In this review, we will be comparing Gravis I 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 I and KEF KUBE 10b first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the Sonus faber Gravis I and KEF KUBE 10b compare and hopefully end up with enough arguments to decide which one of these subwoofers is the better choice for you.
**This post contains affiliate links, and I will be compensated if you make a purchase after clicking through my links. As an Amazon Associate I earn from qualifying purchases.
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 Iand KEF KUBE 10b have a single woofer setup however the Sonus faber Gravis I's woofer is 8-inch whereas the KEF KUBE 10b features a 10-inch woofer.
Frequency Response
Gravis I has a frequency range of 30-120 Hz whereas KUBE 10b has a frequency range of 24-140 Hz. With a minimum frequency of 24Hz, the KUBE 10b 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 I and KEF KUBE 10b 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
Size of a speaker can sometimes become 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 I's and KEF KUBE 10b's external dimensions. 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 ) 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) .
KEF KUBE 10b is clearly the larger of the two speakers. Its body is 70mm wider, 35mm taller and 57mm deeper than Sonus faber Gravis I.
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 I is approximately 972.4cm2 / 150.7inch2 and base area of the KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The Gravis I requires 31% less surface area than the KUBE 10b 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 I weighs 14.55kg / 32lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the KUBE 10b 20% heavier than the Gravis I.
Here is a comparison of how Gravis I 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 I?
Here are the items that are included inside the box of Gravis I:
Powered subwoofer6-feet AC power cord33-feet Speakon cableOwners ManualEnvironmental Information
What's in the Box of KEF KUBE 10b?
Here are the items that come with the KUBE 10b:
Powered subwoofer6.5-feet AC power cordSpeaker-level input blockUser ManualImportant Safety InformationWarranty Information
 Height |
337mm
vs
372mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
972cm2
vs
1413cm2
|
Takes less floor space |
 Driver Setup |
1-way
vs
-way
|
Have a dedicated mid-range driver |
 Woofer Size |
10 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
30 Hz
|
Generates deeper bass |
 High Frequency Response |
140k Hz
vs
120k Hz
|
Generates higher frequency |
 Price per pair* |
750USD
vs
999USD
|
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 I |
KEF KUBE 10b |
| Brand |
Sonus Faber |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
150 watts |
300 watts |
| Frequency Response |
30-120 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
150-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
10" |
| Woofer Composition |
Treated Paper |
Not given |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
bottom |
front |
Physical Specs |
|
|
| Height |
337.0mm (13.3") |
372.0mm (14.6") |
| Width |
286.0mm (11.3") |
356.0mm (14") |
| Depth |
340.0mm (13.4") |
397.0mm (15.6") |
| Weight |
14.55kg (32lbs) |
17.50kg (38.5lbs) |
| Enclosure |
Acoustic Suspension |
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 |