In this review, we will be comparing KUBE 12b and ASW608, 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 ASW608 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 ASW608 have a single woofer setup however the KEF KUBE 12b's woofer is 12-inch whereas the B&W ASW608 features a 8-inch woofer.
Frequency Response
KUBE 12b has a frequency range of 22-140 Hz whereas ASW608 has a frequency range of 32-140 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 ASW608's min frequency of 32Hz.
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 ASW608 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 ASW608'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 ASW608 has external dimensions of 272.0 x 261.0 x 350.0mm (10-11/16 x 10-1/4 x 13-3/4inch).
KEF KUBE 12b is clearly the larger of the two speakers. Its body is 135mm wider, 138mm taller and 92mm deeper than B&W ASW608.
Below you can see the front view size comparison of KEF KUBE 12b and B&W ASW608 in scale.
Comparison image of KEF KUBE 12b and B&W ASW608 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 B&W ASW608 is approximately 913.5cm2 / 141.6inch2. The KUBE 12b requires 92% more surface area than the ASW608 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 ASW608 weighs 8.86kg / 19.5lbs. This makes the KUBE 12b 133% heavier than the ASW608.
Here is a comparison of how KUBE 12b and ASW608'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 ASW608?
Here are the items that come with the ASW608:
- Powered subwoofer
- Grille
- 6.5-feet AC power cord
- 4 Rubber feet
- 4 Spike feet
- 4 Lock-nuts
- Manual
- Bowers & Wilkins brochure
- Warranty Information
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
22 Hz
vs
32 Hz
|
Generates deeper bass |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
 Height |
272mm
vs
410mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
913cm2
vs
1750cm2
|
Takes less floor space |
 Price per pair* |
599USD
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 92% more floor area. KEF KUBE 12b stands 92mm further into the room. KEF KUBE 12b is 138mm taller.
| General |
KEF KUBE 12b |
Bowers & Wilkins ASW608 |
| Brand |
KEF |
Bowers Wilkins |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
200 watts |
| Frequency Response |
22-140 Hz |
32-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
200-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
8" |
| Woofer Composition |
|
Paper/Aramid Fiber |
| 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") |
272.0mm (10.7") |
| Width |
396.0mm (15.6") |
261.0mm (10.3") |
| Depth |
442.0mm (17.4") |
350.0mm (13.8") |
| Weight |
20.68kg (45.5lbs) |
8.86kg (19.5lbs) |
| 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 |
Two quite different sizes of subwoofer. Room volume decides this more than anything else on the page: a big driver in a small room is wasted, and a small one in a large room is worked to death.
| Area | Better | Why |
|---|
| Bass depth | A | KEF KUBE 12b goes deeper - 22Hz against 32Hz. That gap covers the lowest notes of a five-string bass and a concert bass drum. |
| Amplifier power | A | KEF KUBE 12b has the bigger amplifier - 300W against 200W RMS, about 1.8dB 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 | evenly matched | Both are sealed designs, so they roll off in much the same way. |
| Speaker-level inputs | B | B&W ASW608 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 | B&W ASW608 is about 65% 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 | B | B&W ASW608 costs less - $599 against $900, about 33% less. |
A KEF KUBE 12b B B&W ASW608
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?
The usual trade-off: KEF KUBE 12b measures better, B&W ASW608 costs about 33% less. In a normal room, placement will make a bigger difference than the gap between these two. Check your amplifier first: if it has no subwoofer or preamp output, B&W ASW608 is the only one of these two you can connect at all. If placement is the constraint - a corner, behind a sofa, under a desk - B&W ASW608 is the one that will actually go there, and a well-placed small subwoofer beats a badly-placed big one every time.
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.