The question is actually a very simple one: Are you an audiophile whose ears are attuned to the sound of live, unamplified acoustic music performed in a natural setting—traditionally defined in these pages as “the absolute sound”? If the answer is yes, Vandersteen Audio would very much like to talk to you. For this is the milieu of its Treo CT, a mid-sized floorstander that, at $7990, resides midpack in the Vandersteen lineup. It’s a loudspeaker that has an uncommon reverence for the music that poses the greatest challenges to an audio system. Reproducing the context and complexities of performance and venue, harmonics and ambience, the micro and the macro is where the Treo CT shines at its most brilliant.
The Treo CT silhouette will be instantly familiar to longtime audiophiles, and not just to Vandersteen fanciers. Elements of this classic look—the slanted front baffle to time-align the drivers, the cabinet widening and deepening as its non-parallel sidewalls flow into its base—have appeared in varying degrees from makers as disparate as Thiel, Avalon, Rockport, Wilson Audio, and, more recently, newcomers like Ryan Audio.
The Treo CT is a four-way floorstanding loudspeaker in a bass-reflex enclosure. (The single port fires downward from the speaker’s base.) It shares its general architecture and transducers with the Quatro Wood CT—a hybrid iteration with a powered bass system. CT stands for carbon tweeter—an evolution of the driver type first developed for the Model Seven flagship, later migrated to the Model 5A Carbon, and now an option with the CT (the standard Treo lists for $6900/pair). For Vandersteen, carbon-driver cones offer the pistonic linearity of metal drivers without their inherently unnatural and amusical sonic colorations (known as ringing in some circles)
True to Vandersteen tradition, the Treo CT is a time-and-phase-correct loudspeaker. The crossovers are first-order, impedance-compensated numbers individually tuned in an anechoic chamber. Crossover points are specified at 80Hz, 900Hz, and 6kHz. As a first-order design, much is asked and expected of the drivers in extended operating range and dynamic demands. To these ends, the drivers include a CT tweeter and Vandersteen’s “reflection-free” 4.5" midrange in a proprietary transmission line that breaks up energy from behind the driver rather than directing it back into the cone. The mid/bass driver is a 6.5" tri-woven cone, while the bass is handled by a ported, carbon-loaded, ultra-long-throw 8" woofer
Vandersteen describes its dense, narrow, rigid enclosures as “minimum baffle” designs that minimize diffraction effects and time-smearing reflections. Construction is in a word, extreme. Vandersteen has engineered a unique system that it describes as “cabinet-within-a-cabinet” construction—essentially an inner MDF cabinet within an outer MDF enclosure, separated by a viscous or “gooey” membrane that eliminates resonances. Vandersteen reports that “measurements bear out that this gives us the kind of silent cabinet performance that is typically seen only in very exotic cabinets made with exotic materials…we only exceed this by combining similar techniques with superior and much more expensive materials, like the carbon fiber in our Model Seven Mk II flagship or even the multi-layer head in the Model 5A Carbon.” Curiously, the Treo CT still uses a terminal plate rather than multi-way binding posts for speaker-cable hookup (bi-wire or single). This reduces cable termination options to bare wire or spades. However, Vandersteen argues that since “the barrier strip terminals are soldered directly to the board on crossover networks, this makes the connection 100% impervious to oxidation and other environmental elements that can corrupt connections over time.” Vandersteen adds that wiring directly into the crossover board avoids any full-range wiring inside the speaker, which is a big plus sonically.
A word about the Treo CT speaker grilles: Don’t touch ’em, as they are meant to be left on. Yes, this runs counter to audiophile gospel, which maintains that grille cloths reduce acoustic transparency, but the Treo’s grille is anything but ordinary. Rather than a thin, cheesy frame with a sheer cloth membrane, it is actually a physical extension of the baffle itself—literally completing the front baffle in the way a final piece of a jigsaw puzzle finishes the pattern. Feel free to remove them when you audition the Treo CT, but my bet is that you’ll reattach them pronto. In my observations they were integral to the level of imaging and coherence that the Treo CT was capable of achieving. The set-up manual is very explicit about placement and provides graphs for optimization. The robust and adjustable cone-footers, three to a side, significantly aid in fine-tuning.
Sonically, the Treo CT offered a near-full-range experience with exceptional balance, nuance, and continuousness. Its presence in the room was felt immediately in bass response that extended with authority and finesse into the thirty-cycle range. The Treo’s was not a heavy or ponderous balance either; rather there was a lightness to its overall personality that belied the power of a four-driver configuration. Tonally, it perches on the warmer and more relaxed side of neutral, but this trait only manifests itself in contrast with designs that have a drier, more forward, studio-monitor-type sound. The Treo CT has a midrange that calmly draws listeners in rather than forcing them away. There’s a civility to the way it steers clear of carving out the last iota of so-called detail or of vying for your attention with a too prominent treble. For example, the top end of the Vandersteen had the air and fluidity that brought the chorus of the Rutter Requiem startlingly to life in my listening room. Individual soloists remained cleanly defined and focused amidst the chorus, which led to moments so detailed that each line of vocalists was clearly imaged on the ascending risers of the stage.
There’s an implicit sweetness to the carbon tweeter that produces a sibilance range that is well nigh perfect. The Treo captured the leading-edge intensity of singers like Norah Jones and Holly Cole without turning up the sizzle in this precarious treble region. The CT’s stock-in-trade was true treble resolution as distinguished from the false detail of many above-average tweeters that are dogged by material colorations.
