In this review, we will be comparing Kube 8 MIE and Kube 15 MIE, 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 Kube 8 MIE and KEF Kube 15 MIE 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 8 MIEand KEF Kube 15 MIE have a single woofer setup however the KEF Kube 8 MIE's woofer is 8-inch whereas the KEF Kube 15 MIE features a 15-inch woofer.
Frequency Response
Kube 8 MIE has a frequency range of 34-140 Hz whereas Kube 15 MIE has a frequency range of 20-140 Hz. With a minimum frequency of 20Hz, the Kube 15 MIE can go significantly deeper on the low side and provide stronger bass compared to the Kube 8 MIE'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 8 MIE and KEF Kube 15 MIE 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 8 MIE's and KEF Kube 15 MIE's external dimensions. KEF Kube 8 MIE has external dimensions of 293 x 293 x 310 mm (11.5 x 11.5 x 12.2 in) whereas KEF Kube 15 MIE has external dimensions of 519 x 500 x 515 mm (20.4 x 19.7 x 20.3 in).
KEF Kube 15 MIE is clearly the larger of the two speakers. Its body is 207mm wider, 226mm taller and 205mm deeper than KEF Kube 8 MIE.
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 8 MIE is approximately 908.3cm2 / 140.8inch2 and base area of the KEF Kube 15 MIE is approximately 2575.0cm2 / 399.1inch2. The Kube 8 MIE requires 65% less surface area than the Kube 15 MIE 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 8 MIE weighs 9.40kg / 20.7lbs and the KEF Kube 15 MIE weighs 27.50kg / 60.5lbs. This makes the Kube 15 MIE 193% heavier than the Kube 8 MIE.
Here is a comparison of how Kube 8 MIE and Kube 15 MIE'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 8 MIE?
Here are the items that are included inside the box of Kube 8 MIE:
- Kube 8 MIE subwoofer
- Power cord
- Euroblock speaker level connector
- User manual and warranty information
What's in the Box of KEF Kube 15 MIE?
Here are the items that come with the Kube 15 MIE:
- Kube 15 MIE subwoofer
- Power cord
- Euroblock speaker level connector
- User manual and warranty information
 Height |
293mm
vs
519mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
908cm2
vs
2575cm2
|
Takes less floor space |
 Price per pair* |
700USD
vs
1399USD
|
costs less (*prices may change depending on the seller, location and time) |
 Woofer Size |
15 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
20 Hz
vs
34 Hz
|
Generates deeper bass |
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 15 MIE needs about 183% more floor area. KEF Kube 15 MIE stands 205mm further into the room. KEF Kube 15 MIE is 226mm taller.
| General |
KEF Kube 8 MIE |
KEF Kube 15 MIE |
| Brand |
KEF |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
300 watts |
| Frequency Response |
34-140 Hz |
20-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
15" |
| Woofer Composition |
Polypropylene |
Polypropylene |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
40-140 Hz |
Physical Specs |
|
|
| Height |
293.0mm (11.5") |
519.0mm (20.4") |
| Width |
293.0mm (11.5") |
500.0mm (19.7") |
| Depth |
310.0mm (12.2") |
515.0mm (20.3") |
| Weight |
9.40kg (20.7lbs) |
27.50kg (60.5lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
2 Years |
| Labor Warranty |
2 Years |
2 Years |
Siblings in KEF's KUBE MIE range - same design thinking, different size. It comes down to your room and your budget.
| Area | Better | Why |
|---|
| Bass depth | B | KEF Kube 15 MIE goes deeper - 20Hz against 34Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | evenly matched | Much the same amplifier (300W vs 300W RMS) - under 1dB apart. |
| Driver area | B | KEF Kube 15 MIE moves more air: 15" against 8" is 3.52x the cone area, not the 1.88x 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). |
| Cabinet size | depends | KEF Kube 8 MIE is about 80% 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 8 MIE costs less - $700 against $1,399, about 50% less. |
A KEF Kube 8 MIE B KEF Kube 15 MIE
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 15 MIE measures better, KEF Kube 8 MIE costs about 50% 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 $700 each, two KEF Kube 8 MIE cost about $1,400 against $1,399 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 8 MIE 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.