Although many high-end audio products are described as revolutionary and as breakthroughs in design when new, most audiophile components now on the market have not changed our way of relating

to such products in the way the iPad has done. Once in a while, a new audio product does move in that direction by enabling the audiophile to do install a product and optimize its performance in a different way.

The last applies to the Bowers &Wilkins Group’s new DB1 subwoofer: In addition to its automated room-compensation system, which samples over a wider bandwidth and adjusts for more room modes than does that of the competition, the DB1’s menu-driven controls can be conveniently adjusted from a laptop computer rather than the user having to stretch to reach them on the sub’s front panel.

ExternalsLike most subwoofers these days, the DB1 has its own amplifier, uses equalization to generate powerful deep bass output from a small enclosure, and contains a self-optimizing setup program. This approach has proven more popular with buyers than subs that rely on a large enclosure to generate deep bass.

larry greenhill

Bowers & Wilkins DB1subwoofer

Description Powered subwoofer in sealed enclosure. Drive-units: two 12" long-throw Rohacell-cone woofers, each with 3.66" voice-coil and 11-lb magnet. Frequency response: 17–145Hz, +-±3dB. Passband of automatic room compensation: not stated. Low-pass filter: 40–120Hz (adjustable), slope, phase. High-pass filter: no option. Total harmonic distortion: not specified. Amplifier: 1000W RMS. Rated power consumption: 300W. Input impedance: 15k ohms. Signal/noise ratio: >100dB.

Inputs per channel: stereo unbalanced (RCA); mono LFE, unbalanced (RCA); and mono balanced (XLR). Controls: 5 presets, input sensitivity, gain, graphic equalization, low-pass frequency, slope, phase, room compensation, auto on/standby, trigger on/standby, trigger preset switching, RS-232 automation control. Included: detachable IEC power cord; 4 spiked feet, 4 rubber feet; owner’s manual; USB-connected soundcard to be inserted in first USB port in owner’s computer; interconnect cable from

second USB port in owner’s computer to DB1 input panel (serial RS232 connector); calibration microphone (XLR jack); cable from microphone (XLR) to soundcard (minijack); line-level interconnect from soundcard output (minijack) to DB1 input panel (RCA).Dimensions 19.3" (490mm) H by 18.1" (460mm) W by 16.2" (410) D. Weight: 97 lbs (44kg).Finishes Piano Black Gloss, Cherrywood, Rosenut.Serial Number of Unit Reviewed 0000635. System v.1.0.0.0.0, DSP v.1.0.0.435.

Price $4500. Approximate number of dealers: 250. Warranties, parts & labor: 5 years drive-units, 2 years electronics.Manufacturer Bowers & Wilkins Group, Ltd., Dale Road, Worthing, West Sussex BN11 2BH, England, UK. Tel: (44) 01903-221500, Fax: (44) 01903-221501. Web: www.bowers-wilkins.co.uk. US distributor: B&W Group North America, 54 Concord Street, North Reading, MA 01864-2699. Tel: (978) 664-2870. Fax: (978) 664-4109. www.bowers-wilkins.com.

specifications

ELECTRONICALLY REPRINTED FROM FEBRUARY 2012

Bowers & wilkins DB1 suBwoofer

left and right control buttons can be used to toggle between different presets, while the up and down buttons control the subwoofer’s output gain. Pressing and holding the central button brings up the DB1’s setup mode. The left- and right-arrow buttons bring up various menu screens, while the up and down buttons select items within a menu, and the cen-ter button saves selections and moves on to the next menu. Selecting Audio from the Setup menu brings up a menu of adjustable output features, including choice of preset, low-pass filter settings (slope and turnover frequency), the input sensitivity level (a red LED flashes if you overload the input), gain, normal or inverted polarity, and phase. There is a separate menu for a five-band equalizer (20, 28, 40, 56, and 80Hz), each band adjustable from +5 to –10dB. With all the levels of the DB1 set to their default value of 0dB,

