In this review, we will be comparing KUBE 8b and C 912, two Powered Subwoofer speakers from KEF and Jamo. 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 KEF KUBE 8b and Jamo C 912 first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the KEF KUBE 8b and Jamo C 912 compare and hopefully end up with enough arguments to decide which one of these subwoofers is the better choice for you.
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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.Both KEF KUBE 8band Jamo C 912 have a single woofer setup however the KEF KUBE 8b's woofer is 8-inch whereas the Jamo C 912 features a 12-inch woofer.
Frequency Response
KUBE 8b has a frequency range of 34-140 Hz whereas C 912 has a frequency range of 29-125 Hz. With a minimum frequency of 29Hz, the C 912 can go significantly deeper on the low side and provide stronger bass compared to the KUBE 8b's min frequency of 34Hz.
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 KEF KUBE 8b has a Acoustic Suspension type cabinet. 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. On the other hand the Jamo C 912 have Bass Reflex type enclosure. Bass Reflex type subwoofers (aka Ported, Vented or Reflex Port) have enclosures that uses a port, hole or vent cut into the cabinet. Ported designs are generally more efficient than the Sealed 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 KEF KUBE 8b's and Jamo C 912's external dimensions. KEF KUBE 8b has external dimensions of 294.0 x 296.0 x 339.0mm ( 11-9/16 x 11-5/8 x 13-5/16inch) whereas Jamo C 912 has external dimensions of 461.0 x 358.0 x 507.0mm ( 18-1/8 x 14-1/16 x 19-15/16inch) .
Jamo C 912 is clearly the larger of the two speakers. Its body is 62mm wider, 167mm taller and 168mm deeper than KEF KUBE 8b.
Below you can see the front view size comparison of KEF KUBE 8b and Jamo C 912 in scale.
Comparison image of KEF KUBE 8b and Jamo C 912 Size and External Dimensions
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 KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2 and base area of the Jamo C 912 is approximately 1815.1cm2 / 281.3inch2. The KUBE 8b requires 45% less surface area than the C 912 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 KEF KUBE 8b weighs 11.36kg / 25lbs and the Jamo C 912 weighs 18.98kg / 41.8lbs. This makes the C 912 67% heavier than the KUBE 8b.
Here is a comparison of how KUBE 8b and C 912's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of KEF KUBE 8b?
Here are the items that are included inside the box of KUBE 8b:
Powered subwoofer6.5-feet AC power cordSpeaker-level input blockUser ManualImportant Safety InformationWarranty Information
What's in the Box of Jamo C 912?
Here are the items that come with the C 912:
Powered subwooferGrille6-feet AC power cordUser ManualImportant Safety InstructionsWarranty Information
 High Frequency Response |
140k Hz
vs
125k Hz
|
Generates higher frequency |
 Height |
294mm
vs
461mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2 (296x339mm)
vs
1815cm2 (358x507mm)
|
Takes less floor space |
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
29 Hz
vs
34 Hz
|
Generates deeper bass |
 Price per pair* |
229USD
vs
600USD
|
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 |
KEF KUBE 8b |
Jamo C 912 |
| Brand |
KEF |
Jamo |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
200 watts |
| Frequency Response |
34-140 Hz |
29-125 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
200-watt RMS |
| Watts Peak (Max) |
n/a |
400-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
12" |
| Woofer Composition |
Not given |
IMG |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
n/a |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
294.0mm (11.6") |
461.0mm (18.1") |
| Width |
296.0mm (11.7") |
358.0mm (14.1") |
| Depth |
339.0mm (13.3") |
507.0mm (20") |
| Weight |
11.36kg (25lbs) |
18.98kg (41.8lbs) |
| Enclosure |
Acoustic Suspension |
Bass Reflex |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
2 Years |
| Labor Warranty |
2 Years |
2 Years |