with the speed, power, and weight of bass response astounding. Highs, however, were a bit recessed, and lacking in brilliance, and strings briefly turned wiry on the track's loudest passage.
Even more astounding, if I may be allowed a double superlative, was the sound from my SACD of Heitor Revueltas' Sensemaya (Channel Classics). Bass was awesome, images huge, and detail up there with the best. What I missed, however, was some of the inner warmth and transparency I'm accustomed to, as well as sparkle on top. In all fairness, the Wilson Audio WAMM sounded even less transparent, and devoid of the brilliance I hear from other Wilson models. Even as jaws around me droppedyou've got to give these speakers a major bass workout to appreciate Yoav Geva's achievementI began to wonder if, perhaps due to the room itself, the midrange was over-emphasized.
When all is said and done, I was at a show, staged in a hotel whose host of variables cannot be addressed in the short set-up time allowed exhibitors. Only a detailed review can do these speakers full justice.