Measuring about a foot and a half wide and tall and 16" deep, the DB1 has two opposed, 12" drive-units. On the rear panel beneath the styling groove that runs all the way round the enclo-sure’s base are the input connectors: mono RCA for low-frequency effects (LFE) from a home-theater proces-sor; stereo unbalanced RCA from a stereo preamplifier’s auxiliary main outputs; mono XLR; minijacks for a trigger on/off signal and for the room-compensation test signals from the system’s soundcard; a DB-9 serial input to receive control signals via RS232 from the owner’s PC (sorry, Mac users); and an IEC inlet for the detachable

power cord.Beneath the groove on

the DB1’s front are the large on/off switch (with power-on LED) and the controls, grouped in a diamond pattern of five pushbuttons (up, down, left, right, and

Set-Up), for navigating the various menu screens that come up on the extremely bright but tiny (1" square) organic LED display next to them. When the DB1 is first turned on, the

The DB1 uses two 12" drive-units, powered by a 1000w amplifier.

Testing subwoofers is not as lonely a business as I had thought. One Stereophile reader, Darren Gum, wrote to criticize my use in

reviews of extra hardware to achieve more transportable subwoofer setups; eg, the virtual spectrum analyzer in my Velodyne DD-18 subwoofer, and Bryston’s 10B-SUB outboard electronic crossover ($2395; reviewed in May 1994 and November 2005), which I used with subwoofers that didn’t have high-pass feeds for the satellite speakers. Gum worried that most audio-philes wouldn’t have access to the extra gear, and that different results might have occurred had I used only my ears.

His argument made sense. Most read-ers set up their subwoofers by ear, unless the dealer comes by to “tune” the system.

Using my ears to set a subwoofer’s polar-ity, match its output to that of the Quads, and set its low-pass filter’s frequency would either work as well as my extra gear or not. I decided to try it both ways: I first set up the B&W DB1 using only my ears, then set it up again using my measuring gear.

Before setting up the DB1, I measured the Quads’ room response using the signal generator and spectrum analyzer built into the Velodyne DD-18 subwoofer (reviewed in June 2004, www.stereophile.com/subwoofers/604velodyne/index.html) that sits at the center of my room’s front wall. Clearly, using Velodyne’s elec-tronics was not part of the B&W’s setup instructions, but had proven helpful in setting up other subs.

After setting the DD-18’s volume con-trol to “0” so that its 18" drive-unit would remain silent while I took measurements of the B&W, I rested the Velodyne calibra-tion mike on the back of my listening chair, at my seated ear height of 37" above the floor and triggered a repeated 20–200Hz sweep tone that I fed into the Auxiliary in-put of my Bryston BP-26 preamplifier. The Velodyne’s sweep signal revealed that the Quads’ output was relatively flat down to 80Hz, then fell 10dB by 35Hz (fig.1). I then measured the DB1’s uncorrected in-room response, which revealed strong output from 20 to 100Hz, with prominent room modes evident at 45 and 65Hz (fig.2).

Following the online instructions, I set up B&W’s Room Acoustics Compensation program by plugging the DB1’s soundcard

B&W Room acoustics compensation

Fig.1 Quad esl-989, in-room response, 20–200Hz, no subwoofer (25dB vertical range).

Fig.2 B&w DB1, in-room response, 20–200Hz, room Acoustics Compensation off, (25dB vertical range). note peaks at 45 and 65Hz.

Fig.3 B&w DB1, in-room response, 20–200Hz, room Acoustics Compensation on (25dB vertical range). note that peaks at 45 and 65Hz are lower in level.

I controlled the DB1 with B&W’s SubApp program.

Bowers & wilkins DB1 suBwoofer

Room Acoustics Compensation, continued

available on the control panel: naming the presets, and launch-ing the DB1’s Room Acoustics Compensation routine. The tools needed to run that last item—a calibration microphone, four connector cables, and a USB-connected soundcard that generates the necessary test signals—are included with the subwoofer. With SubApp, the DB1 can take measurements of the room, then adjust its internal equalizer to compensate for up to four room-mode peaks within its operating range.

