Sonus faber Gravis VI Subwoofer Reviewed

Published On: September 9, 2019
Last Updated on: October 31, 2020
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Sonus faber Gravis VI Subwoofer Reviewed

Dennis says that Sonus faber's Gravis VI subwoofer is the single most gorgeous audio component to ever cross his threshold. But does its unusual design deliver the goods in terms of performance?

Sonus faber Gravis VI Subwoofer Reviewed

  • Dennis Burger is a native Alabamian whose passion for AV began sometime before the age of seven, when he dismantled his parents' brand new 25-inch solid-state Zenith console TV and exclaimed--to the amusement of no one except the delivery guy--that it was missing all of its vacuum tubes. He has since contributed to Home Theater Magazine, Wirecutter, Cineluxe, Electronic House, and more. His specialties include high-end audio, home theater receivers, advanced home automation, and video codecs.

Sonus faber's Gravis VI subwoofer is simply the most gorgeous piece of AV gear to ever cross my threshold. That's an odd statement to make about a sub, to be sure, and certainly an odd way to begin any review. But there's simply no denying that its design is the first thing you notice about the Gravis VI. It's probably the second, third, and fourth thing you notice, as well.

Sonus-faber_Gravis_VI_front.jpgOnce you get used to the leather-wrapped chassis, hand-finished wood topper, and taught-string grille, though, there are still elements of the Gravis VI's design to be ogled at. Because in addition to being a gorgeous piece of kit, it's also a decidedly unusual one from a design point of view. The Gravis VI is a sealed, dual-active-driver design, with a pair of trilaminated "ParaNanoCarbon" 12-inch cones driven by an 1,800-watt Class AB amp. Rather than mounting its drivers in opposition, though, Sonus faber cooked up a configuration that involves one front-mounted driver, and one bottom-mounted driver whose magnet, voice coil, and spider actually hang out of the cabinet, with the magnet sinking into a hole in the plinth, above which the main cabinet sits.

Whatever your initial thoughts about such a configuration, it results in, or at least contributes to, a subwoofer with impressive specs, including a -6dB point of 18Hz and a -3dB point in the neighborhood of 20Hz. That's certainly nothing to sneeze at from a cabinet of this size, which while not exactly falling into the "compact" category, certainly doesn't eat up as much space as many other high-performance subs. All in all, the Gravis VI measures in at 24.2 inches high by 17.6 inches wide and 23 inches deep. That's almost as tall as the Paradigm Defiance X15 I recently reviewed, though the Sonus faber simply doesn't feel anywhere near as big, perhaps due to its floating design, and perhaps due to its significantly slimmer front profile.


At any rate, the Gravis VI is designed for very different rooms--and very different systems--than the X15. Engineered and outfitted to be a good match for Sonus faber's own Homage Tradition and Reference speaker collections, prices for which run upwards of $130,000, the Gravis VI carries a premium price tag of €6,000 in the EU and $7,000 in the US, putting it more on equal footing with JL Audio's f212v2 in terms of price. But if aesthetic refinement is near the top of your priorities list for a new sub, I daresay the Gravis VI, with its luxurious Italian styling, is playing around in territory wholly its own, at least in terms of subwoofers.

The Hookup
With a fighting weight just shy of 115 pounds, the Gravis VI isn't one you'll be unboxing and positioning by your lonesome, most likely, but Sonus faber has packaged the sub such that it's not a bear to get out of the box, nor the foam inserts between said box and subwoofer. The cabinet itself comes in a sturdy bag, rather than the flimsy plastic or cloth found wrapping most subs, and the instructions (flip upside down, open, flip again, lift box, voilà) are clear and easy to follow. Atop the sub (actually, at the bottom of the box once you've flipped the box over and back again) you'll find a five-foot power cable, a cleaning kit comprised of Cristalux spray and a microfiber cloth, and the grille for the Gravis VI. The latter comes out of the box looking like a pile of black spaghetti tangled up around a pair of chopsticks, but a few minutes of detangling and some tension applied during the installation process will straighten out those strings lickety-split, and affixing the two support rods to the sub itself isn't all that difficult.

Sonus-faber_Gravis_VI_rear.jpgIn addition to its pair of unbalanced RCA and pair of balanced XLR stereo/LFE inputs, the Gravis VI also features a high-level Speakon connector, which is a bit of an unusual sight on this side of the pond, at least in consumer electronics.

