Wilson Audio Specialties Duette loudspeaker
I had had it in the back of my mind for some time to try to hear the Wilson Duette, if only because celebrated classical recording engineer Tony Faulkner had, some time ago, shared with me his opinion that the Duette's simpler crossover made it the most coherent speaker in Wilson's line. Faulkner told me that when a cramped recording venue makes it impossible for him to use his favorite Quad electrostatic speakers for monitoring, he uses Duettes.
In a recent e-mail, Faulkner elaborated on the benefits of two-way speakers in general and the Duette in particular, saying that most three-ways fail at reproducing certain instruments, such as violas and trombones, through those speakers' crossover regions. His worst-case scenario is a three-way speaker whose crossover separates a singer's chest sound from his or her head sound. Faulkner praised the Duette's integration and musical balance.
Despite its having been launched in 2005, the Duette is Wilson's "invisible" loudspeaker. Perhaps the main reason is that the model immediately above it in price, the excellent Sophia Series 3, a floorstanding three-way, costs only $4000 more per pair, and only $2205 more if you order the Duettes with their dedicated stands. (Art Dudley covered the Sophia 3 in the February 2011 issue.) I assume that many people who don't need the Duette's adaptability to difficult listening environments will just open their wallets a little wider and buy the Sophia 3, which at first blush does appear to be the better value for money.
The Duette is large for a stand-mounted two-way. Its 18.4" height and 9.4" width might not be that unusual, but its 13.75" depth and its weight of 39 lbs are. Furthermore, the Duette's crossover is external, housed in a separate, quite handsome enclosure of painted metal, with provision at the rear for changing the value of the tweeter's resistor. The crossover box alone weighs 19 lbs. The two sets of binding posts on the Duette's rear panel connect to the external crossover's woofer and tweeter terminals with one of the supplied umbilical cables.
The Duette was designed to be used in nonoptimal placements, such as on a credenza or mantel, or in a bookcase or built-in cabinet. (Although Wilson offers a "rough-out kit" for custom cabinetry, I can't imagine using the Duette as an in-wall loudspeaker; it's far too deep and heavy.) The Duette's frequency response can be tailored to different environments by changing the value of the tweeter resistor. Counterintuitively, bookcase placement calls for a lower-value tweeter resistor, and therefore higher tweeter level. This is to complement the benefit gained by the bass from near-boundary reinforcement.
The Duette's instruction manual (available online) gives complete guidance for varying setups. All necessary parts are included with the speaker; you don't have to special-order what you might need. (Use of non-Wilson cables to connect the external crossover to the Duette voids the warranty; the precise inductance of the umbilical is part of the crossover design.)
The Duette's woofer cone is 8" in diameter, and Wilson claims for it a maximum excursion of 1.5"that's huge. The Duette's tweeter, a 1" dome of doped silk, is centered over the woofer. Wilson claims for the Duette a sensitivity of 90dB/W/m/kHz, a nominal impedance of 4 ohms, a minimum impedance of 3.96 ohms at 3.1kHz, and recommends at least 20Wpc of amplification. However, Peter McGrath told me that in order to get the Duette's full measure of bass performance, a solid-state amplifier of 100400Wpc should be considered, depending on the listening environment.
The claimed average frequency response in-room is impressive for a stand-mounted two-way: 30Hz25kHz, ±3dB. I don't find this hard to believe, for two reasons. First, at 50.24 square inches of frontal area, the Duette's 8" woofer is 51% larger than a 6.5" woofer's 33.14 square inches. Second, the Duette's cabinet has an external volume of 2372 cubic inches. To take at random a well-regarded, 6.5" two-way from Stereophile's 2012 Buyer's Guide, PSB's Image B6 has a total displacement of 1146.6 cubic inchesless than half the size of the Duette's cabinet.
Peter McGrath told me that the Duette measures flat at 36Hz in-room. My yardstick has long been that if a loudspeaker is flat at 41Hz (low E on an electric bass guitar), it should have enough bass for most music, the exceptions being Romantic works for full orchestra, Romantic works for grand piano, and full-range pipe organ.
The Duette is a rear-ported design rather than a sealed design such as Aerial Acoustics' 5B, which John Atkinson and I reported on in the June and November 2009 issues, or ATC's SCM 11, which I wrote about in December 2009. Therefore, one would expect that once the Duette's bass does begin to roll off, it does so twice as fast as would a speaker with a sealed box. The Duette's port is about 3" in diameter, machined from metal, and held in by screws. No pop-in plastic pipes for Wilson!
Wide dispersion is usually a principal design consideration for a modern loudspeaker. However, given that the Duette is more likely to be built into a cabinet or placed on a shelf than set out in the room on stands, one of Wilson's goals for the design was narrow dispersion, in order to minimize early reflections from nearby surfaces. Most of the front baffle area under the grille is covered in black felt; the tweeter is surrounded by a sunburst of felt with a sawtooth or pinked inner edge. I assume that all of these measures are intended to limit dispersion.
The Duette comes with small, dimpled pucks of machined metal and sets of spikes in three different lengths, to couple the speaker to the stand's top plate. The pucks fit into machined recesses, and the spikes attach magnetically to the Duette's bottom or side. The different lengths of spike allow the speaker to be tilted, if needed, for proper integration of the drivers' outputs. Wilson offers a handsome stand of the optimal height (about 25", with adjustable bottom spikes), with a space at the bottom rear to hold the crossover, for another $1795/pair. The stand's top and bottom plates are machined of black-anodized metal, while the pillar is made of the proprietary mineral-loaded composite material from which Wilson makes speaker cabinets and braces. The stand can be ordered with its pillar in the same paint color as the Duette.