In this review, we will be comparing Gravis III and Gravis I, 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 III and Sonus faber Gravis I 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.Both Sonus faber Gravis IIIand Sonus faber Gravis I have a single woofer setup however the Sonus faber Gravis III's woofer is 10-inch whereas the Sonus faber Gravis I features a 8-inch woofer.
Frequency Response
Gravis III has a frequency range of 25-120 Hz whereas Gravis I has a frequency range of 30-120 Hz. With a minimum frequency of 25Hz, the Gravis III can go significantly deeper on the low side and provide stronger bass compared to the Gravis I's min frequency of 30Hz.
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 III and Sonus faber Gravis I 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 III's and Sonus faber Gravis I's external dimensions. 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) whereas Sonus faber Gravis I has external dimensions of 337.0 x 286.0 x 340.0mm (13-1/4inch x 11-1/4inch x 13-3/8inch).
Sonus faber Gravis III is clearly the larger of the two speakers. Its body is 114mm wider, 78mm taller and 155mm deeper than Sonus faber Gravis I.
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 III needs about 104% more floor or shelf area. Sonus faber Gravis III is 155mm deeper, so it stands that much further out from the wall. Sonus faber Gravis III is 78mm 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 III is approximately 1980.0cm2 / 306.9inch2 and base area of the Sonus faber Gravis I is approximately 972.4cm2 / 150.7inch2. The Gravis III requires 104% more surface area than the Gravis I 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 III weighs 26.70kg / 58.7lbs and the Sonus faber Gravis I weighs 14.55kg / 32lbs. This makes the Gravis III 84% heavier than the Gravis I.
Here is a comparison of how Gravis III and Gravis I's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Woofer Size |
10 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
25 Hz
vs
30 Hz
|
Generates deeper bass |
 Height |
337mm
vs
415mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
972cm2
vs
1980cm2
|
Takes less floor space |
 Price per pair* |
999USD
vs
2700USD
|
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 III needs about 104% more floor area. Sonus faber Gravis III stands 155mm further into the room. Sonus faber Gravis III is 78mm taller.
| General |
Sonus faber Gravis III |
Sonus faber Gravis I |
| Brand |
Sonus faber |
Sonus faber |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
600 watts |
150 watts |
| Frequency Response |
25-120 Hz |
30-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
600-watt RMS |
150-watt RMS |
| Watts Peak (Max) |
900-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
8" |
| Woofer Composition |
Honeycomb sandwich |
Treated Paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
Continuously adjustable |
n/a |
| Firing Direction |
n/a |
bottom |
Physical Specs |
|
|
| Height |
415.0mm (16.3") |
337.0mm (13.3") |
| Width |
400.0mm (15.7") |
286.0mm (11.3") |
| Depth |
495.0mm (19.5") |
340.0mm (13.4") |
| Weight |
26.70kg (58.7lbs) |
14.55kg (32lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Available Colors |
n/a |
Piano Black,Matte White |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
2 Yr/3 Yr registered |
| Labor Warranty |
|
2 Yr/3 Yr registered |
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 III goes deeper - 25Hz against 30Hz. That gap covers the lowest notes of a five-string bass and a concert bass drum. |
| Amplifier power | A | Sonus faber Gravis III has the bigger amplifier - 600W against 150W RMS, about 6dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | Sonus faber Gravis III moves more air: 10" against 8" is 1.56x the cone area, not the 1.25x 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. |
| Driver placement | depends | Sonus faber Gravis III fires front and Sonus faber Gravis I fires down. 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 I is about 60% 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 I costs less - $999 against $2,700, about 63% less. |
A Sonus faber Gravis III B Sonus faber Gravis I
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 III measures better, Sonus faber Gravis I costs about 63% 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 $999 each, two Sonus faber Gravis I cost about $1,998 against $2,700 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 I 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.