In this review, we will be comparing Gravis VI and Gravis III, two Powered Subwoofer speakers by Sonus faber. Being Powered subwoofers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them. Let's have a brief look at the main features of Sonus faber Gravis VI and Sonus faber Gravis III first before getting into our more detailed comparison.
The sections below take each area in turn: driver and amplifier, frequency response, physical size and connectivity.
Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Sonus faber Gravis VI and Sonus faber Gravis III have a totally different setup: the Sonus faber Gravis VI features 2 x 12.5-inch drivers whereas the Gravis III features 1 x 10-inch drivers.
Frequency Response
Gravis VI has a frequency range of 18-120 Hz whereas Gravis III has a frequency range of 25-120 Hz. With a minimum frequency of 18Hz, the Gravis VI can go significantly deeper on the low side and provide stronger bass compared to the Gravis III's min frequency of 25Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Subwoofer class in our database.
Low Frequency
Subwoofer Speakers
High Frequency
Subwoofer Speakers
Cabinet Type
Both Sonus faber Gravis VI and Sonus faber Gravis III have Acoustic Suspension type cabinets. Acoustic Suspension aka Sealed type subwoofers have enclosures that are sealed hence no ports or holes exists on the cabinet. Sealed designs helps to provide more accurate and tight bass responses compared to ported designs.
Physical Specs
The size of a speaker can sometimes be an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare Sonus faber Gravis VI's and Sonus faber Gravis III's external dimensions. Sonus faber Gravis VI has external dimensions of 616.0 x 448.0 x 585.0mm (24-1/4 x 17-5/8 x 23-1/16inch) whereas Sonus faber Gravis III has external dimensions of 415.0 x 400.0 x 495.0mm (16-5/16 x 15-3/4 x 19-1/2inch).
Sonus faber Gravis VI is clearly the larger of the two speakers. Its body is 48mm wider, 201mm taller and 90mm deeper than Sonus faber Gravis III.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
Sonus faber Gravis VI needs about 32% more floor or shelf area. Sonus faber Gravis VI is 90mm deeper, so it stands that much further out from the wall. Sonus faber Gravis VI is 201mm taller.
Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base surface area of the Sonus faber Gravis VI is approximately 2620.8cm2 / 406.2inch2 and base area of the Sonus faber Gravis III is approximately 1980.0cm2 / 306.9inch2. The Gravis VI requires 32% more surface area than the Gravis III which gives it a small disadvantage on placement in tight spaces.
Weight Comparison The weight of a subwoofer may become an important factor if you need to move and reposition the unit often to find the optimal positioning, also known as 'Subwoofer Crawling'. The Sonus faber Gravis VI weighs 52.00kg / 114.4lbs and the Sonus faber Gravis III weighs 26.70kg / 58.7lbs. This makes the Gravis VI 95% heavier than the Gravis III.
Here is a comparison of how Gravis VI and Gravis III's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Woofer Size |
12.5 inches
vs
10 inches
|
Larger woofer |
| Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
18 Hz
vs
25 Hz
|
Generates deeper bass |
 Height |
415mm
vs
616mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1980cm2
vs
2620cm2
|
Takes less floor space |
 Price per pair* |
2700USD
vs
6500USD
|
costs less (*prices may change depending on the seller, location and time) |
Size, drawn to scale
Both subwoofers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same floor and pushed back to the same wall, so the bigger one visibly takes more of the room.
Sonus faber Gravis VI needs about 32% more floor area. Sonus faber Gravis VI stands 90mm further into the room. Sonus faber Gravis VI is 201mm taller.
| General |
Sonus faber Gravis VI |
Sonus faber Gravis III |
| Brand |
Sonus faber |
Sonus faber |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
1700 watts |
600 watts |
| Frequency Response |
18-120 Hz |
25-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
1700-watt RMS |
600-watt RMS |
| Watts Peak (Max) |
2400-watt RMS |
900-watt RMS |
Drivers |
|
|
| Woofer Quantity |
2 |
1 |
| Woofer Size |
12.5" |
10" |
| Woofer Composition |
Honeycomb sandwich |
Honeycomb sandwich |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
Continuously adjustable |
Continuously adjustable |
Physical Specs |
|
|
| Height |
616.0mm (24.3") |
415.0mm (16.3") |
| Width |
448.0mm (17.6") |
400.0mm (15.7") |
| Depth |
585.0mm (23") |
495.0mm (19.5") |
| Weight |
52.00kg (114.4lbs) |
26.70kg (58.7lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
|
| Labor Warranty |
|
|
Siblings in Sonus faber's Gravis range - same design thinking, different size. It comes down to your room and your budget.
| Area | Better | Why |
|---|
| Bass depth | A | Sonus faber Gravis VI goes deeper - 18Hz against 25Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | Sonus faber Gravis VI has the bigger amplifier - 1700W against 600W RMS, about 4.5dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | Sonus faber Gravis VI moves more air: 2 x 12.5" against 10" is 3.13x the cone area, not the 1.77x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | evenly matched | Both are sealed designs, so they roll off in much the same way. |
| Cabinet size | depends | Sonus faber Gravis III is about 49% smaller by volume. In a subwoofer that is a real trade rather than a preference: box volume is how you get output low down without a bigger amplifier. |
| Price | B | Sonus faber Gravis III costs less - $2,700 against $6,500, about 58% less. |
A Sonus faber Gravis VI B Sonus faber Gravis III
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both subwoofers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
The usual trade-off: Sonus faber Gravis VI measures better, Sonus faber Gravis III costs about 58% less. In a normal room, placement will make a bigger difference than the gap between these two. Two small subwoofers beat one big one in most rooms - a pair evens out the room modes in a way no single box can, whatever its specs. At $2,700 each, two Sonus faber Gravis III cost about $5,400 against $6,500 for one of the other, which is worth a thought. If placement is the constraint - a corner, behind a sofa, under a desk - Sonus faber Gravis III is the one that will actually go there, and a well-placed small subwoofer beats a badly-placed big one every time.
One thing outweighs everything above: where the subwoofer stands. Room modes can add or remove 10dB or more at a given seat, which is far larger than any difference on this page. Before spending more, try the sub in two or three positions - the crawl test, where you put it in the listening seat and crawl the room to find where the bass sounds best, costs nothing and usually beats an upgrade.