PSB Synchrony One loudspeaker
Cantus producer Erick Lichte and I were working on the preliminary mixes for the choir's forthcoming album of works by contemporary American composers, which we had recorded last June at Goshen College, Indiana. I was sitting at the computer, Erick in my listening chair, and we were using PSB's Synchrony One towers as monitors.
"Ah." I tried not to look sheepish. "I forgot to time-align the outputs from the three pairs of microphones I used."
Now, it's fair to note that the improvement made by time-aligning microphones is not one of night and day. But it is an improvement, and such was the resolving power of the PSBs that the degradation in the stability and focus of the soundstage due to the different arrival times was very audible. Sliding the pairs of microphone tracks forward and backward in time to synchronize the waveform in each of a centrally placed slapstick brought the image of the choir, as heard through the Synchrony Ones, into precise focus.
Synchronicity
The Synchrony One, an elegantly proportioned tower 43" tall, is the flagship of a line of seven new models from Canadian manufacturer PSB. I saw a prototype at the Consumer Electronics Show in January 2007, and the speaker was officially announced the following September, at the CEDIA Expo. The first thing that strikes you is that there are three 6.5" woofers, one each at the top, middle, and base of the enclosure's front. A 4" midrange unit lies immediately below the top woofer, and a 1" titanium-dome tweeter is placed below that, just above the middle woofer. The second thing that strikes you is the absence of any visible mounting hardware—each of the five drivers is smoothly integrated into the front baffle of black-anodized, extruded aluminum.
In fact, the drivers are mounted to an aluminum sub-baffle, with a ring of hard, molded rubber smoothly filling the space between the surround and the curved front of the baffle. Each woofer is loaded with its own vented subenclosure, the three ports firing from the black-aluminum rear panel. The placement of the woofers on the front baffle, the exact reflex tuning for each, and the crossover filter slopes—each is fed from its own low-pass filter—as well as the placement of the midrange unit, were arranged to eliminate the usual "floor dip" in the response that results from destructive interference between the drive-units' direct sound and the reflection of that sound from the floor. It is relatively straightforward to arrange for the floor dip from the midrange unit to occur below its passband and that from the lowest woofer to occur above its passband, but optimizing the behavior of the two upper woofers must have been a more complex matter.
The tweeter uses a neodymium magnet. Electrical connection to all five drivers is via two pairs of binding posts inset at the base of the rear panel, and the upper crossover is a Linkwitz-Reilly type, to give minimal overlap between the tweeter and midrange unit and optimal dispersion. The lower-frequency drivers have cones of felted natural fibers laminated with fiberglass to get the requisite combination of lightness, stiffness, and self-damping. Rather than a conventional dustcap, each has a central, stationary, aluminum "phase plug" attached to the front of its voice-coil former. Copper shorting rings on the voice-coils and aluminum rings on the rear of the magnets are said to keep THD in the midband below 0.1% at 96dB SPL, which is more akin to amplifier behavior. The result, says PSB's founder and chief engineer, Paul Barton, is a speaker that goes louder and deeper more cleanly than his flagship Stratus Gold i of a decade ago, while being smaller and more elegant in appearance.
When launched 11 years ago, the Stratus Gold i cost $2499/pair; the Synchrony One costs $4500/pair, which is actually less expensive when inflation is taken into account. This is made possible by the new speaker being manufactured, as are so many others these days, in China. But also like many other Chinese-made speakers, the Synchrony One's fit'n'finish are world-class. The enclosure's gracefully curved, veneered sidewalls, laminated from seven layers of MDF, are seamlessly fitted to the extruded-aluminum front and rear baffles. The black grille of cloth on perforated metal seamlessly fits into vertical slots either side of the drive-units. The visual impression given by the speaker is of understated elegance.