InternalsThe DB1’s construction, fully described in a white paper posted at www.bwgroup-support.com/reference.html, includes: two mechanically opposed 12" woofers separated by a par-tially open internal partition; 1"-thick walls of MDF with 3⁄4"-thick bracing panels to minimize vibration; digital sig-nal processing (DSP) circuits to run the menu-based control system rather than physical switches; home automation capability; and the 1000W switching amplifier, equalized to produce linear output. Like the JL Audio Fathom f212, the DB1 lacks a high-pass filter to shape the bass response of the main speakers, it being assumed that this will be taken care of by the preamplifier/processor or A/V receiver’s bass management function.

the subwoofer has the THX standard sensitivity of 109dB spl at 1m for an input of 1V RMS.

Because I found its display panel difficult to see from my listening chair—my right-channel Quad ESL-989 speaker blocked my view—I controlled the DB1 with B&W’s Sub-App program, which is compatible with Windows XP, as well as Vista and Windows 7 (both 32- and 64-bit versions). Not shipped with the subwoofer, it must be downloaded from www.bwgroup-support.com. SubApp provides graphi-cal user interface controls for the DB1’s gain, phase, polarity, and equalization, and enables two additional functions not

into a USB port on my Windows laptop; connecting one cable to the soundcard’s minijack connectors to send its test signals to the sub, and another to receive the feed from the calibration mike; and plugging a third, long USB-to-RS232 cable from a sec-ond USB port on my laptop into the RS232 connector on the DB1’s service panel.

That done, I ran B&W’s SubApp Windows program. When I first clicked the onscreen Run button, the DB1 played some rapidly stepped test tones, then stopped and indicated that the volume level was too low for it to take a measurement. I checked and found a loose connection in a cable plugged into the soundcard output. I fixed it, then successfully reran the compensation routine, which involved the App taking eight different measurements, without the Quads connected (fig.3).

To set up by ear, I turned the Quads back on and matched the DB1’s volume, phase, and polarity settings, ran the Room Acoustics Compensation, and listened for the tightest bass. I left the DB1’s low-pass filter at its default setting of 80Hz, and selected a low-pass filter slope of 24dB/octave. I saved these settings as Preset 1. To my surprise, the Velodyne’s spectrum

analyzer showed a surprisingly flat in-room response (fig.4). The sound was spec-tacular, especially playing organist James Busby’s recording of Herbert Howells’ Master Tallis’s Testament, from Pipes Rhode Island (CD, Riago 101, no longer available). I was delighted to hear extraordinarily tight, clear, sustained organ-pedal notes reproduced with good pitch definition and solidity, and with enough power to shake loose objects in my listening room.

To set up by gear, I returned the DB1 to its factory default settings—no room compensation—by selecting a new Preset to clear out the previous Room Acoustics Compensation settings. I ran SubApp a second time, and used my laptop’s keyboard to adjust the virtual gain sliders

in SubApp to match the outputs of the DB1 and the Quads while watching the resulting room-response curve on the TV monitor. I then adjusted the DB1’s low-pass filter frequency to achieve the flattest line on the sweep signal display. The display showed that a low-pass frequency of 70Hz—not the 80Hz I’d used before—and a low-pass filter slope of 24dB/octave gave the flat-test line representing the room response. Finally, I found that setting the DB1’s phase to 90° gave the flattest response on the TV monitor, not the default 0° setting I’d used before (fig.5). I loaded the new settings into Preset 2,” then again played Master Tallis’s Testament. I heard the same clean, deep bass, and this time it was even more focused and solid.—Larry Greenhill

Fig.5 Quad esl-989, in-room response, 20–200Hz, with B&w DB1 subwoofer, room Acoustics Compen-sation on, set up by Velodyne measurement, in-room response (25dB vertical range).