The sub also features a Bluetooth 4.0 LE antenna for connecting the Gravis Sub Control app for iOS and Android devices. The app not only gives you access to the Gravis VI's four EQ presets--Audiophile, Cinema, Night, and Streaming--but it's also where you'll find crossover settings (variable between 40 and 150Hz), phase control (0 to 360 degrees), parametric EQ (eight filters), delay, and the automatic room calibration feature. The latter works by having you hold your mobile device close to the sub itself while test tones play, then move back to your listening position for another series of tones. It's quick, it's simple, it's easy, and it actually does a good-enough job of ameliorating standing wave issues that you may find you don't need to employ room correction on your preamp or receiver, depending on the material makeup of your room. It's also, of course, handy for 2.1 systems, many of which lack room correction or PEQ altogether.

Electronics in this system were a little varied, although my Roku Ultra and Oppo UDP-205 were common sources. For preamps, I did quite a bit of swapping out between my Marantz AV8805 and Emotiva XMC-1 preamps, with Emotiva's new RMC-1 thrown in the mix for a bit, mostly toward the end of my evaluation.

One thing that does bear mentioning regarding setup of the Gravis VI: while assembly and app-based tuning and tweaking of its various features are all quite straightforward and intuitive, placement of the sub within the room may require a bit more experimentation than you're accustomed to. Sonus faber seems, as indicated by the manual for the Gravis VI, to favor side-wall positioning, which frankly has never worked as well for me in this room with other subs. When I relented, rearranged some decorations, and opted for placement more in line with what Sonus faber suggests, though, I found a sound that I couldn't quite eke out of the sub by fiddling with placement more in line with the norm for this room: utter control and authority, matched by impeccable musicality and satisfying output.

Once I arrived at the optimal, though unusual, position for the sub, after a good bit of moving and no small amount of salty language, I sat down for some serious listening. Given the emphasis that Sonus faber places on musical reproduction across its entire lineup, this is where I turned my attention first. I'll admit, though, that I didn't begin with any carefully considered bass stress tests. For quite a few listening sessions, I simply sat down with a glass of Warre's Late Bottled Vintage Port and just sort of let the music follow wherever my mood took me.


It didn't take long for me to be duly impressed. Five tracks into Ray Charles' duet/cover album Genius Loves Company (CD, Concord Records), Brother Ray's duet with Natalie Cole, "Fever," leapt out into the room and hypnotized me like that freaky snake thing in The Jungle Book. Granted, the bass in this track isn't particularly deep, nor is it very hard-hitting. But that all-too-familiar bassline does dance around quite a bit between 40something Hz and somewhere in the neighborhood of 70something, the latter being within range of the crossover point I set between the Gravis VI and my GoldenEar Triton One.R towers for the bulk of this review. And while not the loudest part of the mix, that being the vocals, the bassline is generally the loudest element of the instrumentation by three-to-six decibels. In other words, while not exactly your typical butt-shaker demo, "Fever" gives the Gravis VI plenty to do: namely, drive the song forward.

What struck me in particular about its performance was how even-keeled it was. Those two bouncing notes that dominate the bassline were, perceptually at least, absolutely on equal footing throughout, despite the near-octave between them. There was also an undeniable effortlessness to the delivery of the bass, as well as a palpable authenticity to both the attack and decay.

Ray Charles: Fever (with Natalie Cole)

Continuing my random stumble through my music library, not really searching in particular for good bass demos but simply enjoying the music, I happened upon another unlikely spotlight for the Gravis VI's capabilities: "Heirloom," from the DualDisc release of Björk's Vespertine (Elektra). If you've only ever listened to this track on two-channel systems sans sub, you may not have noticed that it's propelled by a series of sinewave bass notes that flitter around between just north of 40 and just north of 70 Hz, not wholly dissimilar in frequency to the Ray Charles track, but with an entirely different tempo, texture, and timbre given the electronic nature of Björk's music.

Again, the consistency of loudness between those notes struck me immediately. But what makes "Heirloom" a very different, and arguably more difficult subwoofer test is the unrelenting sustain of each note. There's no real attack or decay to speak of here, but the droning nature of the bassline does present plenty of opportunity for more audible distortion to rear its head. And I never heard such, which speaks, in my opinion, to a very well-designed DSP, not to mention a well-engineered cabinet and driver array.