Sonics
With its unique multiple-woofer arrangement, I was expecting the Synchrony One to be more tolerant than the norm regarding placement in my listening room. That turned out not to be the case. It was difficult to eliminate a residual warmth that added a "humming" quality to the sound of a piano's lower register. I did wonder for a while if what I was hearing was the absence of the usual floor-bounce notch in the lower midrange, but eventually I was convinced that it really was part of the speaker's character. The solution was to use one of the PSB-supplied rubber plugs to block the port loading the bottom woofer of each speaker. While the speaker's balance was then still on the warmish side, this modification cleaned up the reproduction of lower-frequency piano notes to the point that, with the optimal choice of amplifier (see later), it was no longer a concern.
I ended up with the speakers farther apart than is usual in my room, which gave the smoothest integration of their balance through the lower midrange. This done, I fitted the supplied carpet-piercing spikes to the PSBs' bases and toed the speakers in to the listening position, which gave the best high-treble balance. I auditioned the speakers without their grilles: not only did I prefer the Synchrony One's appearance au naturel, I needed the little bit of extra top-octave energy that they produced without the grilles. The PSB's top two octaves then sounded clean and silky, with sufficient "air." I settled back for some serious listening.
I've been listening a lot of late to Smetana's tone poem Má Vlast, with Sir Colin Davis conducting the London Symphony Orchestra (SACD, LSO Live LSO0516). Recorded in concert in London's Barbican—one of my least favorite halls—the sound is a little on the dry side. However, from the resonant harp intro of the first movement through each string entry, each instrumental choir was delicately delineated in space, and every instrumental tone color was presented without coloration or undue emphasis. This speaker was also a natural for showing off that masterpiece of orchestration, Benjamin Britten's The Young Person's Guide to the Orchestra. My longtime favorite recording is with the composer conducting the LSO in London's Kingsway Hall (reissued on CD as Decca 417 509-2 or JVC XRCD 0226-2), but this 1963 recording sounded a bit too brash through the PSBs. A modern recording, of Paavo Järvi conducting the Cincinnati Symphony Orchestra (SACD, Telarc SACD-60660), sounded very much more natural at high frequencies, and had much the same weight and impact in the bass as the English performance.
The top octaves sounded smooth to me on this Telarc SACD—the delicately brushed triangle at the end of the final variation before the fugue was beautifully resolved, without sounding spotlit—but Erick Lichte was less tolerant than I of the PSB's performance in this region. However, in the "Measurements" sidebar accompanying this review, I wonder if he was reacting instead to the small response peak between 16 and 18kHz, which, unlike me, he could hear. The height of this peak is not affected by the perforated-metal grille, which proved to be transparent other than suppressing the speaker's output by a couple of dB between 9 and 16kHz. Even so, at the end of the mixing sessions we listened to one of my 2008 "Records To Die For," violinist Hilary Hahn performing Vaughan Williams' song of serenity, A Lark Ascending (SACD, Deutsche Grammophon 28947-48732-6), with nary a complaint from either of us.
The Synchrony One really shone with classical orchestral music, in part because its slightly warm upper bass and extended low bass gave the sound a firm underpinning. The double basses on the Telarc Britten SACD had the optimal combination of attack and weight to their tone. This speaker did go surprisingly low in the bass, considering its relatively small stature. When I listened to the 1/3-octave warble tones on my Editor's Choice (CD, Stereophile STPH016-2), the Synchrony One gave full measure down to the 25Hz band, with only the 20Hz warble inaudible. The half-step–spaced tonebursts on the same CD were reproduced cleanly and evenly from the lowest frequency, 32Hz, with little sign of doubling in the lowest two octaves and without undue emphasis on any specific note. There was also a commendable lack of wind noise from the flared ports, even at high levels.