Fig.4 Quad esl-989, in-room response, 20–200Hz, with B&w DB1 subwoofer set up by ear (25dB vertical range).

A highly flexible cable is used to prevent “tinsel

fractures” from developing

in the DB1’s internal wiring

from the drivers’ constant motion.

inside, the DB1 features B&w’s “Matrix” construction.

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Bowers & wilkins DB1 suBwoofer

processors to optimize the sub’s frequency response in the listener’s room by adjusting its output to compensate for a single peak room mode. However, only the B&W DB1 lets its owner run its automatic optimization program and adjust its set-and-forget controls (eg, gain, polarity, phase) from the listening chair—though it’s necessary to connect a PC to the subwoofer with the long line-level cables (supplied).

The DB1’s Room Acoustics Compensation program probes the listening room with a tone sent to the sub’s input, then samples its audio output in the room with eight closely bunched measurements taken by the supplied mike. After analyzing the results, it applies four-band equalization to correct the four most prominent resonance room peaks in the sub’s range by reducing its output in a narrow band around each peak. The procedure gathers information over a passband of 30–140Hz, and gathers additional information below 30Hz. However, the DB1’s ability to adjust for more than one peak is inversely related to the size of the area in which measurements have been taken. The smaller the area, the greater number of peaks—up to four—for which the program can compensate. If the owner takes measurements over an area wide enough to include several listeners, the program will adjust for only the most prominent room mode.

SetupI unpacked the DB1 and moved it into the right corner of my living room, behind one of my Quad ESL-989 speakers, positioned so its control panel and display faced out into the room, and each of its two drivers faced one sidewall. The Quads sat 8' apart, 5' from the front wall and 3' from the sidewalls, slightly toed-in to my listening chair and driven by a Mark Levinson No.334 dual-mono solid-state amplifier. My chair was 10' from each Quad. The DB1 was connected to the outputs of my Bryston BP-26 preamplifier via two 6m, unbalanced, line-level interconnects.

The B&W DB1 has one of the easiest and quickest setup routines I’ve encountered with a subwoofer of this sophisti-cation. Setup took less than 10 minutes, whether by ear or by gear. (See Sidebar, “B&W Room Acoustics Compensation”).

SoundKeeping true to Darren Gum’s request in the sidebar, I evalu-ated the sound of the DB1 without the help of the Bryston 10B-SUB’s high-pass filter to restrict demands on the Quads to play very low bass. This helped maintain the Quads’ upper-midrange and treble transparency, but caused their protection circuits to kick in during loud bass peaks. For example, both Quads shut off at the beginning of Mark Flynn’s kick-drum introduction to “Blizzard Limbs,” from Attention Screen’s Live at Merkin Hall (CD, Stereophile STPH018-2). However, I liked the Quads’ unfiltered, full-range sound so much that I dialed back the preamplifier’s volume to avoid triggering further shutdowns.

From the start, I enjoyed the DB1’s ability to move air, its superb pitch definition, and its ability to integrate its own deep bass with the Quads’ midbass. I was most impressed

B&W stuffed two 12" drivers into the smallest enclosure possible and reduced the resistance of the drivers’ spiders and dampers at the extremes of the cones’ 1.6" range of travel by using a pliable progressive-roll spider, a voice-coil of rela-tively small diameter (75mm). The woofer cones are made stiff by using a composite of carbon-fiber skins over a core of Rohacell. A highly flexible cable is used to prevent “tinsel fractures” from developing in the DB1’s internal wiring from the drivers’ constant motion.

The DB1’s internal electronics include a signal input circuit board that connects the analog input to digital, a mother-board, a DSP board, the amplifier and its power supply, and an auxiliary power supply to run the digital circuits when the sub is in standby mode. The DSP functions are handled by an Analog Devices Sigma chip; this equalizes the subwoofer, provides low-pass filtering and phase control, adds a five-band graphic equalizer, runs the room-compensation software, and generates an “impact overlay” preset to enhance home-theater sound effects. The DB1 can store five user presets.

