Recommended Components

A:

JL Audio CR-1: $3500
The CR-1 crossover has continuously variable high- and low-pass filters built around two banks of precision Linkwitz-Riley filters that can be set for 12 or 24dB/octave via. Front panel switch. Upon encountering the CR-1, LG "wondered where it had been all [his] life;" he's been using it ever since. "It's beautifully made, sonically transparent, performs a critical role in the optimal setup of subwoofrs, and has ergonomic bypass and mute functions that let you immediately hear the sonic iprovements of good bass management." (Vol.39 No.11 WWW)

JL Audio Fathom f110v2-GLOSS: $4000
This relatively small—16" × 13" × 17"—impeccably finished, powered, sealed-box subwoofer uses a 10" cone woofer and a 1.1kW class-D amplifier. The low-pass filter's turnover frequency can be set between 30Hz and 130Hz with 12dB or 24dB/octave slopes. There is no high-pass filter, but the latest, multiband version of JL's Digital Automatic Room Optimization (D.A.R.O.) processor is included (a microphone is supplied), which KR found impressively useful. Driving multiple JL subs from the LFE output of his multichannel server, KR perceived more solidity and definition in the pedal tones with an organ recording and an expanded dynamic scale. For listening in stereo, where an LFE output was not available, KR used JL Audio's CR-1 Active Subwoofer Crossover and decided that its bass management was subjectively more satisfying than simply having a subwoofer playing the LFE channel on multichannel music recordings. "The JL f110v2 is a mighty mite of a sub, conceding little to its larger brothers," he concluded. (Vol.43 No.8 WWW)

MartinLogan BalancedForce 212: $4,499.99/each
The two 12" aluminum-cone woofers of the 212 are mounted on opposite sides of their enclosure and operated in opposition to one another—an approach for which MartinLogan has coined the term BalancedForce. Power comes courtesy an internal pair of 850W class-D MOSFET amplifiers, themselves addressed with a choice of balanced and unbalanced connectors for left-channel, right-channel, and LFE (low-frequency effects) operation. Controls include continuously variable knobs for level, low-pass filter (30–80Hz), and phase (0–270°), plus an On/Off switch with a third choice for power-saving Auto mode, which detects an incoming signal and powers up the system accordingly. JI used two 140lb BalancedForce 212s with his own MartinLogan Prodigy loudspeakers, and was impressed with the results—especially with the newly remastered Led Zep catalog: "Kick drum and bass were tuneful and heavy … yet there was no sense of bloat or bass 'effect,' and the tonal balance from top to bottom just felt right and real." The only performance negative: the audible clacking of the system in Auto mode. Perfect Bass Kit costs $100. (Vol.37 No.10 WWW)

REL No.31: $7000
This massive, stackable, powered subwoofer uses a 12" driver with a carbon-fiber cone in a sealed enclosure, powered by a 900W class-D amplifier. It has both high-level and line-level inputs. Controls include crossover frequency and polarity switchable between 0° and 180°. RvB auditioned a pair of No.31s with his Focal Scala Utopia EVO speakers, with the crossover set to a low 29Hz. Although the full-range Focals extend to 27Hz, –6dB, RvB found that with the REL subwoofers the bottom note of a motif played on a synthesizer was not only louder; he felt it more, both physically and emotionally. "Its thrum was more fleshed out and menacing." Sonny Rollins's saxophone took on extra palpability with the RELs in the system: "I could better hear his breath pushing through the reed, preceding the brassy shimmer of each note as it left the bell." RvB had expected the two No.31s to bring increased force to the lowest reaches of his system's performance, and they did that, unflappably. "But the RELs also imbued the midrange with an extra dollop of clarity that you might not expect from what most of us regard as an LFE augmenter. In some music, they increased air," he concluded. (Vol.48 No.3 WWW)

SVS SB-3000: $1099.99 in Black Ash finish; $1199.99 in Piano Gloss Black finish
The new SB-3000 is 37lb lighter, a few cubic inches smaller, and $600 cheaper than the model it replaces in the SVS line—the SB13-Ultra—and while its built-in class-D amp is also slightly less powerful (800W vs 1000W), the new model is specified to reach even lower, extending to 18Hz instead of "just" 20Hz. The SB-3000's newly designed 13" driver sports an aluminum cone and boasts a new 2" split voice-coil. Wireless (Bluetooth) control of the subwoofer is made possible via SVS's smartphone app, which LG describes as "user-friendly"; wireless connection to one's music system requires the addition of the SVS SoundPath Wireless Audio Adapter Kit ($119.99). LG noted that the SB-3000 was "quicker to set up" than another recent sub and praised its bass performance for being "massive, powerful, and weighty" while preserving subtle details. His conclusion: "an outstanding choice for small to moderate-sized rooms." (Vol.42 No.9)