Thus, piano transients and macro-dynamics were potent and aggressive in the way a grand piano is meant to be aggressive under a heavy hand, yet never veered into hard steely territory. And soundboard harmonics rose into the listening space as if borne aloft on cushions of air. In the CT we have the rare tweeter that places its attention squarely on the music without drawing any attention to itself.
The Treo has such an expressively wide color palette and fine resolution of timbral contrasts that it almost seemed constrained within the musically narrow confines of a typical, studio-sired rock production. In fact, the more musical complexity I threw at the Treo CT, the happier it seemed to be. Whether I was listening to a brass ensemble, or a classical chamber group, or a percussion section, each note was unique in time, fully differentiated in micro-information. The Treo was equally sensitive to the resonances of string instruments, easily distinguishing the unique accents of violin or viola, or the scale of different guitars from auditorium-size dreadnoughts to smaller parlor instruments.
As I listened to Copland’s majestic Fanfare For the Common Man, I encountered bass response that excelled in pitch definition and tunefulness. Although the raw dynamic energy and extension of the percussion section’s timpani and bass drum didn’t leave craters in my listening room (see the Quatro Wood CT for that), the Treo CT performed without port noise, chuffing, or the sensation of overhanging notes clinging to the fundamental as if trying to catch up with a performance that had already moved on. During tracks from Appalachian Journey, cello and bass viol consistently exhibited a fine body of warmth and detail, though to my ear they did not quite fully ripen with the weight and resonance I know this recording has in abundance. As I’ve mentioned, the Vandersteen, while touching on the bottom octave, begins to run short of breath in the lower-30Hz range.
Throughout this evaluation there was one trait that, like an addiction, continually fueled my excitement for the Treo CT. It was the speaker’s of-a-piece coherence. This is not always a given in the high end. Many multiple-driver loudspeakers—primarily designs with three or more transducers—fail to speak with one voice. Instead, the listener can identify each driver as it jockeys for prominence up and down the front baffle. In contrast, the Treo CT was like a top-drawer two-way compact—a segment long celebrated for its ability to reveal three-dimensional space while remaining invisible as a sound source. Similarly, the Treo CT (far better proportioned across the frequency spectrum than a two-way) projected a vast image of the legendary Chicago Symphony Orchestra performing the Beethoven Ninth. Its spread across the soundstage was replete with height cues that reached well above the speaker, and depth cues that drew my eye to the back wall of the hall each time the percussion section lit up and the vast chorus rose in intensity. Much of the credit for this level of spatial precision is certainly owed to Vandersteen’s time-and-phase-correct philosophy, but it’s also due to the inert cabinet and well-controlled port. You don’t need the classic “knuckle rap” test to determine that the Treo’s cabinet doesn’t appear to be a source of (mis-)information. You just need to listen to Dick Hyman’s “Moonglow” (From the Age of Swing on Reference Recordings) to hear how each instrument rings true, utterly free from the common cabinet-borne colorations encountered in lesser designs. Piano, brass, random bass lines, lone ride-cymbal…each instrument seemed physically engraved into the soundspace.
There is a visual analogy that further describes my experience with the Treo CT. It reproduced the panorama of symphonic music with the kind of deep color, dimensional presence, and soundstage continuity of classic widescreen films. It did so with an edge-to-edge, corner-to-corner imaging precision that few loudspeakers at any price have achieved in my room. It cleanly defined and delineated player after player, elbow to elbow within each section of the orchestra, as if they were being photographed through a lens of unparalleled clarity and infinite depth of focus. It balanced the dual imperatives of image and ambience in much the same naturalistic manner that (I think) is still unique to film. Compared with the slightly cooler, harder, edge-enhanced super-reality that often defines digital technology, the Treo CT conveyed a more fluid and realistic representation of the symphonic experience in a real hall. Not softer in resolution, but more attached to the air and atmosphere of its surrounding environment.
Even though I think the Treo CT’s charms were more fully appreciated in the classical and acoustic arena, the speaker, without question, provided a highly satisfying pop/rock experience. As I listened to the opening bass and drum groove of Fleetwood Mac’s “Dreams,” there was a rewarding sense of unalloyed midbass punch, drum fills, and concussive forward-leaning drive that was riveting. As penetrating and electrifying as another personal favorite, the similarly scaled Wilson Sabrina? No, not quite, but competitively close and less costly. Sabrina, of course, has other charms not the least of which is greater low-end extension and dynamic output, but for overall transparency and resolution these rivals share more similarities than differences. The last pop track I played on the Treo CT prior to submitting this review actually turned into a double farewell. That morning I learned of David Bowie’s death from cancer at the age of 69. I thought it was fitting that I should see him and the Treos off by playing one of my favorite LP remixes, “Let’s Dance” [EMI]. The Vandersteens seemed to rise to the occasion, digging deep into the heavy dance groove, launching wave upon wave of kick-drum pulses, driving Stevie Ray Vaughan’s searing guitar solo through the air, handily reproducing the screaming saxophone work and, above all, Bowie’s sly, richly resonant vocal, sensually massaging a lyric so very much about being alive and in love.
When all is said and done, there are speakers we’ve all encountered that, however admirable, are more about quantifying information than reproducing a moving, organic musical event. They might sound lively for a spell, but they lack the heartbeat of musicality. It’s a rookie mistake that only years of experience can ameliorate. Vandersteen Audio, however, is an old-guard veteran, and it shows. It takes just one listen to the Treo CT to recognize that you’re in the presence of a speaker that superbly balances these twin essentials, but never loses sight of where its loyalties lie. In my view, you cannot get a more purely musical loudspeaker in this price range than the Treo CT. A true delight.