Subwoofer Reviews

The Quad ESL-989s sat 8' apart, 5' from the front wall, and 3' from the sidewalls, slightly toed-in toward my listening chair, and were driven by a Mark Levinson No.334 solid-state amplifier. The DD-18+ was driven from the auxiliary outputs of my Bryston BP-26 preamplifier via two 6m-long, balanced, line-level cables.

I loaded Velodyne's Digital Drive Plus Windows Interface Setup software on my laptop. I removed the DD-18+'s grille in order to connect the Velodyne's USB cable from the mini-USB port on the front of the sub to one of my laptop's USB ports. I then plugged the calibration mike into the jack on the DD-18+'s front panel, and placed the mike at ear height behind me, atop my overstuffed listening-room chair.

I briefly tested Velodyne's Self EQ software and confirmed that it worked (see Sidebar). However, I did the final subwoofer integration using the Auto EQ algorithm. This allowed me to watch the program mute the subwoofer, then test the frequency response of the Quads driven through the DD-18+'s high-pass filter (fig.1). Next, the Auto EQ routine made adjustments in eight subwoofer parameters (see sidebar) to generate a flatter room response (fig.2).

Once I was satisfied that my system's frequency response was as flat as possible from 15 to 200Hz, I stopped the CD playing the sweep tone and clicked the program's Save to DD+ button, to store my special EQ settings. The final settings were: Low-pass filter at 97Hz, high-pass filter at 80Hz (so I could play my Quad ESL-989 speakers at high volumes without tripping their protection circuits), rumble filter set to 15Hz; 24dB/octave; Phase "0"; Polarity inverted; and Volume set to "40."

Velodyne's Auto EQ room optimization and setup process is much easier to do than to describe. I depended on the clear writing found in the Velodyne manuals, which were helpful, detailed, and thorough, with good illustrations. Among automated EQ programs in aftermarket subwoofers, Velodyne's is one of the best I've used. However, I did find that if I disabled the high-pass filter, which means the Quads were run full-range, I was able to get a flatter response overall (fig.3).

Sound Quality
With the Quad ESL-989s driven by my Levinson No.334 amplifier but rolled-off below 80Hz, Mark Flynn's kick-drum opening to "Blizzard Limbs," from Attention Screen's Live at Merkin Hall (CD, Stereophile STPH018-2), delivered visceral bass punches without shutting down the speakers. The DD-18+ let me fully appreciate the pace, impact, and dynamics of percussion. Precise, tuneful, focused timpani whacks shook my listening room in the second section of Stravinsky's The Rite of Spring, with Esa-Pekka Salonen conducting the Los Angeles Philharmonic (SACD/CD, Deutsche Grammophon 00289 477 6198-2), and in the same passage with Eiji Oue conducting the Minnesota Orchestra (HRx 24/176 file from Reference RR-70). The DD-18+ fully reproduced the explosive rendition of Yoshihisa Taira's Hierophonie V by the Kroumata Percussion Ensemble (CD, BIS 232), which also demonstrated the Velodyne's ability to deliver compact, dense, fast timpani strokes. The DD-18+ delivered the full power of the furious, powerful bass-drum strokes that punctuate John Williams's Liberty Fanfare, from Winds of War and Peace, with Lowell Graham conducting the National Symphonic Winds (CD, Wilson Audiophile WCD-8823), which erupted as huge, gut-punching whacks.

The DD-18+ could move volumes of air to capture the inherent solidity and mass of a pipe organ's lowest pedal notes. This could create "room lock"; ie, a level of deep bass strong enough to be felt as a pressure wave. The sustained 32' note that concludes James Busby's performance of Herbert Howells's Master Tallis's Testament, from the Pipes Rhode Island collection (CD, Riago 101), initiated some powerful room lock: The air shuddered, causing the radiator panels to vibrate.

In fact, the DD-18+'s solidity, extension, excellent pitch definition, low coloration, and tonal correctness were perfect for pipe organ recordings. I clearly heard and felt the turbulent 25Hz pedal note that underpins Gnomus, from Jean Guillou's performance of his own transcription of Mussorgsky's Pictures at an Exhibition (CD, Dorian DOR-90117). The unusually wide dynamic range of the organ in the excerpt from Elgar's Dream of Gerontius on Stereophile's Test CD 2 (Stereophile STPH004-2), was most impressive—particularly the sustained final note, which produced room lock. The DD-18+ helped the Quads create a dense, texturally accurate sonic tapestry of full choir, harp, and organ-pedal notes in John Rutter's A Gaelic Prayer, with Timothy Seelig leading the Turtle Creek Chorale (CD, Reference RR-57CD). The Quad-Velodyne combo conveyed the massive, almost subsonic organ note that concludes Rutter's Lord, Make Me an Instrument of Thy Peace on the same disc—it was stunning in its power and pitch definition.