Both the dual-mono pink noise and the in-phase bass-guitar tracks on Editor's Choice were reproduced as they should be: as narrow, central images without any frequencies splashing to the sides. With true stereo recordings, such as the Gershwin Prelude arrangements on Editor's Choice, there was no sense of images being localized at the speaker positions. Instead, individual instrumental images were precisely and solidly located in the plane between and behind the speakers. And when out-of-phase information was present in the recording, such as some of the effects on Trentemøller's album of chill-out music, The Last Resort (Pokerflat PFRCD18), these wrapped around to the sides in a stable, nonphasey manner.
Not only was the PSBs' stereo imaging stable, precise, and accurate, but throughout my auditioning of the Synchrony Ones I kept getting the feeling that I could hear farther into the soundstage that I had been used to. The timpani and the xylophone in the percussion variation of the Cincinnati Britten recording were set unambiguously behind the orchestra's woodwind and string choirs. This was not because the speakers were suppressing mid-treble energy, a not-uncommon means for a speaker designer to fake the impression of image depth—the PSBs were, if anything, a little hot in this region. Instead, there was such an absence of spuriae that recorded detail was more readily perceived.
But, as I said, this superb retrieval of recorded detail was accompanied by a slight lift in the presence region. This was not nearly so much as to add brightness to the balance, but voices were presented as being more forward in the mix. With the Cantus mixes Erick and I were working on, we felt we had to slightly reduce the level of the closer-sounding cardioid mikes in the mix to compensate for the more distant-sounding omnis. With recordings that are themselves overcooked in the highs—Bruce Springsteen's dreadful-sounding Seeger Sessions, for example (DualDisc, Columbia 82876 82867-2)—it all became a bit too much in-your-face. But with more sensibly balanced rock recordings, such as So Real, the Jeff Buckley compilation released on the 10th anniversary of the singer's death (CD, Columbia/Legacy), the PSBs effectively drew forth the music from the mix.
For this reason, the Synchrony One proved a better match to the warmer-sounding Mark Levinson No.380S preamp and No.33H power amps than the cooler Parasound combination of Halo JC 2 and Halo JC 1s, despite the Levinsons fattening up the midbass. Stereophile's latest CD, a reissue of Robert Silverman performing the two Rachmaninoff piano sonatas (STPH019-2), now sounded a bit too plummy, even with the bottom ports plugged. I ended up using the Mark Levinson No.380S preamp with the Halo JC 1 amplifiers, which gave the optimal top-to-bottom balance with the PSBs.
As I finish writing this report, I'm listening to the provisional 24-bit/88.2kHz mix Erick and I did of Cantus performing Lux aurumque (Golden Light), Eric Whitacre's 2001 setting of a poem by Edward Esch translated into Latin by Charles Anthony Silvestri. Whitacre constructs patterns of tone clusters that slowly move stepwise, leaving suspensions that you think will clash yet sound exquisitely tonal. Each of the nine singers was clearly and precisely positioned in space by the PSBs, with the deliciously warm reverberation of the Great Hall of Goshen College reinforcing the effect of the suspended notes in the score. And when, on the music's final page, the work modulates—finally—to the major, with the basses rocking back and forth between low C-sharps and D-sharps under a long-held high G-sharp from the tenors (who faced away from the mikes for this passage, in order to light up the hall with sound), the superbly neutral midrange and the low-frequency clarity of the Synchrony Ones filled my room with shimmering harmonies. Ah. It's hard to see how it could get much better.
Summations
The last two speakers I reviewed, the Sonus Faber Cremona Elipsa (December 2007) and the KEF Reference 207/2 (February 2008), each cost around $20,000/pair. As much as I was impressed by those highfliers, PSB's Synchrony One reached almost as high for just $4500/pair. Its slightly forward low treble will work better with laid-back amplification and sources, and its warmish midbass region will require that care be taken with room placement and system matching. But when everything is optimally set up, the Synchrony One offers surprisingly deep bass for a relatively small speaker; a neutral, uncolored midrange; smooth, grain-free highs; and superbly stable and accurate stereo imaging. It is also superbly finished and looks beautiful. Highly recommended. And when you consider the price, very highly recommended.
