The new Sonja 2.2 has three main changes (and one minor one) over the previous 1.2. First, and most significantly, all Sonja 2 models have a new kind of tweeter. Geva has merged a soft-dome membrane with a supporting lightweight, rigid, acoustically transparent frame made from—you guessed it—precision-machined aluminum billet. YG’s new BilletDome soft-dome/frame tweeter actually represents a technical breakthrough in tweeter design for which the company is applying for a patent. Soft domes can sound very good, but they are simply not stiff enough to withstand the acceleration forces exerted on them while playing at higher frequencies and at higher amplitudes without deforming, resulting in distortion. Many metal-dome tweeters (regular or inverted) can also sound quite good and are generally stronger and more uniformly pistonic in their motion, but they are also known for “ringing” at high frequencies, thus creating unwanted resonances and a different sort of distortion. Even if the ringing can be shown to be above the limits of human hearing, many listeners can still discern a harshness in some speakers with metal tweeters, especially during demanding music passages. These are basic generalities, of course. I am leaving out other tweeter types, such as ribbons, electrostats, and magnetostats because I am simply not qualified to discuss them. (Ceramic and diamond-coated domes also have their pros and cons, but, again, I am not qualified to speak to them.) After nearly two years of R&D, Geva successfully bonded a high-quality silk dome membrane over a strong and very lightweight (30 milligrams) “airframe.” This apparently makes the resulting tweeter stronger than the strongest all-metal tweeter but without a metallic ringing quality. YG has done acceleration tests (based on pressure measurements) of titanium and beryllium tweeters and can demonstrate that its BilletDome tweeter withstands about twice as many G-forces as a titanium tweeter and about 38% more than a beryllium one. The airframe is shaped to be acoustically transparent, very strong, and light enough so the that combined moving mass of the soft dome and its airframe are roughly equivalent to that of a metal dome. I will say, I have heard some great-sounding speakers with treated metal dome tweeters such as the upper-level Focal models—and I tend to be agnostic about specific materials in general—but the YG BilletDome tweeter sounds fabulous in the Sonja 2.2 and Sonja XV.
Second, the crossover was changed to accommodate the new tweeter’s electrical and acoustic properties, and also to allow the speaker to perform more efficiently in the lower frequencies. YG says that rather than having the speaker favor mainly higher-powered, high-current amplifiers, a greater variety of amps can now extract more of the Sonja’s available bass extension.
Third, the bass module cabinet is now 25 pounds lighter and also stiffer. According to YG, “the new construction is 8% lighter and over 10% stronger, which leads to an overall 20% improvement in the enclosure’s strength-to-weight ratio.”
The fourth change is more a matter of rear-panel cosmetics and user convenience than a performance-enhancing update. The older 1.2 has three pairs of binding posts. The new 2.2 has two pairs and is the only readily apparent visual difference between Sonja 1.2 and 2.2 (unless you look closely at the tweeter). The back of the Sonja 2.2 is cleaner looking because the two modules’ binding posts are now in matching insets that meet each other at the modules’ junctures.
Sonja 1 owners may upgrade their speakers (not including the cabinet update) to “Sonja 2 technology,” as YG phrases it, for $9400 (2.1) $14,800 (2.2), and $16,800 (2.3) respectively. YG will also upgrade the cabinet, but it requires more modifications and an additional charge.
In my review of the original 1.2, I wrote the following to frame my overall impression, “the Sonja 1.2 is simply stunning—dynamic range, frequency extension, tonal purity, transparency, soundstaging, and imaging...all stunning and sometimes goosebump-inducing and involuntary grin-forming as it calmly goes about its musical business. The Sonja 1.2 does not have an easily identifiable dominant sonic character such as ‘liveliness’ or ‘silkiness,’ 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 much apparent imposition of its own.”
That summary still applies to the new 2.2 but is augmented by even greater resolution, ease, and general facility. The sonic sum of the Sonja 2 changes seem to amount to more than their updated constituent parts would initially indicate, although the new BilletDome tweeter certainly is an obvious technological advancement. The level of resolution of fine detail is improved. Initial transients and timbre are better fleshed out. Decays and spatial cues are clearer and easier to follow. Loud peaks are more explosive while also sounding more composed or “cleaner.” In short, music simply sounds more present and impactful—as the recordings themselves allow. A real bonus with the new version’s increase in fine resolution is that it is not accompanied by a tonal emphasis shift, which can make a speaker sound as if it is forcing details on the listener, a flaw too often associated with speakers with “high-resolution” ambitions. In fact, the Sonja 2.2’s greatest strength, in my opinion, is its uncanny level of resolution and its lack of apparent artifice or strain. One can more easily relax and enjoy the music as it unfolds because there is so little hardness in the upper frequencies. “Detail and ease” seems to be a theme that a select group of excellent speakers embody to a much greater extent than merely good speakers do. Count the Sonja 2.2 among that select group.
The outer extent of the soundscape is also expanded, especially horizontally. This expansion is not overwhelmingly better than with the previous version, in which soundstaging was already a strong point, but it does impart an impression of greater openness. Recording and upstream system quality permitting, the stage extends well outside the cabinets in a room-boundary-defying display that helps mitigate the limitations of my smallish 12.5' x 17' room. Compared to most other speakers, the soundstage sounds as if the YGs were placed about two feet farther apart and in a slightly larger room than they actually are. Individual images within the larger soundscape are focused, not in an exaggerated, hyped-up way, but in a manner that simply makes subtle musical elements more discernible. On the Stravinsky Song of the Nightingale LP [Oue/Minnesota, RR], I could easily visualize the orchestral sections arrayed before me, and there was enough information to convincingly portray individual instruments within those sections. Overall soundstage depth and height were also strong points, as were individual image depth and image density. Perhaps the most salient soundstaging characteristic lay in the continuousness of its entire sound envelope such that the speakers are sometimes not discernible as the source of the sound. On some recordings, like the Classic Records LP reissue of the Prokofiev Lieutenant Kije [Reiner/CSO, RCA], it is as if the 2.2s just happen to occupy the same part of the room where the soundscape exists, so complete is the apparent detachment of the sound from the speakers.