Automatic Room Acoustics CompensationOther subwoofers I have reviewed—including the Velodyne DD-18, REL Studio III (October 2004, www.stereophile.com/subwoofers/1004rel/index.html), and Revel Ultima SUB-30 (November 2004, www.stereophile.com/subwoofers/1104revel/index.html)—have provided test tones and equalizer controls, but require the owner to interpret the findings and make the appropriate adjustments. More recently, JL Audio’s Fathom f113 (September 2007, www.stereophile.com/subwoofers/907jl/index.html and Fathom f212 subs (April 2010, www.stereophile.com/subwoofers/jl_audio_fathom_f212_powered_subwoofer/index.html) are shipped with a self-adjusting firmware routine that uses calibration microphones and internal signal generators and

The B&W DB1 has one of the

easiest and quickest setup

routines I’ve encountered

with a subwoofer

of this sophistication.

The front panel features a small but very bright organic-leD display.

Bowers & wilkins DB1 suBwoofer

ComparisonsListening also to the Velodyne DD-18 ($4999) and JL Audio Fathom f113 ($3600) subwoofers allowed me to better grasp the characteristics of the B&W DB1 ($4500). The similarly priced DD-18 has a high-pass filter and a larger driver (18"), and uses servo correction; its audible bass power seemed on a par with the DB1’s. The DB1 and Velodyne produced the most room lock. The less-expensive JLA Fathom f113 had slightly better pitch definition. I heard a deeper, wider soundstage when I had two f113 subwoofers playing in stereo, compared with the single DB1, but I didn’t have two identical pairs of DB1s or Velodynes to determine if either could do as well. Even with these differences, however, I could easily live with any of these subwoofers.

ConclusionsThe B&W DB1 proved to be a real pocket rocket, produc-ing from a relatively small enclosure taut, powerful deep bass with outstanding pitch definition. Add to that its fine cabine-try and the ease and convenience of running B&W’s Room Acoustics Compensation software and setup adjustments from my listening chair, and the DB1 really excelled.

As a two-channel guy, I would have preferred that B&W included a switchable high-pass filter for managing the bass, so that I could obtain that extra bit of dynamic range from my Quads without clipping, but the combination of DB1 and ESL-989s sounded so good that it more than offset my frustration with having to keep the volume lower. However, DB1’s ability to blend sonically with my Quad electrostatics, more than justifies its high asking price. And the ability to fine-tune its performance from the listening chair is a truly in-novative step in making subwoofer setup easier, more feasible, and ultimately more reliable. These strengths put the DB1 on my short list of recommended subwoofers. n

with the DB1’s power while producing clean, tuneful low frequencies. The fortissimo bass-drum strokes in the second movement of Stravinsky’s The Rite of Spring, with Esa-Pekka Salonen conducting the Los Angeles Philharmonic (SACD/CD, Deutsche Grammophon 00289 477 6198-2), seemed to jump out into the room with tremendous speed and impact. I heard the same punch from the bass percussion in another performance of Rite, by the Minnesota Orchestra under Eiji Oue (HDx DVD-R, 24-bit/176kHz, Reference RR-70). The DB1 captured the distorted, menacing bass synth that opens “Deeper Wells,” from Emmylou Harris’s Spyboy (Eminent EM-25001-2), as well as the stark impacts of the explosive timpani strokes in Yoshihisa Taira’s Hierophonie V, performed by the Kroumata Percussion Ensemble (CD, BIS BIS-232).