Björk - Heirloom - Music Video

Frankly, the Gravis VI's performance with music held me under such sway that when it was time to switch to movies, I couldn't resist the urge to pop in something with a strong musical bent, so I turned to an old favorite: Scott Pilgrim vs. the World, which sadly isn't available in 4K just yet. Still, for these purposes, nothing about a UHD release could possibly improve on the excellent DTS-HD Master Audio 5.1 soundtrack of the Blu-ray release. And indeed, the Gravis VI handled the movie's hard-hitting, bass-heavy audio mix well, delivering all the of chest-slamming, bone-crunching action with oodles of authority. If there's one area where its sealed design held it back to a degree, it was in the delivery of the very deepest bass, of which Scott Pilgrim has a good bit, especially in the big final battle between Scott Pilgrim and Gideon Graves.

Scott Pilgrim - Scott vs. Gideon Graves [Round 2]

Likewise, while the Gravis VI did a spectacular job of conveying all the destructive force of the explosion of Senator Amidala's ship at the beginning of Star Wars: Episode II -- Attack of the Clones, it didn't quite deliver that dental-filling-dislodging rumble of the flyover of said ship earlier in the sequence quite so well as a ported sub will. The thing is, though, as indicated above, the DSP for the Gravis VI is so well-designed that one's attention is never drawn to deep-deep-deep frequencies that it doesn't crank out quite as forcefully as it does 25 Hz and above frequencies. I honestly don't consider this a knock against the Gravis VI at all; I merely point it out as a reminder of the general performance differences between sealed and ported subs. You want tactile, lifelike, tight, and musical bass across the spectrum? This is your guy, if you can afford him. You want your britches legs to flap while watching U-571? A ported sub may be more your speed.

The Downside
We at have a policy of not knocking a product based on price, which I know is going to anger some regulars in the comments section. At $7,000, though, the Sonus faber Gravis VI is a luxury product designed for a luxury audience, and its price is more than reflected in its design and materials. And, indeed, in the nimbleness and detail of its performance.

Still, though, taking that price into consideration, the Gravis VI lacks a few niceties that I think it deserves. For one thing, I would like to see a subwoofer of this caliber ship with its own measurement mic. Even a Dayton Audio EMM-6, low-priced as it is, would be an improvement over the mics built into smartphones, and would provide better calibration.

Unrelated to price, I also wish there were a bit more variety between the four EQ presets for the Gravis VI. While there are differences, they're so subtle that you'll likely hear more tonal shifts by leaning your head back and forth a foot or so. Only the Streaming Mode preset differs substantially from the other three, with a decent boost around 50 Hz and a steeper roll-off of frequencies below 30 Hz. I'm not really sure what that has to do with streaming, but there you have it.

A Note on Measurements
We've made a habit of offering CEA-2010 measurements with our high-end subwoofer reviews, but unfortunately the fates were against me this go-around. Or, more accurately, the elements. In my first attempt at measuring the sub, I discovered a problem with my mic calibrator, which needed to be replaced. Once the new calibrator arrived, meteorological conditions prevented me from measuring the subwoofer properly in a reasonable amount of time. In addition to the sweltering heat and violent thunderstorms, we've also found ourselves in the middle of a particularly noisy annual cicada outbreak here that elevates background noise levels far above what's allowed by CEA-2010. In my last attempt, I measured the chirping, screeching, unceasing drone of the cicadas at an ear-splitting 88dB.

Sonus faber was kind enough to provide its own CEA-2010 analysis of the sub, though, which I'm including below, though with the caveat that I have not corroborated the results on my end.


I should add that in my preparation to measure the Gravis VI, I struggled with how best to position and mic it, and also whether to go with one-meter or my usual two-meter measuring distance. The driver configuration, combined with the fact that the down-firing driver doesn't simply fire straight downward, but rather interacts with the subwoofer's plinth, makes for some interesting room interactions that would be difficult to capture with a single mic from a single measurement position.

Sonus faber's engineers agreed and conveyed the following to me in our discussions: "Due to the down firing of one of the two drivers, its contribution as seen from any direction is reduced by the fact that the emission is omnidirectional in the horizontal plane. Therefore, the presented results, measured at 2m from the enclosure with the front driver facing to the microphone, should be compensated for it. A reasonable value is 2 dB (to be added)."

I actually think that's a somewhat conservative compensation, but I'm still learning here, and this is slightly above my pay-grade. At any rate, for a sealed sub with twelve-inch drivers, the indicated output--especially at 25 Hz and above--is admirable.

Comparison and Competition
As mentioned above, one obvious competitor for the Gravis VI is JL Audio's f212v2, which similarly relies on a dual-12-inch driver configuration, though a very differently positioned one. Both of the f212v2's drivers are forward firing, and the cabinet sports a much more conventional subwoofer design and finish. The f212v2 does benefit from JL Audio's Digital Automatic Room Optimization, though, and includes a calibrated measurement mic.

