Sonus Faber – Gravis B1 Subwoofer

Despite the audiophilic loathing of multi-channel and home cinema, the proliferation of small speakers in two-channel use indicates that subwoofers are godsends for those who cannot afford or house big speaker systems. Ironically, given that the Gravis B1 is Sonus Faber’s first subwoofer in nearly two decades, we should remember that the first product from the then-nascent brand in the early 1980s was the legendary Snail: a subwoofer with a pair of long wooden arms, at the ends of which were small satellite speakers. (Picture it, and you’ll get the snail imagery.) So anyone suggesting that the Italian brand is being opportunistic here, think again: when it comes to subwoofers, they are not arrivistes. Blessedly, the wait was worth it, for the B1 is a honey.

Additional Resources
• Read more subwoofer reviews from HomeTheaterReview.com.
• Explore speaker pairing options in our Floorstanding Speaker Review section.

Styled to match the Concerto family rather than its all-wood models, the Gravis boasts grained matte-black leather on every surface; I’d kill to have a flight bag in the same material. To dispel images of some S&M freak’s idea of a Fortnum & Mason hamper, the front and sides sport cloth grilles on bevelled frames, while the back contains the requisite controls. Additionally, the front and rear panels slope, and the edges are curved, so the B1 has an almost soft, organic look.

Why three grilles? Because the B1 houses a forward-firing 10in ‘active’ woofer with hard paper cone, augmented on both sides by ‘two passive radiators of the same diameter to obtain the most efficient and extended low frequency response.’ Again, lest its detractors wish to suggest that the company is venturing here onto new ground, Sonus Faber’s Extrema of a decade ago carried a passive radiator on its rear baffle.

Although the Italians state quite clearly that their first priority was performance worthy of critical two-way systems, the B1 is also magnetically-shielded for positioning near TV monitors; I’m willing to bet that 90 percent end up in home cinema installations. Inside the 14.5×16.5×16.5in (WxDxH), ‘decoupled construction for resonance control’ enclosure is a MOSFET based amplifier (300W peak) with 2-stage power supply. With the amp, three drivers and solid cabinetry adding up to a hefty 66lb, it feels as substantial as it looks.

Read more about the Gravis on Page 2.

On the back is a finned heat-sink and inputs for line level (RCA phono) and high-level (XLR), a rotary to set the switchable low-pass 24dB/octave filter – 38-65Hz through six positions – and a fixed high-pass filter operating above 20Hz. The amplifier possesses signal-dependent mute/start and soft start, and protection circuitry. A phase reversal switch is fitted, and there’s a gain control below the crossover rotary.

Let’s get my one complaint out of the way: the Gravis’s auto start-up is detectably slower than, say, the REL’s or the Spendor Sub 3’s. This was noticeable the instant I went into the Lexicon’s set-up program and there was an audible delay when it fed the B1 with the internal test signal; no other sub in my experience has exhibited this delay. This delay is sloppy, but not fatal. Conversely, how long the Sonus Faber takes to return to its dormant state after the absence of signal I haven’t been able to determine. Suffice it to say, when I immediately applied the test signals again, the Gravis responded immediately; 10 minutes later, it was also as per normal.

Giving it both 2- and 5.1 channel action, the B1 was used with the Lexicon MC-1 and five Martin-Logans (Script, Scenario and Theater) for A/V use, and in conjunction with both Sonus Faber’s own Concertinos and the Guarneri Homage, and assorted LS3/5As. With the DTS tracks of and , the Dolby Digital 5.1 , and both Dolby and DTS , the Gravis sailed through home cinema trials with authority and weight well in excess of what I expected from so compact a design. The Gravis made me think of big Italian singers, a real mortadella of a subwoofer, all lush and oozy and substantial. Real stick-to-your-ribs bass, capable of full-scale bellowing…forget the bombs and gunfire: listen to recordings of thunderous storms as in , or surround-sound audiences as per arena sequences. The Gravis conveys mass and power more than capable of overwhelming my 14x22ft room. And the Gravis possess attack on a par with the REL Strata III, previously my fave in this area.’s>

In spite of this basso profundo character, the Gravis can also show finesse – even more than the Spendor Sub 3. Think of it this way: you look at Pavarotti and you expect a voice like James Earl Jones; instead, you get a soprano who hovers. Although the Gravis never ventures onto soprano turf, it exhibits delicacy and detail and precision, even when wallowing strictly in bottom-octave territory. A/V didn’t demonstrate this, but a session with the Guarneris and Concertinos did. The Gravis added weight and scale without ever once imposing itself on the satellites, and it showed, with the Kodo drummer CDs, just how much bass notes – even solely percussive – vary in texture, tonal character and mass. In particular, I was smitten by the smoothness, even when I pushed the B1 to its limits: no lumps, no grating, just a velvety richness.

Without hesitation, I’m electing the Gravis B1 as my new reference subwoofer. It simplybetter than any other I’ve used. And there’s another reason why I’m giving it both thumbs up: through some out-of-character fluke on the part of an importer who speaks six languages but has never learned the word ‘bargain’ in any of them, this device has actually been priced sensibly. Like, uh, 999. And I had it pegged at 1495..