SVS SB16-Ultra: $2299.99
Just as a big dog needs a big leash, a big woofer cone needs a big voice-coil, if only to prevent the cone from flexing and the coil from shifting in its gap. So in designing their SB16-Ultra powered subwoofer, SVS equipped its 16" driver with an 8" edge-wound voice-coil—a coil so wide that it runs outside the driver's four big toroidal magnets. Indeed, SVS says that the SB16-Ultra's voice-coil is, to date, the largest used in a commercial subwoofer. (The driver as a whole weighs 63.9lb, almost precisely the average birth weight of a Holstein calf.) Joining all that bigness is a 1500W class-D amplifier, a computerized bass-management system that, like the SB16-Ultra's basic controls, is operated from a Bluetooth-friendly smartphone app, and an "uncluttered" rear panel that, according to reviewer LG, includes both unbalanced (RCA) and balanced (XLR) inputs and outputs. LG was also impressed by the 122lb SB16-Ultra's relative ease of installation, praising in particular its "smart" packaging, its four-page quick-start manual—and Merlin, SVS's online setup guide, which offers loudspeaker-specific recommendations for filter settings and the like. LG wrote that, after optimizing its setup, "it was clear that a single SB16-Ultra could produce more than enough bass extension and slam in my large listening room." (Vol.40 No.12 WWW)

Wilson Audio Specialties LōKē: $11,500 in standard finish
This powered subwoofer is intended to be paired with Wilson's smaller loudspeakers and other speakers of similar size. The 10" woofer is powered by a 500W Dayton Audio class-D amplifier. There are balanced and single-ended inputs and DSP settings include volume; high-pass, low-pass, and subsonic filters; a two-band parametric equalizer; and phase (0–180°). The LōKē comes with a standard power cable, spikes, Wilson's Acoustic Diodes, and various installation tools. JVS used a pair of LōKēs with his Wilson Alexia V loudspeakers, commenting that "you don't need golden ears to hear that low bass grows stronger and more focused when the LōKēs are engaged." But what did surprise him was that the LōKēs did more than reinforce the Alexia V's deep bass. As airy and 3D as an organ recital recorded in London's Royal Albert Hall sounded through the Alexia Vs by themselves, "the sense of a vast hall increased noticeably" with the LōKēs operating. "As the soundstage grew deeper, wider, and more coherent, as soundstage boundaries became more evident, as air between and around instruments and voices increased and the quality of music reproduction rose to mesmerizing levels, my appreciation for the transformative potential of the LōKē grew exponentially," he concluded. (Vol.46 No.11 WWW)

B:

Harbeth Nelson: $3190/pair
Standing 31" from the speaker platform on top to the tips of the cone-spiked feet on its base, the Nelson powered woofer / speaker stand uses the same Harbeth-made 5" drive unit as the HL-P3 minimonitor inside a grille cloth–covered, composite-material tube. A flat panel on the back of its round-caged bottom incorporates a receptacle for the wire-wart, 24V power supply for the built-in 50W class-D amplifier and a control knob adjusts the woofer's level. The crossover is set to 75Hz and, according to Harbeth, "the Nelson's digital signal processing unit optimizes the crossover frequency, phase, and shape so the Nelson takes over seamlessly as the host speaker's bass rolls off." HR used both Harbeth's P3ESR XDs and Falcon's Gold Badge LS3/5a's—see Loudspeakers—sitting on a pair of Nelsons and commented that the Nelsons "enabled both speakers to image from floor to ceiling and deliver a mesmerizing, precisely rendered spectacle that even LS3/5a purists like me could embrace." Harbeth's bass column "relaxed and clarified the P3 monitors in a manner that made all recordings easier to enjoy and scrutinize," he concluded, adding that the Nelson "adds bass weight in addition to some luxurious depth and atmosphere." (Vol.47 No.7 WWW)

JL Audio E-Sub e110: $2100 in Gloss, $1900 in Ash
One step down from JL Audio's Fathom series is the Florida company's E-Sub line, the entry-level model of which is the e110 in black ash finish. (Add $200 for gloss black.) The self-powered (specced at 1200W RMS) e110 sports a 10" driver and pairs of RCA inputs and outputs. With the sub's crossover engaged, the output jacks provide a 24dB/octave, Linkwitz-Riley–filtered high-pass signal; when the crossover is defeated, they provide a buffered version of the same signal that appears on the e110's input jacks. Controls include level, filter defeat, filter frequency, polarity, and variable phase; the e110's specified frequency response is 25116Hz, ±1.5dB (3dB at 23Hz). KR, who relied on Audyssey and Dirac Live software for EQ chores, found that, in his room, "useful response was maintained to below 15Hz. Pretty impressive for a pair of 10" drivers!" And although, as KR observed, "two 10" subs couldn't 'load' the room" as his larger subs did, the E-Subs offered "deep, powerful bass." (Vol.39 No.9 WWW)

