PSB Synchrony One

[Κώστας Φ.]

"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.

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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." -- John Atkinson


"The PSB Synchrony One offers superb measured performance, as I have come to expect of Paul Barton designs." -- John Atkinson

Full Review: Stereophile.com