In this review, we will be comparing KUBE 12b and KUBE 8b, two Powered Subwoofer speakers by 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 KEF KUBE 12b and KEF KUBE 8b 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.Both KEF KUBE 12band KEF KUBE 8b have a single woofer setup however the KEF KUBE 12b's woofer is 12-inch whereas the KEF KUBE 8b features a 8-inch woofer.
Frequency Response
KUBE 12b has a frequency range of 22-140 Hz whereas KUBE 8b has a frequency range of 34-140 Hz. With a minimum frequency of 22Hz, the KUBE 12b 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
Both KEF KUBE 12b and KEF KUBE 8b 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 KEF KUBE 12b's and KEF KUBE 8b's external dimensions. KEF KUBE 12b has external dimensions of 410.0 x 396.0 x 442.0mm (16-1/8 x 15-9/16 x 17-3/8inch) whereas 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).
KEF KUBE 12b is clearly the larger of the two speakers. Its body is 100mm wider, 116mm taller and 103mm deeper than KEF KUBE 8b.
Below you can see the front view size comparison of KEF KUBE 12b and KEF KUBE 8b in scale.
Comparison image of KEF KUBE 12b and KEF KUBE 8b 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 12b is approximately 1750.3cm2 / 271.3inch2 and base area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2. The KUBE 12b requires 74% more surface area than the KUBE 8b 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 KEF KUBE 12b weighs 20.68kg / 45.5lbs and the KEF KUBE 8b weighs 11.36kg / 25lbs. This makes the KUBE 12b 82% heavier than the KUBE 8b.
Here is a comparison of how KUBE 12b and KUBE 8b'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 12b?
Here are the items that are included inside the box of KUBE 12b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
What's in the Box of KEF KUBE 8b?
Here are the items that come with the KUBE 8b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
22 Hz
vs
34 Hz
|
Generates deeper bass |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
 Height |
294mm
vs
410mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
1750cm2
|
Takes less floor space |
 Price per pair* |
600USD
vs
900USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF KUBE 12b |
KEF KUBE 8b |
| Brand |
KEF |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
300 watts |
| Frequency Response |
22-140 Hz |
34-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
8" |
| Woofer Composition |
|
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
40-140 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
410.0mm (16.1") |
294.0mm (11.6") |
| Width |
396.0mm (15.6") |
296.0mm (11.7") |
| Depth |
442.0mm (17.4") |
339.0mm (13.3") |
| Weight |
20.68kg (45.5lbs) |
11.36kg (25lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
2 Years |
| Labor Warranty |
2 Years |
2 Years |