KEF KC62: $1499.99
This minuscule—10" × 10" × 10"—powered subwoofer weighs 30.9lb and uses KEF's unique force-canceling, bipolar Uni-Core drive-unit, which has two opposed 6.5" diaphragms with concentrically sleeved voice-coils sharing a common magnetic pole-piece. The aluminum enclosure acts as the heatsink for the internal amplification and the KC62 includes line-level (RCA) and speaker-level inputs (Phoenix connector) and a variable (40Hz–120Hz) high-pass–filtered line-level (RCA) output. There are five DSP room-placement profiles: Room (for positioning away from walls); Wall (for next to a wall but not in a corner); Corner; Cabinet (near a corner, inside a cabinet); and Apartment (which reduces the level of the KC62's lowest frequencies). With Falcon's "Gold Badge" LS3/5as, HR noted that after some experimentation with settings and placement, as well as extending the minimonitors' low frequencies, the KC62 improved the speakers' midrange presence and spaciousness in ways that made it easier for him to look into the sound-space and stay focused on performances. "Instruments and voices sounded bigger, more physical, and easier to 'see' with the KC62 engaged." He also achieved excellent results with Magnepan .7s and KEF LS50s and concluded that the KC62 "took an already great speaker and made it greater. Isn't that what a subwoofer is supposed to do?" Class rating reflects limited output power. (Vol.44 No.6 WWW)

KEF KC92: $1999.99
This small, versatile powered subwoofer uses two drivers braced back-to-back, with a claimed response down to 11Hz and a maximum SPL of 110dB. This is achieved using the "Music Integrity Engine," a suite of custom DSP algorithms that include "Intelligent Bass Extension" (iBX) to monitor signal level and content to modulate output level and frequency response. KR tried a pair of KC92s with KEF LS60, KEF Blade Two Meta, and PS Audio aspen FR5 speakers, tweaking the settings using the KEF App, both by ear and by using a microphone and REW. (The KEF app asks if you are using one or two KC92s and, if using two, it lets you choose to use them either as a stereo pair or in mono by sending both channels of bass to both subwoofers. It then guides you through all the setup parameters, including the high-pass filter for the sub.) KR got superb, full-range in-room sound with all three types of speakers, writing that the KC92's construction, design, and feature set easily distinguish them from less expensive subwoofers, and he questioned whether pricier ones could offer higher performance given their size limitations. "The KEF KC92 is a sweet spot for subs." (Vol.48 No.1 WWW)

SVS 3000 Micro: $899.99
At 10.9" × 11.7" × 10.7" and weighing in at 26.7lb the 3000 Micro is similar in size and weight to the KEF KC62. It features two opposing 8" aluminum-cone drivers equipped with dual-ferrite magnets and powered by a 800W Sledge STA-800D2 class-D power amplifier. A Bluetooth smartphone app (Apple iOS and Android) and a control panel on the subwoofer's side plate both allow volume, low-pass frequency (30–200Hz), phase (in single-degree increments), polarity, room-gain compensation, and crossover slope (6, 12, 18, or 24dB/octave) to be adjusted. There is also a DSP-powered parametric equalizer, which allows users to create and save as many as three custom EQ settings. With the Falcon Gold Badge speakers, HR set the 3000 Micro's low-pass filter to 68Hz and the level to –29dB, at which point "bass-register piano notes snapped into full-textured focus. … [M]y system's octave-to-octave tonal balance seemed ideal. Bass and lower midrange exhibited a satisfyingly pure harmonic structure. Plus, all the bass sounds appeared to be coming from the LS3/5a's, not the sub." HR found that in his relatively small room, "the SVS's dual 8" cones projected their energy with more ease and flow than the 6.5" KEF KC62 cones had." However, he felt that more expensive KEF KC62s had better pitch definition, pace, and timing than the 3000 Micro. "The KEF's tone seemed slightly more correct, and it danced with slightly greater precision," he wrote, adding "but it was close." HR also had successes integrating the SVS subwoofer with Harbeth M30.2s and Magnepan .7s, concluding that "everything about my first SVS subwoofer experience pointed to a manufacturer that specializes in 'well and thoroughly conceived' subwoofer experiences." (Vol.44 No.8 WWW)