In this review, we will be comparing Gravis II and Gravis VI, 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 II and Sonus faber Gravis VI 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 II and Sonus faber Gravis VI have a totally different setup: the Sonus faber Gravis II features 1 x 10-inch drivers whereas the Gravis VI features 2 x 12.5-inch drivers.
Frequency Response
Gravis II has a frequency range of 25-120 Hz whereas Gravis VI has a frequency range of 18-120 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 II'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
The Sonus faber Gravis II has a Passive Radiator type cabinet. Passive Radiator type subwoofers sports a non-powered cone that moves in response to the main woofer to move air out in order to generate stronger bass in a smaller body compared to ported or sealed designs. On the other hand the Sonus faber Gravis VI have Acoustic Suspension type enclosure. 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 II's and Sonus faber Gravis VI's external dimensions. Sonus faber Gravis II has external dimensions of 407.0 x 358.0 x 435.0mm (16inch x 14-1/16inch x 17-1/8inch) whereas 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).
Sonus faber Gravis VI is clearly the larger of the two speakers. Its body is 90mm wider, 209mm taller and 150mm deeper than Sonus faber Gravis II.
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 68% more floor or shelf area. Sonus faber Gravis VI is 150mm deeper, so it stands that much further out from the wall. Sonus faber Gravis VI is 209mm 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 II is approximately 1557.3cm2 / 241.4inch2 and base area of the Sonus faber Gravis VI is approximately 2620.8cm2 / 406.2inch2. The Gravis II requires 41% less surface area than the Gravis VI which gives it a small advantage 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 II weighs 21.50kg / 47.3lbs and the Sonus faber Gravis VI weighs 52.00kg / 114.4lbs. This makes the Gravis VI 142% heavier than the Gravis II.
Here is a comparison of how Gravis II and Gravis VI's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Passive Radiator |
2 x 10-inch
vs
None
|
Increases the bass performance |
 Height |
407mm
vs
616mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1557cm2
vs
2620cm2
|
Takes less floor space |
 Price per pair* |
1499USD
vs
6500USD
|
costs less (*prices may change depending on the seller, location and time) |
 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 |
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 68% more floor area. Sonus faber Gravis VI stands 150mm further into the room. Sonus faber Gravis VI is 209mm taller.
| General |
Sonus faber Gravis II |
Sonus faber Gravis VI |
| Brand |
Sonus faber |
Sonus faber |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
350 watts |
1700 watts |
| Frequency Response |
25-120 Hz |
18-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
350-watt RMS |
1700-watt RMS |
| Watts Peak (Max) |
n/a |
2400-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
10" |
12.5" |
| Woofer Composition |
Treated Paper |
Honeycomb sandwich |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
Continuously adjustable |
| Firing Direction |
front |
n/a |
Physical Specs |
|
|
| Height |
407.0mm (16") |
616.0mm (24.3") |
| Width |
358.0mm (14.1") |
448.0mm (17.6") |
| Depth |
435.0mm (17.1") |
585.0mm (23") |
| Weight |
21.50kg (47.3lbs) |
52.00kg (114.4lbs) |
| Enclosure |
Passive Radiator |
Acoustic Suspension |
| Available Colors |
Piano Black,Matte White |
n/a |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Yr/3 Yr registered |
|
| Labor Warranty |
2 Yr/3 Yr registered |
|
A passive radiator subwoofer against a sealed one. That is the most consequential line on this page: it decides how the bass rolls off, how it behaves in a small room, and how much output you get for the size of the box.
| Area | Better | Why |
|---|
| Bass depth | B | 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 | B | Sonus faber Gravis VI has the bigger amplifier - 1700W against 350W RMS, about 6.9dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | B | 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 | depends | Sonus faber Gravis II is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet; Sonus faber Gravis VI is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Driver placement | depends | Sonus faber Gravis II fires front/down and Sonus faber Gravis VI fires front. A down-firing driver is more forgiving of a grille-less look and of a hard floor; a front-firing one is the safer choice on a thick carpet or a suspended timber floor. |
| Cabinet size | depends | Sonus faber Gravis II is about 61% 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 | A | Sonus faber Gravis II costs less - $1,499 against $6,500, about 77% less. |
A Sonus faber Gravis II B Sonus faber Gravis VI
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 II costs about 77% less. In a normal room, placement will make a bigger difference than the gap between these two. Films or music? If this is mainly a home cinema, Sonus faber Gravis II will hit harder for the money; if it is mainly for music in a normal-sized room, Sonus faber Gravis VI is usually the easier one to make sound right. 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 $1,499 each, two Sonus faber Gravis II cost about $2,998 against $6,500 for one of the other, which is worth a thought.
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.