In this review, we will be comparing Gravis II and KUBE 10b, two Powered Subwoofer speakers from Sonus faber and KEF. 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 KEF KUBE 10b 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.
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Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Sonus faber Gravis IIand KEF KUBE 10b have the same driver set up: Both subwoofers have 1 x 10" drivers.
Frequency Response
Gravis II has a frequency range of 25-120 Hz whereas KUBE 10b has a frequency range of 24-140 Hz. With a minimum frequency of 24Hz, the KUBE 10b can go slightly deeper then 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 KEF KUBE 10b 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 KEF KUBE 10b'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 KEF KUBE 10b has external dimensions of 372.0 x 356.0 x 397.0mm (14-5/8 x 14 x 15-5/8inch).
Sonus faber Gravis II is clearly the larger of the two speakers. Its body is 2mm wider, 35mm taller and 38mm deeper than KEF KUBE 10b.
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 KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The Gravis II requires 10% more surface area than the KUBE 10b 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 II weighs 21.50kg / 47.3lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the Gravis II 23% heavier than the KUBE 10b.
Here is a comparison of how Gravis II and KUBE 10b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of Sonus faber Gravis II?
Here are the items that are included inside the box of Gravis II:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- 33-feet Speakon cable
- Owners Manual
- Environmental Information
What's in the Box of KEF KUBE 10b?
Here are the items that come with the KUBE 10b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
 Passive Radiator |
2 x 10-inch
vs
None
|
Increases the bass performance |
 Low Frequency Response |
24 Hz
vs
25 Hz
|
Generates deeper bass |
 High Frequency Response |
140k Hz
vs
120k Hz
|
Generates higher frequency |
 Height |
372mm
vs
407mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1413cm2
vs
1557cm2
|
Takes less floor space |
 Price per pair* |
750USD
vs
1499USD
|
costs less (*prices may change depending on the seller, location and time) |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| General |
Sonus faber Gravis II |
KEF KUBE 10b |
| Brand |
Sonus faber |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
350 watts |
300 watts |
| Frequency Response |
25-120 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
350-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
10" |
| Woofer Composition |
Treated Paper |
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
407.0mm (16") |
372.0mm (14.6") |
| Width |
358.0mm (14.1") |
356.0mm (14") |
| Depth |
435.0mm (17.1") |
397.0mm (15.6") |
| Weight |
21.50kg (47.3lbs) |
17.50kg (38.5lbs) |
| Enclosure |
Passive Radiator |
Acoustic Suspension |
| Available Colors |
Piano Black,Matte White |
n/a |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Yr/3 Yr registered |
2 Years |
| Labor Warranty |
2 Yr/3 Yr registered |
2 Years |