DALI Euphonia surround speaker system
A Blank Canvas
To make an impression in the crowded marketplace of home theater speakers, a manufacturer must create a product that marries high performance to high style. DALI's Euphonia speaker system does just that. Every speaker in the line boasts not only a bold shape, but new technological twists on basic loudspeaker design.
Except for the AS 2 subwoofer, all Euphonia speakers are built around a dual-tweeter module comprising soft-dome and ribbon tweeters. The tweeters work together to create a high-frequency transducer system with better power handling and more even dispersion than a single driver can achieve. The ribbon makes it possible for the Euphonia's upper-frequency limit to extend to a specified 40kHz, while the dome's linearity in its lower range permits smooth integration with midrange drivers. Both tweeters use neo-dymium magnets so they can be placed very close to one another, which makes it easier to integrate the two drivers' outputs into a sonically unified whole.
Euphonia speakers have custom-made 6.5-inch mid-woofer cones made from a composite of wood and paper fibers. Unlike conventional paper-pulp cones, these contain unusually long wood fibers in a carefully measured proportion to help control internal resonances. A light outer coating and optimized shape also reduce spurious resonances, while ensuring that the cones are as light and stiff as possible. Along with its low mass, the driver is extremely wideband, which means that the crossover frequencies can be set well within its region of optimum linearity. Using wideband drivers also ensures that phase shift near the crossover points can be kept to a minimum.
The design of the Euphonia speakers' crossovers also reduces phase shift and harmonic distortion. The DALI designers believe that the drive units and crossover networks are not separate entities but parts of a complete system. All crossover components are hardwired to one another without any circuit boards, so that leads can be short and lose as little signal strength as possible. The components are then secured to a mounting plate with glue and screws, and the entire crossover network is housed in its own chamber, isolated from the rest of the speaker enclosure.
The phrase box speaker brings to mind a cabinet with little personality or style. Technically, the DALIs are boxes, but the shapes of those boxes are anything but square. No surface is flat. Besides giving the Euphonias a decidedly stylish, unboxy appearance, sonic reasons dictate the speakers' nontraditional shapes: Curved surfaces reduce diffraction and cabinet resonances. The internal chambers feature proprietary cabinet walls designed to break up and disperse resonances. The cabinets' inner walls are curved, with numerous V-shaped grooves filled with special adhesive material. This combination of curves and grooves makes the inner cabinets more inert, reducing mechanical resonances. Multiple internal braces throughout add rigidity to the MDF enclosures.
The Euphonia front baffles are sandwich designs: a 16mm-thick panel bonded to a 22mm-thick panel. The combination forms an extremely rigid surface on which to mount drivers, and the baffle's thickness means DALI can mill out cavities around the drivers to permit an unrestricted flow of air around the backs of the cones.
DALI spent a great deal of time and effort to find Alpi, a spectacular new veneer. Alpi isn't a recently discovered species of wood, but a new process in which layers of ordinary-looking woods are kept under high pressure in a specialized machine for several months, after which they come out as stunning veneers. Although the Alpi process is expensive and time-consuming, the result seems well worth the added cost. The Euphonia AS 2 subwoofer's enclosure is especially entrancing, sparkling with high style. For spaces in which the Euphonias must coexist with cats, dogs, and small humans, detachable, low-resonance, laminated grilles of metal and polymer can finish off the speakers' suave exteriors.
Even the Euphonia speaker stands display fresh thinking. Instead of ordinary wooden platforms, the Euphonias' bases are made of a compound of crushed granite and polymer precisely molded into shape. The result is rigid, high-mass, and strikingly attractive. You can install pointed or rounded spikes under the bases, or use DALI's new, proprietary absorptive material to get a solid, mechanically grounded connection with your floor.
Persistence of Vision
The DALI Euphonia system consists of four different speakers: the MS 4 floorstanding main speaker, the CS 4 center, the RS 3 rear, and the AS 2 powered subwoofer. While they share many characteristics, each speaker has been designed to fulfill a unique role. Some audio experts feel that using the same unit for all five surround positions maximizes audio consistency, but an audio designer can optimize each speaker's performance and deliver greater overall system value by using unique cabinet shapes and driver arrays for each intended location.
