In this review, we will be comparing Radius 390 and KUBE 10b, two Powered Subwoofer speakers from Monitor 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 Monitor Audio Radius 390 and KEF KUBE 10b first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the Monitor Audio Radius 390 and KEF KUBE 10b compare and hopefully end up with enough arguments to decide which one of these subwoofers is the better choice for you.
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Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Monitor Audio Radius 390and KEF KUBE 10b have the same driver set up: Both subwoofers have 1 x 10" drivers.
Frequency Response
Radius 390 has a frequency range of 30-120 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 Radius 390's min frequency of 30Hz.
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 Monitor Audio Radius 390 has a Passive Radiator type cabinet. 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. On the other hand the KEF KUBE 10b have Acoustic Suspension type enclosure. 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
Size of a speaker can sometimes become an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare Monitor Audio Radius 390's and KEF KUBE 10b's external dimensions. Monitor Audio Radius 390 has external dimensions of 348.0 x 331.0 x 385.0mm ( 13-11/16 x 13 x 15-1/8inch) 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 25mm wider, 24mm taller and 12mm deeper than Monitor Audio Radius 390.
Below you can see the front view size comparison of Monitor Audio Radius 390 and KEF KUBE 10b in scale.
Comparison image of Monitor Audio Radius 390 and KEF KUBE 10b 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 Monitor Audio Radius 390 is approximately 1274.4cm2 / 197.5inch2 and base area of the KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The Radius 390 requires 10% 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 Monitor Audio Radius 390 weighs 13.77kg / 30.3lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the KUBE 10b 27% heavier than the Radius 390.
Here is a comparison of how Radius 390 and KUBE 10b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of Monitor Audio Radius 390?
Here are the items that are included inside the box of Radius 390:
Powered sub6-feet AC power cord10.75-feet Mono minijack cableOwners ManualImportant Safety Instructions
What's in the Box of KEF KUBE 10b?
Here are the items that come with the KUBE 10b:
Powered subwoofer6.5-feet AC power cordSpeaker-level input blockUser ManualImportant Safety InformationWarranty Information
 Height |
348mm
vs
372mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1274cm2 (331x385mm)
vs
1413cm2 (356x397mm)
|
Takes less floor space |
 Low Frequency Response |
24 Hz
vs
30 Hz
|
Generates deeper bass |
 High Frequency Response |
140k Hz
vs
120k Hz
|
Generates higher frequency |
 Price per pair* |
750USD
vs
1150USD
|
costs less (*prices may change depending on the seller, location and time) |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| General |
Monitor Audio Radius 390 |
KEF KUBE 10b |
| Brand |
Monitor Audio |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
220 watts |
300 watts |
| Frequency Response |
30-120 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
220-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
10" |
| Woofer Composition |
C-CAM |
Not given |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
side |
front |
Physical Specs |
|
|
| Height |
348.0mm (13.7") |
372.0mm (14.6") |
| Width |
331.0mm (13") |
356.0mm (14") |
| Depth |
385.0mm (15.2") |
397.0mm (15.6") |
| Weight |
13.77kg (30.3lbs) |
17.50kg (38.5lbs) |
| Enclosure |
Passive Radiator |
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
2 Years |
| Labor Warranty |
2 Years |
2 Years |