“What does that speaker sound like?”
It’s such a common question among audiophiles that we never stop to think about what it means. When asking that question, we expect a capsule description of the speaker’s strengths and weaknesses, accompanied by an assessment of its overall character and quality.
But what we are really asking is: “In what specific ways does that loudspeaker distort the musical signal, and what is our perception of that distortion?”
We frequently ask what a speaker “sounds like” because every speaker changes the sound in its own specific way. The ideal speaker would be a perfectly colorless, transparent window on the amplifier’s output signal. In the real world, a speaker’s “sound” is the sum total of all the ways, large and small, that the speaker deviates from this transparent-window model. Every loudspeaker, no matter how much it costs, fails to perfectly create an acoustic waveform that is a precise replica of the electrical input signal driving it.
These deviations from perfection can be additive or subtractive. The additive distortions include things like excessive treble, bass overhang, and harmonic distortion, to name a few. A list of subtractive distortions could include an inability to reproduce the lowermost octave, compression of dynamic peaks, and a slowing of leading-edge transients. We also call these “sins of commission” and “sins of omission.” As a rule, sins of commission are far more detrimental to musical enjoyment than sins of omission.
You can think of a speaker’s “sound” as its sonic fingerprint overlaid on every instrument on every piece of music you listen to. You hear not just the music, but the loudspeaker’s flaws inextricably woven into the music’s fabric. These distortions are integral to the music-listening experience, and thus define our perception of what a speaker “sounds like.”
Which brings me to Wilson Benesch’s new Eminence, a $235,000 statement-level floorstander designed to compete at the highest levels of the high end. After living with this speaker for the past three months, I will say right at the outset that, with one caveat, the Eminence is in many ways the least colored and lowest distortion speaker I’ve heard. It is a step forward in realizing the ideal of a transparent window on the music. This transparency to the source isn’t limited to transparency in the usual sense of the word—the “see-through” quality associated with soundstaging—but also transparency to the music’s dynamics, pitch, timing, timbre, and most importantly, expression.
This towering (literally and figuratively) achievement in loudspeaker design wasn’t realized overnight. The Eminence is the culmination of 25 years of intensive R&D, often in collaboration with world-class experts and academics in tertiary fields. It is packed with innovative engineering, including extensive use of carbon fiber in the enclosure. Wilson Benesch was the first company to successfully use carbon fiber in an audio product (a turntable, in 1991) and has since pioneered the use of that material in audio applications (see sidebar). The company makes, in-house, virtually every part of the Eminence, including the drivers, the machined aluminum parts, and even the carbon-fiber enclosure. Moreover, the fundamental design principles behind the Eminence can trace their roots back to Wilson Benesch’s first loudspeaker.
The Eminence’s strikingly different shape and unusual driver array reflect the engineering behind it. Standing six-and-a-half feet tall but with a baffle just 7.5" wide at the front and wearing an oddly shaped geometric “hat,” the Eminence stands out from the typical rectangular shape of most speakers. Adding to the idiosyncratic appearance, the four lowermost drivers on the front baffle are mounted backwards, with the magnets facing out into the room. The enclosure narrows toward the rear in a boat-tail shape, and the whole thing is bolted to a massive aluminum plate that is in turn supported by four adjustable shafts that terminate in four bearing cups that rest on the floor.
The ten-driver Eminence is a two-and-a-half-way design. You can see in Fig.1 that the lower two “backward-facing” drivers in the baffle are mated to two identical 7" drivers inside the cabinet in an isobaric configuration (we’ll address this design element in more detail later). The next two drivers up the baffle handle the lower bass. Just above the upper-most backward-facing woofer is a 7" midrange, and then the tweeter. The top two 7" drivers handle the upper bass. As you can see in Fig.1, each driver array is mounted in its own sub-enclosure within the cabinet. All the sub-enclosures are sealed, except for the one housing the isobaric woofer array, which is ported out the bottom of the cabinet. Two pairs of binding posts are provided for bi-wiring.