The next time that audiophile catalog lands in your mailbox—you know, the one that’s been coming every month or so ever since you bought a gallon of record cleaning fluid sometime during the second Clinton administration—take a close look at the photos used to show off the equipment to its best advantage. A Spartan turntable sits on a tastefully distressed wood-plank table with three potted cacti looking on admiringly. A top-quality surround-sound system is displayed in a living room on a well-maintained oak floor with glimpses of an expensive-looking Persian rug and a contemporary Italian glass coffee table in the frame. A sleek equipment rack holding thousands of dollars worth of gear sits beneath an abstract watercolor. The presentation is intended to communicate that owning good audio gear demonstrates an appreciation for the finer things in life. But do the hypothetical inhabitants of these refined spaces only look and not listen? I ask because there’s not a cable in sight.
The idea of a wireless audio system has a lot of appeal, and not just because of aesthetic considerations. There’s the chance for a designer to optimally match amplification to a loudspeaker’s drivers and enclosure. There’s all the assets and angst spared by not having to deal with interconnects and speaker cables. Although most active loudspeakers are smaller models intended for desktop or studio use, the product class has been burgeoning lately, and there have been some recent high-profile successes with full-range models aimed at the audiophile market. Bruno Putzeys’ Kii Three, the Gayle Sanders’ Eikon, and several others have joined offerings from trailblazer Meridian Audio. In the loudspeaker game since 1983, Denmark’s Dali—that’s Danish Audiophile Loudspeaker Industries—has decided to commit resources to this approach, as well.
Dali introduced two powered loudspeakers in 2017, the Callisto 2 and Callisto 6. The bookshelf Rubicon 2 C and the Rubicon 6 C floorstander considered here are the first instances of DALI taking an existing product (the Rubicon 6, at $5499 per pair, debuted in 2014) and building in the wireless technology of the Callistos. The Rubicon 6 C, with the DALI Sound Hub that serves as a streaming preamplifier connecting wirelessly to the loudspeakers, retails for a smidge under $8800.
The DALI Rubicon 6 C loudspeakers are handsome, if conventional-appearing rectangular boxes measuring 7.9″ (W) x 39.1″ (H) x 15.0″ (D). Each speaker weighs in at 45.8 pounds. The 6 C is a 2½-way bass-reflex system, with both its hybrid tweeter and two 6.5″ mid/bass drivers built by DALI in Denmark using European-manufactured parts. The high-frequency unit combines a 1″ soft dome, featuring a copper-clad aluminum voice coil, and a wide-dispersion magnetostatic ribbon. The complete tweeter assembly functions from about 2500Hz to beyond 30kHz. The mid/woofer has a wood-fiber diaphragm that’s both light and rigid, possessing an uneven surface that assures more ideal pistonic movement of the membrane. Perhaps the driver’s most significant design element is the Soft Magnetic Compound (SMC) used to replace a key iron part of the magnet structure. As explained to me by DALI CEO Lars Worre, SMC is “a pulverized material consisting of very small iron particles, which are individually coated so that when you press them together into a form, none of the particles will—electrically—be in contact. Consequentially, there will be no electrical conductivity: SMC is around ten thousand times less electrically conductive than iron but has the same excellent abilities to conduct magnetism.” DALI manufactures its mid/bass driver’s pole piece entirely from SMC, enclosing it in a slitted copper cap. A measurable consequence of this design is the virtual elimination of hysteresis, a phenomenon resulting from the asymmetry of the magnetization/demagnetization process that introduces distortion-causing resistance to the voice coil. Despite that, by necessity the SMC pole piece is located close to the magnet gap. Worre said, “We don’t lose energy to the surrounding iron materials, and the result is a dramatic reduction in distortion, particularly with odd-order harmonics.”
The Rubicon’s enclosure is fabricated from MDF, with the drivers attached directly to a one-inch-thick front baffle. Strategic internal bracing is used to reduce standing waves and resonances. There are three available finishes, all priced the same—black and white gloss lacquer and walnut veneer. The mid/bass drivers are situated in two equal-sized internal compartments, each with its own rear-firing port tuned to 36.5Hz. The 6 C employs two identical, 250W, self-oscillating, “Eigentakt” Class D amplifiers; one powers the tweeter unit and the other the two mid/bass drivers. The crossover is a hybrid of active DSP filtering and passive analog topology with hand-off frequencies of 800Hz (bottom to top midrange/bass driver), 2.6kHz (top mid/bass to dome tweeter) and 14kHz (dome to ribbon.) The system’s DAC lives in the loudspeaker, a Burr-Brown 1796 chipset. This is a PCM-only device, so those devoted to native DSD may be disappointed. Lars Worre wasn’t exactly sympathetic. “From a radio transmission point of view, we could have quite easily decided to transfer a DSD stream with oversampling corresponding to the commonly used 2.8MHz version,” he told me. “But it would have called for another platform for D-to-A conversion in the speaker. We decided to stay with the rather good-sounding 24-bit/96kHz basic format, as the use of true DSD sources is so commercially marginalized that we believe it will never, in reality, be an issue for actual customers.”
On the rear of each Rubicon 6 C, where you’d expect to find the binding posts, are an AC connector for the supplied power cord, a rocker-type power switch, a USB service port, and an RCA input to allow the loudspeaker to get line-level input from an external preamp or processor instead of DALI’s wireless Sound Hub. Above these connections is a small screen that illuminates to guide the wireless pairing process, and above that is the critical Link/Connect button. Each 6 C is provided with two metal bars that fit neatly into recesses on the speaker’s bottom to create a stabilizing outrigger structure. Four supplied spikes can be threaded into the bars; rubber bumpers are an alternative. A single grille attaches with plastic pins to cover all the drivers. Like most loudspeaker grilles, it’s not completely transparent sonically, and should be removed for critical listening—though the same party who OK’d the speakers’ admission to a shared living space because of the absence of cables may balk at the prospect of exposed drivers. So, it goes.