The DB1’s tuneful bass power allowed it to not only re-produce the bass notes of pipe organs, but also to reliably cre-ate room lock: when an organ note massively vibrates the air in my listening room without boom. This clean depiction of deep bass power was apparent at even lower volumes, such as the soft but stunning deep pedal note that ends the excerpt from John Atkinson’s recording of Elgar’s Dream of Gerontius on Stereophile’s Test CD 2 (CD, Stereophile STPH004). The massive, almost infrasonic organ note that ends Timothy Seelig and the Turtle Creek Chorale’s performance of “Lord, Make Me an Instrument of Thy Peace,” from John Rutter’s Requiem (CD, Reference RR-57CD), was stunning in its power and beauty. The DB1 helped the Quads create a deep, broad soundstage on which deep pedal notes, full choir, and harp surged out from Rutter’s A Gaelic Prayer, on the same disc, and delivered the rumbling pulses that underpin Gnomus, from Jean Guillou’s performance of his transcription of Mussorgsky’s Pictures at an Exhibition (CD, Dorian DOR-

90117). Mary Preston’s raucous interpretation of the Toccata of Widor’s Organ Symphony 5, on Organ Odyssey (CD, Refer-ence RR-113CD), was equally dramatic with the DB1.

The DB1 also revealed the characteristic bass timbres of other instruments, such as: the taut, dense energy of Michael Arnopol’s double-bass in the in-troduction to “Too Rich for My Blood,” from Patricia Barber’s Café Blue (CD, Premonition/Blue Note 5 21810 2); the harsh shudder of David Hudson’s bass didgeridoo, which drives “Rainforest Wonder” on his Didgeridoo Spirit (CD, Indigenous Australia IA2003 D); the distinct tonal steps of Glen Moore’s plucked double-bass notes in

“The Silence of a Candle,” from Oregon’s Beyond Words (CD, Chesky JD130); the delicate bass-guitar line that Jerome Harris threads among the other instruments in “The Mooche,” from the Jerome Harris Quintet’s Rendezvous (CD, Stereophile SPTH013-2); the double-basses playing the sustained low G in the introduction to Richard Strauss’s Also sprach Zarathustra, from Erich Kunzel and the Cincinnati Pops’ Time Warp (CD, Telarc CD-80106); and the fabric-covered mallet used on the bass drum in H. Owen Reed’s La Fiesta Mexicana, from Fiesta! (CD, Reference RR-38CD).

Analog Sources Linn Sondek-Lingo turntable with Lingo power supply, Ittok tonearm; Spectral cartridge; Day-Sequerra FM Reference Signature tuner.Digital Sources Bryston BCD-1 CD player, Bryston BDP-1 digital transport with USB-2 flash drives and external USB hard drive, Bryston BDA-1 D/A converter, NetGear WN-350 wireless router connected to BDP-1 via Ethernet.Preamplifier Bryston BP-26.Power Amplifiers Mark Levinson ML-2 monoblocks, No.334, No.27.5, No.532H.Loudspeakers Quad ESL-989; Velodyne DD-18, JL Audio Fathom f113 subwoofers.Cables Digital: Bryston, Hosa AES/EBU; Wireworld Starlight Coaxial S/PDIF. Interconnect: Mark Levinson Silver, Red Rose Silver One, Totem Acoustic Sinew single-ended, Pure Silver, Bryston balanced. Speaker: QED X-TUBE 400, Pure Silver R50 biwire double ribbon, Ultralink Excelsior 6N OFHC, Coincident Speaker Technology CST 1.Accessories Bryston Universal Silver BR-2 remote control, Torus RM-20 Power Isolation Unit, ATI SLM-100 analog sound-level meter. Listening room: 26' L by 13' W with 12' H semi-cathedral ceiling, moderately furnished with sound-absorbing furniture. Left wall has large bay window covered by Hunter Douglas Duette Honeycomb fabric shades. Rear of room opens through 8' by 4' doorway into 25' by 15' kitchen.—Larry Greenhill

associated equipment

The B&W DB1 proved to be a real pocket rocket, producing from a relatively small enclosure taut, powerful deep bass with outstanding pitch definition.

Posted with permission from the February 2012 issue of Stereophile ® www.stereophile.com. Copyright 2012 Source Interlink Media. All rights reserved.For more information about the use of this content, contact Wright’s Media at 877-652-5295

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