Paradigm's $10,500 SUB 2, a 4,500-watt behemoth with six radially aligned ten-inch drivers in a sealed cabinet, is a pricier option, but not so much so that it's unfair competition. Taste being subjective and all that, I don't think anyone would claim that the SUB 2 quite matches the Sonus faber in terms of styling and refinement, but it's an unusual and compact design that I quite dig. The SUB 2 also cranks out some stupid levels of output and extension, hitting a reported 112 dB at 10 Hz and 126 dB at 60 Hz.

If you're shopping around in cost-no-object territory, another sub to consider might be Funk Audio's 21.0, another Canadian-designed and -built bass powerhouse that features a sumptuous Baltic birch cabinet and veneers that range from curly walnut to a stunning tiger-striped maple. Granted, its design is a little more traditional than the Gravis VI, and it lacks that stunning spaghetti-string grille. But it does boast a gargantuan 21-inch driver (in a cabinet that measures only 22.25 inches wide by 22.75 inches high), and reported output of 126 dB at 63 Hz. Prices range from $8,000.00 to $8,300.00 depending on your choice of finish and add-ons.

As I box up the Gravis VI and prepare to return it to Sonus faber, I do so with a pang of jealousy. Although it's perhaps not the right subwoofer for my home cinema system, given the arrangement of my room and my penchant for the very deepest registers of sub-sonic bass, I would punch a baby koala in the neck if it meant I could keep this beauty around for my dedicated stereo system at the back of the house.

And that desire isn't driven wholly by performance. I need to state it again for the record: The Gravis VI is simply the most gorgeous, most beautifully built piece of AV gear to ever enter my home, and to be blunt about it, the sub simply classes up the joint. That is in part due to its distinctive grille design, certainly. But it's more down to the refinement of its leather wrapped cabinet and the polish of its wenge cap. Frankly, I've rarely seen this level of fit and finish in the audio world, especially not in the subwoofer. What it most reminded me of was the time I got to sit behind the wheel of a late-30s Packard sedan, with its hand-crafted wood dashboard and perfectly symmetrical instrumentation panel, perfectly restored to (probably better than) like-new condition.

If that kind of thing tickles your giggle-maker, and assuming you have the budget, I'd strongly suggest finding a Sonus faber showroom within reasonable driving distance and auditioning this luxurious beast for yourself.

Additional Resources
• Visit the Sonus faber website for more product information.
• Check out our Subwoofer category page to read similar reviews.
"Is It Live or Is It Memorex?" Sonus faber Style at

  • Scott Strother
    2021-06-25 13:17:02

    I really liked enjoyed this review, Dennis. Sf is a true leader in luxurious audio craftsmanship, and my dream system would automatically include a pair of Gravis VIs augmenting a pair of Paradigm Persona B's in a Luxman, TAD, Accuphase, and Spectral mosh-up to just die for!

  • Phil Davis
    2019-09-10 19:27:31

    As you watch a many of you look at your subwoofer.....I have two and I don't look at them at all.....

  • dougie_s
    2019-09-10 18:10:44

    when you can get much better performance for 1/3 the cost, it's really hard to see how this gets a positive recommendation. doug s.

  • Michael Rossmaessler
    2019-09-10 07:37:36

    I was introduced to cicadas this Summer. They are loud little suckers aren't they. Thanks for the review Dennis.

  • Anthony Wright
    2019-09-09 12:39:49

    Hey Dennis, Long time no speak! I enjoyed your review. Sonus Faber is in a league by itself aesthetically. While I've never heard a Sonus Faber product that sounded bad, in fact every demo I've heard, even from their cheapest lines (Chameleon, Venere, Principia) has been excellent, but the sound has never made me as irrational as the looks do. Which is mildly annoying, because I want to want their products in an absolute way. Its kind of how I imagine owning an NSX from the 90's would be. "Man, what a beautiful car." "Yea, its gorgeous, but its only got 280 horsepower😑." Nothing other than "the last word" in performance (or at least what one could convince himself is) will do for an audio-obsessive, unfortunately, and for their prices, they would need to be the last set of speakers I buy for a decade. All i could think about while I was reading your review was, "I wonder how awesome two of those subs would be in that room", hahaha. Lastly, props to Sonus Faber for going class AB, for whatever reason. I like seeing brands break from the herd. See ya!

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