In this review, we will be comparing KUBE 12b and SuperCube 4000, two Powered Subwoofer speakers from KEF and Definitive Technology. 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 DT SuperCube 4000 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 KEF KUBE 12band DT SuperCube 4000 have a single woofer setup however the KEF KUBE 12b's woofer is 12-inch whereas the DT SuperCube 4000 features a 8-inch woofer.
Frequency Response
KUBE 12b has a frequency range of 22-140 Hz whereas SuperCube 4000 has a frequency range of 16-200 Hz. With a minimum frequency of 16Hz, the SuperCube 4000 can go significantly deeper on the low side and provide stronger bass compared to the KUBE 12b's min frequency of 22Hz.
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 12b 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 DT SuperCube 4000 have Passive Radiator type enclosure. 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.
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 DT SuperCube 4000'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 DT SuperCube 4000 has external dimensions of 302.0 x 281.0 x 318.0mm (11-7/8 x 11-1/16 x 12-1/2inch).
KEF KUBE 12b is clearly the larger of the two speakers. Its body is 115mm wider, 108mm taller and 124mm deeper than DT SuperCube 4000.
Below you can see the front view size comparison of KEF KUBE 12b and DT SuperCube 4000 in scale.
Comparison image of KEF KUBE 12b and DT SuperCube 4000 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 DT SuperCube 4000 is approximately 893.6cm2 / 138.5inch2. The KUBE 12b requires 96% more surface area than the SuperCube 4000 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 DT SuperCube 4000 weighs 11.36kg / 25lbs. This makes the KUBE 12b 82% heavier than the SuperCube 4000.
Here is a comparison of how KUBE 12b and SuperCube 4000'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 DT SuperCube 4000?
Here are the items that come with the SuperCube 4000:
- 8-inch Powered subwoofer
- 7-feet AC power cord
- Remote control (CR2025 battery installed)
- 4 Threaded rubber-feet
- 4 Spike feet (hex-nut attached)
- Owners Manual
- SC4000 Booklet
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| Low Frequency Response |
16 Hz
vs
22 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
140 Hz
|
Generates higher frequency |
 Height |
302mm
vs
410mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
893cm2
vs
1750cm2
|
Takes less floor space |
 Price per pair* |
799USD
vs
900USD
|
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.
KEF KUBE 12b needs about 96% more floor area. KEF KUBE 12b stands 124mm further into the room. KEF KUBE 12b is 108mm taller.
| General |
KEF KUBE 12b |
Definitive Technology SuperCube 4000 |
| Brand |
KEF |
Definitive Technology |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
1200 watts |
| Frequency Response |
22-140 Hz |
16-200 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
1200-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 |
40-150 Hz and 40-150 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
410.0mm (16.1") |
302.0mm (11.9") |
| Width |
396.0mm (15.6") |
281.0mm (11.1") |
| Depth |
442.0mm (17.4") |
318.0mm (12.5") |
| Weight |
20.68kg (45.5lbs) |
11.36kg (25lbs) |
| Enclosure |
Acoustic Suspension |
Passive Radiator |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
3 Years |
| Labor Warranty |
2 Years |
3 Years |
A sealed subwoofer against a passive radiator one. That is the most consequential line on this page: it decides how the bass rolls off, how it behaves in a small room, and how much output you get for the size of the box.
| Area | Better | Why |
|---|
| Bass depth | B | DT SuperCube 4000 goes deeper - 16Hz against 22Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | B | DT SuperCube 4000 has the bigger amplifier - 1200W against 300W RMS, about 6dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | KEF KUBE 12b moves more air: 12" against 8" is 2.25x the cone area, not the 1.5x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | KEF KUBE 12b is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; DT SuperCube 4000 is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Speaker-level inputs | B | DT SuperCube 4000 takes a speaker-level connection as well as line level. That is what lets it work with an integrated amplifier or a vintage receiver that has no subwoofer output at all. |
| Wireless option | depends | Only KEF KUBE 12b offers a wireless link (as a paid option). It decides where the sub can go if you cannot run a cable, and is worth nothing if you can. |
| Cabinet size | depends | DT SuperCube 4000 is about 62% 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. |
| Warranty | B | DT SuperCube 4000 carries 3 years on parts against 2 years. A subwoofer amplifier works harder than anything else in the system, so this is not a throwaway line. |
| Price | B | DT SuperCube 4000 costs less - $799 against $900, about 11% less. |
A KEF KUBE 12b B DT SuperCube 4000
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?
DT SuperCube 4000 is the easier recommendation: it leads on most of the measured areas and costs less. Take KEF KUBE 12b if one of the "depends" rows describes your room. Films or music? If this is mainly a home cinema, DT SuperCube 4000 will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KUBE 12b is usually the easier one to make sound right. Check your amplifier first: if it has no subwoofer or preamp output, DT SuperCube 4000 is the only one of these two you can connect at all.
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.