Tower Speaker Reviews

Performance
Build Quality
Value

AT A GLANCE
Plus
Open, airy highs
Clean, tight bass
Big, generous soundstage
Minus
Setup takes patience for best results
Treble can be unforgiving

THE VERDICT
Careful trial and error with placement, and perhaps the addition of a good subwoofer for movies with crushing bass will be needed for getting the best out of the DALI Rubicons. But the best this system offers is compelling.

DALI (Danish Audiophile Loudspeaker Industries) isn’t new to this country, but it’s relatively new as overseas loudspeaker manufacturers go. The somewhat new Rubicon range sits near the top of the company’s U.S. product offerings, topped only by the Epicon series, which it is said to most closely share technology.

Description
Within the Rubicon line, the Rubicon 8 is the top model, with three 6.5-inch drivers, a 1-inch dome tweeter, and a planar magnetic supertweeter. All three woofers operate below 500 hertz. The bottom two gradually depart the picture above that, with the topmost woofer operating alone from 800 Hz to 2.5 kilohertz. The dome tweeter operates above that point, supplemented by the supertweeter crossing over at 14 kHz. DALI calls this arrangement a 2½ + ½ + ½ -way design.

The dome and supertweeter combination —it's technically a planar tweeter but is referred to as a ribbon—is a DALI specialty, used in many of the company’s designs. The top range of the dome tweeter is not rolled off but rather is left to taper off naturally. Like most dome tweeters it extends well up through the audible range. Meanwhile, the supertweeter’s high-pass filter is gradual enough to allow it to make a significant contribution well below its 14 kHz crossover point. The result is a region where both tweeters overlap and operate together. Dali explained the benefits to us thus:

"The ribbon tweeter is about 1 percent of the total output of a DALI speaker, giving the sound that little extra glisten and shimmer that a dome tweeter has a difficult time achieving. Using the dome in the lower part of the trebele allows it to focus on the area of sound that domes are best at. For this reason, the dome is slightly oversizd to improve its mix with the midrange, while making for a slight faster roll-off than average." The 6.5-inch woofers incorporate DALI’s SMC (soft magnetic compound) technology, which is said to significantly reduce hysteresis in the driver’s magnetic structure. Hysteresis can be a significant source of distortion.

The Rubicon 8 sports three rear-panel ports plus a pair of good-quality binding posts for biwiring or biamping, if desired. I left the shorting straps that connect these two sets of terminals in place and used a single cable run to each speaker. Spiked or rubber feet are also provided. I didn’t use the spikes—my speaker setup sits on a large rug covering spike-intolerant hardwood floors over a slab foundation.

Our review system also included three Rubicon LCRs—a pair for the surrounds and another for the center channel. The LCR consists of a single 6.5-inch SMC woofer and a dome/planar tweeter array similar to that found in the Rubicon 8s. This 2 + ½ -way design crosses over at 3.1 kHz and 14 kHz. The dual tweeter array is mounted on a circular module that can be rotated 90 degrees if you want to mount the cabinet horizontally. This involves removing four screws, reorienting the module, and refastening the screws (an operation best left to your dealer if you’re dangerous around screwdrivers). In addition to a single pair of binding posts, the back panel also has metal slots for a wall-mount option. In my setup, however, I used all of the LCRs, including the surrounds, freestanding. (Another system option today would be to replace the LCR at the center position with the Rubicon Vokal center speaker ($2,495), which debuted in January at CES but was not available at the time of my evaluation.)

Grilles are also included for all the speakers, but the honeycombed plastic structure supporting their grille cloths suggests that they’re less than acoustically benign. I normally don’t use grilles anyway, and I didn’t use these.

Setup
When I requested the Rubicons, there wasn’t a DALI subwoofer I felt was adequate to fill my large room. So I elected to request the system without a subwoofer. I did all of my music listening to the Rubicon 8s full range, and as we’ll see below, even in my large room they performed admirably down to at least 35 Hz. For home theater, they’ll get the job done without a subwoofer if your room is modest to average in size, your listening tastes run to reasonable volume levels, and the movies you prefer don’t demand much at the extreme bottom end. But I use higher volume levels for movies than for music, my listening space is open-concept with the acoustic challenges that implies, and the system must accommodate video material ranging from Downton Abbey to The Avengers. For movies I therefore used a (long discontinued) Revel B15 sub. And apart from a reduction in my pre/pro’s center-channel bass control to compensate for the center LCR’s near-floor positioning, no other equalization of any kind was used in the review.

Since we received the system, DALI has introduced a new subwoofer with a 14-inch driver and a 450-watt amplifier that looks the business—the SUB K-14F. You may wish to check into it if you want a DALI sub for the system (Sub K-14 F Whitepaper here).

The left and right Rubicon 8s were set up about 9 feet apart, with the back of the speakers a bit less than 4 feet from the wall behind them. The left speaker was 3.5 feet from the left side wall; the right speaker has no nearby side wall, as it sits next to a wall-sized opening leading to another part of the open concept space.

DALI recommends that their speakers fire straight into the room rather than being toed in. I tried this, but it can be a problem for off-center listeners in a home theater application. I settled on toeing in the 8s just enough so that their axes crossed behind my head as I sat in the center. This put me somewhat off axis of the speaker’s firing pattern for music. I tend to sit off to the side for movies (for reasons that may someday inspire a blog), and in that position was even more off axis to the 8s baffles (and more off axis to the far speaker than to the nearer one, though the DALIs’ wide dispersion made that a non-issue). I also tilted the Rubicon 8s forward slightly, since the center of the tweeter array was several inches above my seated ear height.

The LCR surrounds were set up behind the seating area and aimed toward the side walls to offer a bit more diffusion to the surround channels. I also found that when the center LCR was set up horizontally (and the tweeter module rotated accordingly), it sounded subtly different from left and right seats. I preferred the vertical setup. For that to work without blocking the fairly low flat- screen Ultra HDTV above it, however, I had to place the LCR on the floor and angled slightly upward.

Apart from an Integra DTC-9.8 surround processor, the system consisted of a Proceed AMP5 for the three front speakers and an Outlaw 750 amplifier for the surrounds. The sources were a Marantz UD7007 universal player for music and an Oppo BDP-105D for video. The Marantz was connected to the Integra with a coaxial digital cable and the Oppo via HDMI. The cables were an eclectic combination of non-current Cardas, Kimber, and Monster.