The DD-18+ also brought into sharp focus the bass timbres of other instruments, including that audiophile favorite, the double basses playing a sustained C, doubled by an organ pedal, in the opening of Richard Strauss's Also sprach Zarathustra, from Eric Kunzel and the Cincinnati Pops' Time Warp (CD, Telarc CD-80106). Tonally, the DD-18+ captured the tense energy and drive of Michael Arnopol's double-bass in the introduction to "Too Rich for My Blood," from Patricia Barber's Café Blue (CD, Premonition/Blue Note 5 21810 5). David Hudson's bass didgeridoo was reproduced with a power, speed, and dynamics I hadn't heard before in "Rainforest Wonder," from his Didgeridoo Spirit (CD, Indigenous Australia IA2003 D). The DD-18+ revealed the telltale sound of a fabric-covered mallet striking a big bass drum in H. Owen Reed's La Fiesta Mexicana, from Howard Dunn and the Dallas Wind Symphony's Fiesta! (CD, Reference RR-38CD), as well as Jerome Harris's careful bass work weaving in and out of "The Mooche," from his Rendezvous (CD, Stereophile STPH013-2).

The DD-18+ was especially magical when reproducing the emotion-generating power of the bass synthesizer, which makes that instrument so effective in movie soundtracks. Listen to its creepy, sinister effect in "Assault on Ryan's House," from James Horner's score for Patriot Games (CD, RCA 66051-2); the breathy synth-bass pulses that fill "Something's Wrong," from Randy Edelman's score for My Cousin Vinny (CD, Varèse Sarabande VSD-5364); the dark, slamming, repeated chord in "The Siege of Justiceville," from Alan Howarth and John Carpenter's soundtrack for They Live (CD, Enigma 7 73367-2); the dense, gut-tightening bass line in "Ain't Yo Bidness," from Insane Clown Posse's The Wraith: Shangri-La (CD, Psychopathic RIV 9912-2); the airy, ghost-like notes in "First Haunting/The Swordfight," from Horner's score for Casper (CD, MCA MCAD-11240); and the deep, sinister, thunderous synth notes depicting the footsteps of the beast in "The Carnotaur Attack," from James Newton Howard's music for Dinosaur (CD, Walt Disney 50086 06727).

Comparisons
I compared the Velodyne DD-18+ ($5799) with three other subwoofers: its predecessor, the DD-18 ($4799); the Bowers & Wilkins DB1 ($4500); and JL Audio's Fathom F113 ($4000). (The last two lack high-pass filtered outputs to drive the main speakers, so were used with Bryston's 10B line-level crossover.)

The DD-18+ bettered the DD-18 in raw power, transient articulation, pitch definition, and deep-bass extension. The non-automatic adjustment of virtual EQ sliders on a TV monitor now seems crude and primitive compared to the DD-18+'s completely automated, PC-based system.

The JL Audio Fathom f113, with its 13" cone, did quite well against the DD-18+. It was pitch perfect, and delivered dramatic dynamic contrasts. While it can optimize only one frequency band, the f113's optimization most closely matched the DD-18+'s non–display-based Self EQ mode. A single Fathom f113 didn't produce the room lock that the DD-18+ could, but two f-113s hooked up in stereo deepened and widened the soundstage more, and "disappeared" more convincingly, than any of the other subs.

The B&W DB1's PC-based setup software is closest to the DD-18+'s and is quite sophisticated, particularly because it can automatically adjust up to four bands between 20 and 200Hz, and its automatic optimization program and set-and-forget options (eg, gain, polarity, phase) can be run from the listening chair. Its graphic display offers good user interaction. The DB1's sound, too, was closest to the DD-18+'s, perhaps because the radiating area of its two 12" cones, one active and one passive, are close to that of a single 18" cone. It moved an impressive amount of air, was pitch perfect, and produced terrific room lock. Like the JL Audio Fathom f113, it lacks a high-pass filter, requiring an external crossover. However, its blend with the Quad ESL-989s wasn't as seamless as I achieved with the DD-18+.

Conclusions
The Velodyne DD-18+ is an outstanding subwoofer that produces massive but tuneful bass and some of the best pitch definition I've heard. Add to that its fine cabinetry, and the ease and convenience of running Velodyne's software and setup from my listening chair, and the DD-18+ excelled. Despite the daunting number of features, controls, and user-adjustable options offered, when I'd installed the setup software on my laptop, things went more quickly and smoothly than I had expected.

The DD-18+ played the deepest bass passages with minimal distortion, producing massive bass output with low coloration. Additionally, the DD-18+ sounded involving and musical, with articulation of bass instruments that was second to none. These strengths allow me to rank the Velodyne DD-18+ with the very best aftermarket subwoofers. It gets my nomination for a solid Class A rating in this magazine's "Recommended Components."