In this review, we will be comparing Kube 15 MIE and ForceField 40, two Powered Subwoofer speakers from KEF and GoldenEar. 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 15 MIE and GoldenEar ForceField 40 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 15 MIEand GoldenEar ForceField 40 have a single woofer setup however the KEF Kube 15 MIE's woofer is 15-inch whereas the GoldenEar ForceField 40 features a 10-inch woofer.
Frequency Response
Kube 15 MIE has a frequency range of 20-140 Hz whereas ForceField 40 has a frequency range of 14-250 Hz. With a minimum frequency of 14Hz, the ForceField 40 can go significantly deeper on the low side and provide stronger bass compared to the Kube 15 MIE's min frequency of 20Hz.
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
The KEF Kube 15 MIE has a Acoustic Suspension type cabinet. 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. On the other hand the GoldenEar ForceField 40 have Passive Radiator type enclosure. Passive Radiator type subwoofers sports a non-powered cone that moves in response to the main woofer to move air out in order to generate stronger bass in a smaller body compared to ported or sealed 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 15 MIE's and GoldenEar ForceField 40's external dimensions. KEF Kube 15 MIE has external dimensions of 519 x 500 x 515 mm (20.4 x 19.7 x 20.3 in) whereas GoldenEar ForceField 40 has external dimensions of 378.0 x 339.0 x 485.0mm (14-7/8inch x 13-5/16inch x 19-1/16inch).
KEF Kube 15 MIE is clearly the larger of the two speakers. Its body is 161mm wider, 141mm taller and 30mm deeper than GoldenEar ForceField 40.
Size, drawn to scale
Both speakers 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 surface and pushed back to the same wall, so the deeper one visibly sticks out further.
KEF Kube 15 MIE needs about 57% more floor or shelf area. KEF Kube 15 MIE is 30mm deeper, so it stands that much further out from the wall. KEF Kube 15 MIE is 141mm taller.
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 15 MIE is approximately 2575.0cm2 / 399.1inch2 and base area of the GoldenEar ForceField 40 is approximately 1644.2cm2 / 254.9inch2. The Kube 15 MIE requires 57% more surface area than the ForceField 40 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 15 MIE weighs 27.50kg / 60.5lbs and the GoldenEar ForceField 40 weighs 18.41kg / 40.5lbs. This makes the Kube 15 MIE 49% heavier than the ForceField 40.
Here is a comparison of how Kube 15 MIE and ForceField 40'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 15 MIE?
Here are the items that are included inside the box of Kube 15 MIE:
- Kube 15 MIE subwoofer
- Power cord
- Euroblock speaker level connector
- User manual and warranty information
What's in the Box of GoldenEar ForceField 40?
Here are the items that come with the ForceField 40:
- Powered subwoofer
- 10-feet AC power cord
- Quick Start Guide
- Owners Manual
 Woofer Size |
15 inches
vs
10 inches
|
Larger woofer |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| Low Frequency Response |
14 Hz
vs
20 Hz
|
Generates deeper bass |
 High Frequency Response |
250 Hz
vs
140 Hz
|
Generates higher frequency |
 Height |
378mm
vs
519mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1644cm2
vs
2575cm2
|
Takes less floor space |
 Price per pair* |
1199USD
vs
1399USD
|
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 15 MIE needs about 57% more floor area. KEF Kube 15 MIE stands 30mm further into the room. KEF Kube 15 MIE is 141mm taller.
| General |
KEF Kube 15 MIE |
GoldenEar ForceField 40 |
| Brand |
KEF |
GoldenEar |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
1000 watts |
| Frequency Response |
20-140 Hz |
14-250 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
1000-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
15" |
10" |
| Woofer Composition |
Polypropylene |
Polypropylene |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
n/a |
| Firing Direction |
n/a |
front and bottom |
Physical Specs |
|
|
| Height |
519.0mm (20.4") |
378.0mm (14.9") |
| Width |
500.0mm (19.7") |
339.0mm (13.3") |
| Depth |
515.0mm (20.3") |
485.0mm (19.1") |
| Weight |
27.50kg (60.5lbs) |
18.41kg (40.5lbs) |
| Enclosure |
Acoustic Suspension |
Passive Radiator |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
3 Years |
| Labor Warranty |
2 Years |
3 Years |
A sealed subwoofer against a passive radiator one. That is the most consequential line on this page: it decides how the bass rolls off, how it behaves in a small room, and how much output you get for the size of the box.
| Area | Better | Why |
|---|
| Bass depth | B | GoldenEar ForceField 40 goes deeper - 14Hz against 20Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | B | GoldenEar ForceField 40 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 15 MIE moves more air: 15" against 10" 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 | depends | KEF Kube 15 MIE is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; GoldenEar ForceField 40 is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Speaker-level inputs | A | KEF Kube 15 MIE 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 15 MIE 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. |
| Phase control | A | KEF Kube 15 MIE has a phase control. Without one, the only way to fix a cancellation at the crossover is to move the box. |
| Cabinet size | depends | GoldenEar ForceField 40 is about 53% 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 | GoldenEar ForceField 40 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 | B | GoldenEar ForceField 40 costs less - $1,199 against $1,399, about 14% less. |
A KEF Kube 15 MIE B GoldenEar ForceField 40
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?
Neither runs away with it - they trade advantages. Let your room size and where the box can actually stand settle it. Films or music? If this is mainly a home cinema, GoldenEar ForceField 40 will hit harder for the money; if it is mainly for music in a normal-sized room, KEF Kube 15 MIE is usually the easier one to make sound right. Check your amplifier first: if it has no subwoofer or preamp output, KEF Kube 15 MIE is the only one of these two you can connect at all.
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.