The MS 4 front speaker has two 6.5-inch woofers and Euphonia's dual-tweeter module. One woofer handles only low frequencies; the other takes care of the midrange until it crosses over to the tweeters. This configuration provides greater power-handling ability and improves midrange dispersion. This is called a "21/2-way" system: although the MS 4 has three drivers—woofer, mid-woofer, and tweeter—it has only a single main crossover point, at 3kHz, between the midrange and tweeter. With a large rear port behind each woofer, the MS 4 qualifies as a bass-reflex enclosure. And with its provisions for biwiring via large, knurled, gold-plated speaker terminals, the MS 4 shows a high level of attention paid to both engineering and aesthetic details.
The CS 4 dedicated center-channel has the same driver complement as the MS 4, but in a different arrangement in a differently shaped cabinet. DALI's designers created the CS 4 to be used either atop or underneath a direct-view monitor, or under a screen. Its dedicated stand allows it to be aimed up or down, or placed directly atop the AS 2 subwoofer. Unlike the MS 4, whose two mid-woofer drivers are right next to each other, the CS 4's drivers are on either side of the central tweeter module, which is rotated so that the CS 4's and MS 4's tweeters have the same vertical alignment. Because of its different shape and placement requirements, the CS 4's voicing and efficiency are different from the MS 4's. With smaller rear reflex ports and interior volume, the CS 4's bass extends only to 45Hz rather than to 33Hz. The CS 4's crossover point is also different, at 2.4kHz instead of 3kHz. All of these changes were made to ensure that, in real-world home theaters, the CS 4's and MS 4's overall timbres would closely match.
The RS 3 rear speaker is a small-footprint 2-way design with a single 6.5-inch midrange woofer and the Euphonia tweeter module. Its sealed cabinet reduces the RS 3's bass extension, but since it's designed to be placed near an intersection of wall and ceiling, where a room's bass resonances are easily excited, having bass extension to only 64Hz works to its advantage. A special wall bracket pivots horizontally and vertically, allowing the RS 3 to be precisely angled to produce optimal dispersion at the primary listening position. Some manufacturers' rear speakers show signs of not having been built to as high a standard as the rest of the system, but the RS 3 uses the same audiophile-grade speaker terminals, hand-assembled and hardwired crossovers, and premium cabinet veneers as its larger siblings.
The AS 2 powered subwoofer shows the most radical physical departure from conventional speaker design: It looks almost like a large teardrop. A pair of 12-inch, long-throw woofers, one at each end of the enclosure, operate in phase but in opposite directions, largely neutralizing the physical effect of driver motion on the cabinet, leaving it inert and motionless. Combining a compact dual-chamber sealed box with mild active equalization, the AS 2 uses a 650W RMS class-D amplifier to achieve low bass down to 25Hz. The AS 2 has controls for overall volume level, lowpass frequency points, and phase settings, as well as single-ended RCA connections for stereo inputs and stereo outputs.
Setting up the DALI Euphonias required three healthy adults: two to do the heavy lifting and moving, and one reviewer to watch appreciatively. Unlike most front speakers, which require some toe-in to directly face the center listening position, DALI recommends that the MS 4s be placed to fire directly forward, with no toe-in at all. With the help of some large AudioQuest Sorbothane pucks to prevent slippage and retain the proper angle, the CS 4 center fit comfortably atop my Proton 331 direct-view monitor.
Instead of positioning the AS 2 subwoofer directly under the CS 4 or the Proton, I decreed that it be placed near a corner. Its unique shape meant that the AS 2 needed to be farther out in the room than a usual box-shaped sub would have been, but its final location was not obtrusive. Placing the AS 2 directly under the CS 4, as DALI shows in their brochures and website, may not always be the wisest choice; the best location for the center channel will only rarely be the best place for a subwoofer.
Art and Commerce
Usually, speakers that sound fine when played softly begin to come unglued when driven hard. Conversely, speakers that handle crushing crescendos with aplomb often sound lackluster when fed less power. In promotional brochures, DALI stresses the importance of making speakers that can sound good at both low and high volume levels.
The Euphonia speakers achieved a rare dynamic balance, performing optimally regardless of the amount of current pulsing through their drivers. Even though the Euphonias aren't tremendously efficient, at only 88dB/W/m, they're so easy to drive that most amplifiers rated at over 100Wpc RMS will be able to produce THX-certified sound-pressure levels with little effort. This translates to cleaner, stress-free sound.
Along with a lack of stress at high SPLs, the Euphonia system captured the entire dynamic range of any source I threw at it. Whether it was my own live concert recordings or the latest James Bond explosion-fest, everything from the quietest whispers to the loudest bombast had the right relative volume level and proper articulation.