In this review, we will be comparing MSX Sub 300 and KUBE 10b, two Powered Subwoofer speakers from Cambridge Audio and 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 Cambridge Audio MSX Sub 300 and KEF KUBE 10b 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 Cambridge Audio MSX Sub 300and KEF KUBE 10b have a single woofer setup however the Cambridge Audio MSX Sub 300's woofer is 8-inch whereas the KEF KUBE 10b features a 10-inch woofer.
Frequency Response
MSX Sub 300 has a frequency range of 31-200 Hz whereas KUBE 10b has a frequency range of 24-140 Hz. With a minimum frequency of 24Hz, the KUBE 10b can go significantly deeper on the low side and provide stronger bass compared to the MSX Sub 300's min frequency of 31Hz.
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 MSX Sub 300
High Frequency
Subwoofer Speakers
Cambridge Audio MSX Sub 300
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 Cambridge Audio MSX Sub 300's and KEF KUBE 10b's external dimensions. Cambridge Audio MSX Sub 300 has external dimensions of 312.7 x 266.7 x 311.2mm () whereas KEF KUBE 10b has external dimensions of 372.0 x 356.0 x 397.0mm (14-5/8 x 14 x 15-5/8inch).
KEF KUBE 10b is clearly the larger of the two speakers. Its body is 89.3mm wider, 59.3mm taller and 85.8mm deeper than Cambridge Audio MSX Sub 300.
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 10b needs about 70% more floor or shelf area. KEF KUBE 10b is 86mm deeper, so it stands that much further out from the wall. KEF KUBE 10b is 59mm 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 Cambridge Audio MSX Sub 300 is approximately 830.0cm2 / 128.7inch2 and base area of the KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The MSX Sub 300 requires 41% less surface area than the KUBE 10b 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 Cambridge Audio MSX Sub 300 weighs 7.48kg / 16.5lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the KUBE 10b 134% heavier than the MSX Sub 300.
Here is a comparison of how MSX Sub 300 and KUBE 10b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
Cambridge Audio MSX Sub 300
 High Frequency Response |
200 Hz
vs
140 Hz
|
Generates higher frequency |
 Height |
312mm
vs
372mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
830cm2
vs
1413cm2
|
Takes less floor space |
 Price per pair* |
549USD
vs
750USD
|
costs less (*prices may change depending on the seller, location and time) |
 Woofer Size |
10 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
31 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 10b needs about 70% more floor area. KEF KUBE 10b stands 86mm further into the room. KEF KUBE 10b is 59mm taller.
| General |
Cambridge Audio MSX Sub 300 |
KEF KUBE 10b |
| Brand |
Cambridge Audio |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Frequency Response |
31-200 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
10" |
| Woofer Composition |
|
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
312.7mm (12.3") |
372.0mm (14.6") |
| Width |
266.7mm (10.5") |
356.0mm (14") |
| Depth |
311.2mm (12.3") |
397.0mm (15.6") |
| Weight |
7.48kg (16.5lbs) |
17.50kg (38.5lbs) |
| Enclosure |
|
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
2 Years |
| Labor Warranty |
2 Years |
2 Years |
A passive radiator subwoofer against a sealed 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 | KEF KUBE 10b goes deeper - 24Hz against 31Hz. That gap covers the lowest notes of a five-string bass and a concert bass drum. |
| Amplifier power | evenly matched | Much the same amplifier (300W vs 300W RMS) - under 1dB apart. |
| Driver area | B | KEF KUBE 10b moves more air: 10" against 8" is 1.56x the cone area, not the 1.25x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | Cambridge Audio MSX Sub 300 is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet; KEF KUBE 10b is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Cabinet size | depends | Cambridge Audio MSX Sub 300 is about 51% 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 | Cambridge Audio MSX Sub 300 costs less - $549 against $750, about 27% less. |
A Cambridge Audio MSX Sub 300 B KEF KUBE 10b
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 10b measures better, Cambridge Audio MSX Sub 300 costs about 27% less. In a normal room, placement will make a bigger difference than the gap between these two. Films or music? If this is mainly a home cinema, Cambridge Audio MSX Sub 300 will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KUBE 10b is usually the easier one to make sound right. If placement is the constraint - a corner, behind a sofa, under a desk - Cambridge Audio MSX Sub 300 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.