Wilson Audio Specialties CUB loudspeaker
Wilson loudspeakers are not typically products we can all aspire to own. They have always been price-no-object designs. Not to mention the fact that the looks of all Wilson speakers have, up till now, inspired either "Love it!" or "Not in my living room!" reactions. They're astonishingly well made and beautifully finished, to be certain, but definitely from the "high-tech" school of design.
Thus the CUB. With more and more high-end loudspeakers pushing five-figure price tags, the cost of a pair of CUBs in today's market, if not exactly petty cash, raises only the most tentative of eyebrows. And the CUB's appearance is almost conventional: a rectangular, stand-mounted box with three forward-radiating drivers. When I reviewed the CUB in a home-theater context for the January 1998 issue Stereophile Guide to Home Theater (an application that must have been in the mind of the designer, and for which the loudspeaker is very well suited), Wilson took exception to my characterization of the loudspeaker's shape as "conventional." Well, compared to their other loudspeakers, it is. But since it's a Wilson, it doesn't take more than a few seconds to see that there is really very little else about the CUB that's "conventional."
The CUB—which stands for Center Unitized Bass—utilizes a pair of 6.5" treated-paper cone woofers (made by SEAS) and an inverted metal-dome tweeter. The woofers appear to be similar to the midrange driver in the Wilson WITT, which itself harks back to the woofer in the original WATT (since changed). It's apparent that Dave Wilson likes this woofer, and, judging from the success of those earlier loudspeakers, his confidence is well placed. The tweeter is an inverted titanium-dome design coated with titanium dioxide, the latter said to effectively damp the resonances that often afflict metal-dome tweeters. Focal, the manufacturer of the tweeter, calls this coating material Tioxid.
Each of the two woofers is mounted on its own separate sub-baffle, both of which sit just forward of the centrally mounted tweeter. These sub-baffles, made of an ultra-high-density composite identical to that used in the Wilson X-1 Grand SLAMM, are tapered in on the sides facing the tweeter and finished in a high-gloss black that gives the loudspeaker a unique, elegant appearance. But I always have reservations about cabinet protrusions that might cause diffraction, even though here there are some fairly thin foam pads in the area of the tweeter to minimize this effect. The only justification for such a setback tweeter configuration is time alignment, and only the measurements and the listening will tell us if the effort has provided more benefits than liabilities.
Connection to the CUB is via a single pair of high-quality terminals. These are unusual in that they may only be used with spade lugs or bare wires—banana plugs need not apply. (Wilson says this reflects current European regulations.) The lack of a bi-wiring option is common to Wilson Audio loudspeakers, but it's not a cost-saving measure; Wilson is apparently not a proponent of bi-wiring, at least not for their own designs. One obvious benefit of this is that you can budget for a single "better" pair of loudspeaker cables rather than two cheaper ones. (Still, there's no guarantee that any specific set of more expensive cables will sound better.)
A pair of test points on the back of the CUB, labeled "Resistor Test Port High Frequency," are provided to diagnose tweeter problems. More specifically, if you measure approximately 1 ohm across the test points, all is well. If not, a resistive fuse in the tweeter circuit has apparently blown and service is required. (I measured 0.8 ohm across these points in our samples—well within the "normal" range.)
The CUB's rigidly braced and extremely solid cabinet is built of a combination of MDF and synthetic composite materials. And it weighs 75 lbs, so unless you spend a lot of time in the gym, you'll probably need help setting it up. Applying the old knuckle-rap test to the Cub's cabinet produced little result beyond sore knuckles. Protruding from the back of the cabinet, looking like transformers that have escaped from a high-powered amplifier, are two gray blocks—the electromagnetically shielded, encapsulated crossover networks.
A wide variety of standard and custom finishes is available; our CUB samples were finished in a gorgeous rosewood veneer so smooth and polished that my first reaction was "plastic laminate." But the corners revealed no signs of a laminate finish, with good reason: This real-wood veneer overlaid with a high-gloss lacquer reminds me of nothing less than the interior wood trim in a Mercedes. The finish is completely covered with a semitransparent film at the factory, which protects it from scratches in handling and transit. The film must be peeled off; Wilson recommends that it be left in place while you're finding the CUBs' proper positions. But it will leave marks on the finish if left on for an extended period; remove it as soon as setup is complete.
In my SGHT review, I remarked negatively on the shiny heads on the steel bolts used to fasten the CUB's drivers to its baffle. In a home-theater setup, this is a possible source of unwanted optical reflections, especially for those who may wish to place the loudspeakers behind a perforated screen. (I don't recommend this; there's no such thing as a screen sonically transparent enough to do full justice to loudspeakers of this caliber.) According to Wilson, they use stainless-steel bolts to eliminate the possibility of corrosion.
The foam grille that comes with the CUB is attractive, but the loudspeaker looks fine (to me) without it. More important, while the foam itself is reasonably transparent to sound, the plastic grille frame looks like it could be a source of diffraction.
The CUB's high sensitivity may make it attractive to those with low-powered tube amplifiers. Wilson denies that the loudspeaker was intended for that purpose; the company never uses such designs in their show demonstrations, sticking instead to both tube and solid-state amps of medium to high power. Nevertheless, the fact that these loudspeakers don't really need unusually high power certainly won't hurt their potential market base.
Evaluated as a full home-theater array for the Stereophile Guide to Home Theater review, five CUBs had an immediate, vivid presence that was unmistakable, and very recognizable as Wilson loudspeakers for anyone familiar with the brand. The midrange was clear and articulate. Dynamic contrasts were particularly well handled, and while the sound struck me as noticeably forward of neutral, I never found it to be in my face. There was an audible trace of nasality or cupped-hands coloration, but it was never obvious, and only present on a small cross-section of program material. Film dialog sounded as natural as the source allowed, and vocal music much the same.
To quote myself from that earlier review, listening to a home-theater array of Wilson CUBs was definitely a "Wow!" experience: Fed good program material, they shone. Fed a ragged signal, they had me reaching for the volume control. The Wilsons did not suffer lightly any over-the-top, bright, over-engineered soundtracks. (This does not describe all soundtracks, by the way.) And it's hardly surprising that the same unforgiving nature also made the CUB unhappy on poorly recorded music. The low treble did sound more prominent than the extreme top end; the price paid for the Wilson's immediacy and dynamic capability was a tendency for the sound to occasionally "bite" with forward, somewhat bright (but not poor) recordings. But in compensation, the sound was never "polite" or wishy-washy. The CUB sounded alive.
I also listened to a pair of CUBs in the music system as part of that prior review, and found that the sound differed somewhat from the home-theater experience—suggesting, not surprisingly, some not atypical room sensitivity in the loudspeakers. My home-theater and audio systems are in different, separate rooms, and the music room is the more highly damped of the two. There, the CUB's top end remained clean and open, though the overall sound warmed up a bit from what it had been in the home theater. (The comparison here is with the CUB's performance in the home-theater system on music, using simple music surround modes for two-channel material.) The bass in the music room was tight, punchy, and crisp. It was not exceptionally deep, but neither did the CUB sound thin. Soundstaging was superb.