B&W DM 602 Series 3 Surround Speaker System

The model designation "DM" might not sound like anything special, but it has a long history with B&W. Models such as the DM 6, fondly remembered by audiophiles as the "pregnant penguin," enjoyed a modest following in the 1970s, when then-small English speaker company Bowers & Wilkins was knocking out attendees at hi-fi show demonstrations. B&W is now, by most accounts, the biggest speaker company in the UK. Its model range has increased exponentially since those early days, but the DM prefix is still very much alive.

The DM 600 line doesn't go back quite as far as the company itself—it only seems to. In this new Series 3 generation, the DM 600 remains one of the biggest bargains in audio—at least judging from the system that was the subject of this review.

Ins and Outs
The two-way DM 602 S3 is the heart of the system we requested for review. It's the largest bookshelf model in the model lineup, which includes the smaller DM 600 S3 and DM 601 S3, plus three floorstanders and two other models that can function either as center- or main-channel speakers.

B&W has added some significant refinements to all the new models, many of them filtered down from the development work done for the company's flagship Nautilus line. As in the Series 2, the tweeter incorporates a tubular loading chamber, similar to that used in the Nautilus, to minimize reflections on the back of the dome. But here a newly stiffened bond connecting the voice coil and dome extends the high-frequency range to a rated 30kHz (–6dB).

The DM 602 S3, with its 7-inch driver, is rated down to 43Hz (–6dB)—a range well suited to trouble-free blending with a good subwoofer. B&W has used woven Kevlar as a cone material in its woofer/midrange drivers since the 1970s, with continual subsequent refinements. The Kevlar drivers used in the new models include a more open basket structure than in the Series 2 designs, and, like the tweeter, have upgraded bonding between the voice coil and cone.

One obvious feature of the woofer/midrange driver is the bullet-shaped device visible at the center of the cone. Such devices, known as phase plugs, are typically used to smooth a speaker's response. In most applications, they are attached directly to the pole piece, part of the stationary magnet structure of the driver, and do not move. The phase plugs in the DM 602 S3 and LCR 600 S3 are attached to (and move with) the cone itself, so they also double as dustcaps.

Crossover refinements in the Series 3 include newly selected capacitors chosen after extensive listening tests. Readers new to audiophilia may scoff at the notion that different brands and types of components that have identical specs—and even test the same using conventional measurements—can have different audible effects on the sound. Not everyone agrees with this—it's as controversial as audible differences among cables. But many of us at the Guide have heard such differences for ourselves, and more than one specialist audio manufacturer evaluates equivalently rated parts from different sources as part of its product-design listening tests.

The enclosure of the DM 602 S3 is heavily braced. As in the last version, it uses B&W's FlowPort, a dimpled, tapered port outlet said to minimize turbulence and the noise that can result from it. B&W also provides foam plugs that can be inserted in the port to damp its output. This changes the speaker's bass characteristics and may be desirable in some installations. The only way you'll know which works better in your system is to experiment. I found that my setup worked best without the plugs; the bulk of the auditioning (and all of the measuring) was done with open ports.

All of the technology described above is also found in the LCR 600 S3, a speaker very much a part of the DM 600 series despite the lack of "DM" in its model number. (B&W probably felt that a model called the "DM LCR 600 Series 3" would fail the dealer tongue-twister test.) This speaker can be used horizontally as a center-channel, as I did, or positioned vertically and used for other channels as well. The LCR 600 S3 has two woofers, which are slightly smaller than the one in the 602, and a 21/2-way crossover. Both woofers operate up to 300Hz, but one driver rolls off above that frequency, leaving the other one to handle the 300Hz–4kHz range.

The LCR 600 S3's port is at the rear, and the speaker is magnetically shielded. The DM 602 S3 is not shielded—presumably because the left and right speakers will be at least a few feet from any television susceptible to magnetic fields. (CRT-based sets are susceptible; those based on plasma, LCD, LCoS, and DLP are not.)

Both the DM 602 S3 and the LCR 600 S3 have two sets of terminals and can be biwired or biamped, as desired. I used single wiring for all of my listening.

The ASW 675 subwoofer has been designed specifically for the new DM600 line, although, like all subwoofers, it can be used with other speakers. Its 10-inch driver has a long-throw suspension and a composite cone of Kevlar, pulp, and aluminum, driven by a 500W, class-D amplifier with a switching-mode power supply. Controls include level and crossover-frequency knobs, a switch to defeat the internal crossover for use with pre-pros and A/V receivers that have their own bass management (i.e., most of them), an 80Hz highpass filter that will most likely be used in 2-channel systems that lack bass management, a signal-sensing auto-on option, a 0/180° phase switch, and a two-position equalization control selectable for maximum output or maximum bass extension.

Cosmetically, the entire line has been completely redesigned. I think it looks great—particularly in the Sorrento "light oak" finish, a high-quality vinyl veneer—but judge for yourself.

I used two rooms and two different systems for this review. I broke in the review samples in my smaller room, approximately 17 feet long by 13 feet wide with an 8.5-foot ceiling. The DM 602 S3s were all mounted on stands situated at the left and right in both the front and rear. The front stands were the B&W designs shown in the photos. The center was perched atop my 50-inch Hitachi rear-projection TV in the small room, and the subwoofer was parked in the left front corner of the room.

All grilles were removed for the auditions, and no damping plugs were placed in the speakers' ports. The front left and right speakers were toed-in toward my listening position in both rooms. All of my listening was done with the subwoofer engaged and the bass crossovers in the receiver (small room) and pre-pro (large room) set to 80Hz. The "A" (maximum extension) position of the subwoofer's equalization switch produced the deepest bass response, though the difference between "A" and "B" (maximum output) was insignificant on most program material.