In this review, we will be comparing KC62 and KUBE 12b, 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 KC62 and KEF KUBE 12b 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.KEF KC62 and KEF KUBE 12b have a totally different setup: the KEF KC62 features 2 x 6.5-inch drivers whereas the KUBE 12b features 1 x 12-inch drivers.
Frequency Response
KC62 has a frequency range of 11-200 Hz whereas KUBE 12b has a frequency range of 22-140 Hz. With a minimum frequency of 11Hz, the KC62 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 KC62 and KEF KUBE 12b 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 KC62's and KEF KUBE 12b's external dimensions. KEF KC62 has external dimensions of 245.0 x 258.0 x 281.0mm (9-5/8inch x 10-1/8inch x 11-1/16inch) whereas 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).
KEF KUBE 12b is clearly the larger of the two speakers. Its body is 138mm wider, 165mm taller and 161mm deeper than KEF KC62.
Below you can see the front view size comparison of KEF KC62 and KEF KUBE 12b in scale.
Comparison image of KEF KC62 and KEF KUBE 12b 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 KC62 is approximately 725.0cm2 / 112.4inch2 and base area of the KEF KUBE 12b is approximately 1750.3cm2 / 271.3inch2. The KC62 requires 59% less surface area than the KUBE 12b 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 KC62 weighs 14.05kg / 30.9lbs and the KEF KUBE 12b weighs 20.68kg / 45.5lbs. This makes the KUBE 12b 47% heavier than the KC62.
Here is a comparison of how KC62 and KUBE 12b'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 KC62?
Here are the items that are included inside the box of KC62:
- 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 12b?
Here are the items that come with the KUBE 12b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
 Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
11 Hz
vs
22 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
140 Hz
|
Generates higher frequency |
 Height |
245mm
vs
410mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
725cm2
vs
1750cm2
|
Takes less floor space |
| Woofer Size |
12 inches
vs
6.5 inches
|
Larger woofer |
 Price per pair* |
900USD
vs
1500USD
|
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 141% more floor area. KEF KUBE 12b stands 161mm further into the room. KEF KUBE 12b is 165mm taller.
| General |
KEF KC62 |
KEF KUBE 12b |
| Brand |
KEF |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
1000 watts |
300 watts |
| Frequency Response |
11-200 Hz |
22-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
1000-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
2 |
1 |
| Woofer Size |
6.5" |
12" |
| Woofer Composition |
|
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
side |
front |
Physical Specs |
|
|
| Height |
245.0mm (9.6") |
410.0mm (16.1") |
| Width |
258.0mm (10.2") |
396.0mm (15.6") |
| Depth |
281.0mm (11.1") |
442.0mm (17.4") |
| Weight |
14.05kg (30.9lbs) |
20.68kg (45.5lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| 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 KC62 goes deeper - 11Hz against 22Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | KEF KC62 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 | B | KEF KUBE 12b moves more air: 12" against 2 x 6.5" is 1.7x the cone area, not the 1.31x 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. |
| Setup and tuning | evenly matched | The same tuning tools on both (room correction and onboard DSP). |
| Speaker-level inputs | A | KEF KC62 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. |
| Driver placement | depends | KEF KC62 fires side and KEF KUBE 12b fires front. A down-firing driver is more forgiving of a grille-less look and of a hard floor; a front-firing one is the safer choice on a thick carpet or a suspended timber floor. |
| Cabinet size | depends | KEF KC62 is about 75% 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 | KEF KUBE 12b costs less - $900 against $1,500, about 40% less. |
A KEF KC62 B KEF KUBE 12b
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 KC62 measures better, KEF KUBE 12b costs about 40% 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, KEF KC62 is the only one of these two you can connect at all. 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 $1,500 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.