How do you follow an act like the Elac Debut B5? The pint-size, two-way compact simply crushed it with its big, hearty sound and puny $229 price tag (reviewed in Issue 260). In a rare convergence of enthusiasms, it won the hearts of high-enders and mainstreamers alike. However, for Elac’s VP of Engineering Andrew Jones, a longtime advocate of concentric drivers (look no further than his work at KEF and Pioneer/TAD, for examples) there was unfinished business. Hence, Uni-Fi: a new line of affordable Elac loudspeakers, including the UB5 compact under review here, plus a UC5 center-channel, and the floorstanding UF5. The UB5 features concentric midrange/tweeter transducers in a three-way driver configuration.
The UB5 is a stand-mounted compact with a bass-reflex design that uses a rear-firing dual-flared port. Just shy of thirteen inches tall, it’s easily one of the smallest three-ways ever made and its compact size is almost entirely owed to the concentric driver’s remarkable space-saving properties. Also known as a coincident (or archaically as a coaxial) driver, it’s a sophisticated design that insets a one-inch soft-dome tweeter at the center of a four-inch aluminum midrange. Its crossover point is 2.7kHz. Also specially designed for the Uni-Fi line is the five-inch aluminum woofer. Apart from some minor trim changes, the UB5 is a near-spitting image of the B5 with some classy touches added, such as premium binding posts and the magnetically attached fabric grille. The result is a sturdy MDF-braced enclosure that adds a mere couple of inches in depth. Like the Debut line, it’s nicely finished in black brushed vinyl.
In a conversation about the UB5’s conception, Jones said, “The enclosure is a development from the B5. It wasn’t fully planned when I did the B5, but when starting work on the UB5 it made sense to use the same frontal dimensions so that I could use the same grille tool. I changed the logo and changed from push-pins to magnetic fastening to differentiate it from the B5. To get the required volume and to compensate for the space taken up by the separate midrange chamber, I added depth to the enclosure. I chose to make the midrange enclosure part of the cabinet construction, rather than a tube on the back of the midrange, so that it could add bracing to the cabinet. In addition I added an extra brace, all to help stiffen the cabinet.”
As for the change from the B5’s woven mid/bass to the UB5’s aluminum bass driver, Jones explained, “The B5 used woven aramid because it was a two-way system, so the bass driver had to perform double-duty as bass and midrange. Once I went to a three-way system I was free to use a material that could be optimized specifically for bass reproduction. This includes having the correct mass, and being able to get the required stiffness without having to worry about cone breakup messing with the midrange. The bass driver motor structure was then fully optimized to give me better bass performance than was possible with the B5. Likewise, the midrange could be optimized as just a midrange driver, and because of the cone size and voice-coil size I could get the breakup-mode to be a high 8kHz (by contrast, the TAD beryllium driver, although larger, was only marginally higher at 9kHz).”
Sonically, if you loved the B5—and any self-respecting audiophile should—you’re gonna love the UB5 just a little more, and maybe a lot more. The UB5 is the B5 gone to finishing school. It boasts fewer box colorations and smoother, more accurate tonality, and is emboldened by the greater output and dynamics that befit a dedicated three-way design. It’s still a bit dry in the treble but nicely detailed without being offensive. Basically, it’s everything the B5 already is plus all the extras Elac could stuff in while still graduating with a $499 sticker. In musical character, the UB5’s voice will be familiar to all who have encountered the B5 (you mean you don’t already own a few pairs?), or the Pioneer SP-BS22, or even the state-of-the-art TAD CR-1. The $42k TAD? No, I’m not being glib. All these examples share (within reason) a similar overall voice—one that is anchored by a balanced and dynamic midrange, a forward energy (no suckouts), and a persuasive lower midrange and upper bass.