In this review, we will be comparing KUBE 8b and Sub 1000 F, two Powered Subwoofer speakers from KEF and Focal. 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 8b and Focal Sub 1000 F 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 8band Focal Sub 1000 F have a single woofer setup however the KEF KUBE 8b's woofer is 8-inch whereas the Focal Sub 1000 F features a 12-inch woofer.
Frequency Response
KUBE 8b has a frequency range of 34-140 Hz whereas Sub 1000 F has a frequency range of 24-200 Hz. With a minimum frequency of 24Hz, the Sub 1000 F 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 8b and Focal Sub 1000 F 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 8b's and Focal Sub 1000 F's external dimensions. 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) whereas Focal Sub 1000 F has external dimensions of 421.0 x 401.0 x 474.0mm (16-9/16 x 15-3/4 x 18-5/8inch).
Focal Sub 1000 F is clearly the larger of the two speakers. Its body is 105mm wider, 127mm taller and 135mm deeper than KEF KUBE 8b.
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 8b is approximately 1003.4cm2 / 155.5inch2 and base area of the Focal Sub 1000 F is approximately 1900.7cm2 / 294.6inch2. The KUBE 8b requires 47% less surface area than the Sub 1000 F 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 KUBE 8b weighs 11.36kg / 25lbs and the Focal Sub 1000 F weighs 21.36kg / 47lbs. This makes the Sub 1000 F 88% heavier than the KUBE 8b.
Here is a comparison of how KUBE 8b and Sub 1000 F'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 8b?
Here are the items that are included inside the box of KUBE 8b:
- 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 Focal Sub 1000 F?
Here are the items that come with the Sub 1000 F:
- Powered subwoofer
- 8-feet AC power cord
- Grille
- User Manual
 Height |
294mm
vs
421mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
1900cm2
|
Takes less floor space |
 Price per pair* |
600USD
vs
2099USD
|
costs less (*prices may change depending on the seller, location and time) |
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
140 Hz
|
Generates higher frequency |
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.
Focal Sub 1000 F needs about 89% more floor area. Focal Sub 1000 F stands 135mm further into the room. Focal Sub 1000 F is 127mm taller.
| General |
KEF KUBE 8b |
Focal Sub 1000 F |
| Brand |
KEF |
Focal |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
1000 watts |
| Frequency Response |
34-140 Hz |
24-200 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
1000-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
12" |
| Woofer Composition |
|
Flax |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
n/a |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
294.0mm (11.6") |
421.0mm (16.6") |
| Width |
296.0mm (11.7") |
401.0mm (15.8") |
| Depth |
339.0mm (13.3") |
474.0mm (18.7") |
| Weight |
11.36kg (25lbs) |
21.36kg (47lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
3 Years |
| Labor Warranty |
2 Years |
3 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 | B | Focal Sub 1000 F goes deeper - 24Hz against 34Hz. That gap covers the lowest notes of a five-string bass and a concert bass drum. |
| Amplifier power | B | Focal Sub 1000 F 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 | Focal Sub 1000 F 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. |
| Cabinet size | depends | KEF KUBE 8b is about 63% 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 | Focal Sub 1000 F 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 | A | KEF KUBE 8b costs less - $600 against $2,099, about 71% less. |
A KEF KUBE 8b B Focal Sub 1000 F
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: Focal Sub 1000 F measures better, KEF KUBE 8b costs about 71% less. In a normal room, placement will make a bigger difference than the gap between these two. 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 $600 each, two KEF KUBE 8b cost about $1,200 against $2,099 for one of the other, which is worth a thought. If placement is the constraint - a corner, behind a sofa, under a desk - KEF KUBE 8b 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.