In this review, we will be comparing KUBE 8b and Minx X301, two Powered Subwoofer speakers from KEF and Cambridge Audio. 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 Cambridge Audio Minx X301 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 KUBE 8band Cambridge Audio Minx X301 have the same driver set up: Both subwoofers have 1 x 8" drivers.
Frequency Response
KUBE 8b has a frequency range of 34-140 Hz whereas Minx X301 has a frequency range of 31-200 Hz. With a minimum frequency of 31Hz, the Minx X301 can go slightly deeper then 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
Cambridge Audio Minx X301
High Frequency
Subwoofer Speakers
Cambridge Audio Minx X301
Cabinet Type
The KEF KUBE 8b 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 Cambridge Audio Minx X301 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 8b's and Cambridge Audio Minx X301'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 Cambridge Audio Minx X301 has external dimensions of 312.0 x 267.0 x 310.0mm (12-1/4 x 10-1/2 x 12-3/16inch).
Cambridge Audio Minx X301 is 29mm narrower and 29mm less deeper than KEF KUBE 8b but it is also 18mm taller.
Below you can see the front view size comparison of KEF KUBE 8b and Cambridge Audio Minx X301 in scale.
Comparison image of KEF KUBE 8b and Cambridge Audio Minx X301 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 8b is approximately 1003.4cm2 / 155.5inch2 and base area of the Cambridge Audio Minx X301 is approximately 827.7cm2 / 128.3inch2. The KUBE 8b requires 21% more surface area than the Minx X301 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 8b weighs 11.36kg / 25lbs and the Cambridge Audio Minx X301 weighs 7.50kg / 16.5lbs. This makes the KUBE 8b 51% heavier than the Minx X301.
Here is a comparison of how KUBE 8b and Minx X301's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
Cambridge Audio Minx X301
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 Cambridge Audio Minx X301?
Here are the items that come with the Minx X301:
- Powered subwoofer
- Grille (installed)
- 6-feet AC power cord
- Installation Guide
- Important Safety Instructions
 Height |
294mm
vs
312mm
|
Easier to fit in smaller spaces |
 Low Frequency Response |
31 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
140 Hz
|
Generates higher frequency |
 Base Surface Area |
827cm2
vs
1003cm2
|
Takes less floor space |
 Price per pair* |
549USD
vs
600USD
|
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 8b needs about 21% more floor area. KEF KUBE 8b stands 29mm further into the room. Cambridge Audio Minx X301 is 18mm taller.
| General |
KEF KUBE 8b |
Cambridge Audio Minx X301 |
| Brand |
KEF |
Cambridge Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
300 watts |
| Frequency Response |
34-140 Hz |
31-200 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
8" |
| Woofer Composition |
|
Aluminum |
| 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") |
312.0mm (12.3") |
| Width |
296.0mm (11.7") |
267.0mm (10.5") |
| Depth |
339.0mm (13.3") |
310.0mm (12.2") |
| Weight |
11.36kg (25lbs) |
7.50kg (16.5lbs) |
| Enclosure |
Acoustic Suspension |
Passive Radiator |
| Grille |
n/a |
Yes |
| 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 | Cambridge Audio Minx X301 goes deeper - 31Hz against 34Hz. A real difference, though most music has little content below 34Hz. |
| Amplifier power | evenly matched | Much the same amplifier (300W vs 300W RMS) - under 1dB apart. |
| Driver area | evenly matched | Near-identical radiating area (8" against 8"). |
| Enclosure | depends | KEF KUBE 8b is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; Cambridge Audio Minx X301 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. |
| Warranty | B | Cambridge Audio Minx X301 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 | Cambridge Audio Minx X301 costs less - $549 against $600, about 9% less. |
A KEF KUBE 8b B Cambridge Audio Minx X301
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?
Cambridge Audio Minx X301 has the edge on paper, though not by much. The "depends" rows are more likely to decide this than the score is. Films or music? If this is mainly a home cinema, Cambridge Audio Minx X301 will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KUBE 8b is usually the easier one to make sound right.
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.