In this review, we will be comparing KUBE 12b and DB4S, two Powered Subwoofer speakers from KEF and Bowers Wilkins. 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 B&W DB4S 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 B&W DB4S have a single woofer setup however the KEF KUBE 12b's woofer is 12-inch whereas the B&W DB4S features a 10-inch woofer.
Frequency Response
KUBE 12b has a frequency range of 22-140 Hz whereas DB4S has a frequency range of 10-350 Hz. With a minimum frequency of 10Hz, the DB4S 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
Both KEF KUBE 12b and B&W DB4S 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 B&W DB4S'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 B&W DB4S has external dimensions of 375.0 x 362.0 x 434.0mm (14-3/4 x 14-1/4 x 17-1/16inch).
KEF KUBE 12b is clearly the larger of the two speakers. Its body is 34mm wider, 35mm taller and 8mm deeper than B&W DB4S.
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 B&W DB4S is approximately 1571.1cm2 / 243.5inch2. The KUBE 12b requires 11% more surface area than the DB4S 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 B&W DB4S weighs 26.05kg / 57.3lbs. This makes the DB4S 26% heavier than the KUBE 12b.
Here is a comparison of how KUBE 12b and DB4S'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 B&W DB4S?
Here are the items that come with the DB4S:
- Powered subwoofer
- Grille
- 6.5-feet AC power cord
- 4 Decoupling feet
- 4 Rubber feet
- 4 Spike feet
- 4 Lock-nuts
- Cleaning cloth
- Quickstart Guide
- Bowers & Wilkins brochure
- Warranty Information
- Cleaning cloth instructions
 Woofer Size |
12 inches
vs
10 inches
|
Larger woofer |
 Price per pair* |
900USD
vs
2199USD
|
costs less (*prices may change depending on the seller, location and time) |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| Low Frequency Response |
10 Hz
vs
22 Hz
|
Generates deeper bass |
 High Frequency Response |
350 Hz
vs
140 Hz
|
Generates higher frequency |
 App-Based Control |
iOS,Android
vs
None
|
Control the speaker via an app |
 Height |
375mm
vs
410mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1571cm2
vs
1750cm2
|
Takes less floor space |
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 11% more floor area. KEF KUBE 12b is 35mm taller.
| General |
KEF KUBE 12b |
Bowers & Wilkins DB4S |
| Brand |
KEF |
Bowers Wilkins |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
1000 watts |
| Frequency Response |
22-140 Hz |
10-350 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
10" |
| Woofer Composition |
|
Aerofoil |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
n/a |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
410.0mm (16.1") |
375.0mm (14.8") |
| Width |
396.0mm (15.6") |
362.0mm (14.3") |
| Depth |
442.0mm (17.4") |
434.0mm (17.1") |
| Weight |
20.68kg (45.5lbs) |
26.05kg (57.3lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
2 Years |
| Labor Warranty |
2 Years |
2 Years |
Different price classes - B&W DB4S costs roughly 2.4x what KEF KUBE 12b does. Before paying it, read the note below about two smaller subwoofers.
| Area | Better | Why |
|---|
| Bass depth | B | B&W DB4S goes deeper - 10Hz 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 | B&W DB4S has the bigger amplifier - 1000W against 300W RMS, about 5.2dB 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 10" is 1.44x the cone area, not the 1.2x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | evenly matched | Both are sealed designs, so they roll off in much the same way. |
| 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 | B&W DB4S is about 18% 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. |
| Price | A | KEF KUBE 12b costs less - $900 against $2,199, about 59% less. |
A KEF KUBE 12b B B&W DB4S
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?
B&W DB4S is ahead, but on only 1 of the measured areas, and it costs about 144% more. KEF KUBE 12b is the sensible buy unless your room is large enough to need the extra. Two small subwoofers beat one big one in most rooms - a pair evens out the room modes in a way no single box can, whatever its specs. At $900 each, two KEF KUBE 12b cost about $1,800 against $2,199 for one of the other, which is worth a thought.
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.