In this review, we will be comparing KC62 and Radius 390, two Powered Subwoofer speakers from KEF and Monitor 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 KC62 and Monitor Audio Radius 390 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 KC62 and Monitor Audio Radius 390 have a totally different setup: the KEF KC62 features 2 x 6.5-inch drivers whereas the Radius 390 features 1 x 10-inch drivers.
Frequency Response
KC62 has a frequency range of 11-200 Hz whereas Radius 390 has a frequency range of 30-120 Hz. With a minimum frequency of 11Hz, the KC62 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 KEF KC62 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 Monitor Audio Radius 390 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 KC62's and Monitor Audio Radius 390's external dimensions. KEF KC62 has external dimensions of 245.0 x 258.0 x 281.0mm (9-5/8inch x 10-1/8inch x 11-1/16inch) whereas 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).
Monitor Audio Radius 390 is clearly the larger of the two speakers. Its body is 73mm wider, 103mm taller and 104mm deeper than KEF KC62.
Below you can see the front view size comparison of KEF KC62 and Monitor Audio Radius 390 in scale.
Comparison image of KEF KC62 and Monitor Audio Radius 390 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 KC62 is approximately 725.0cm2 / 112.4inch2 and base area of the Monitor Audio Radius 390 is approximately 1274.4cm2 / 197.5inch2. The KC62 requires 43% less surface area than the Radius 390 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 KC62 weighs 14.05kg / 30.9lbs and the Monitor Audio Radius 390 weighs 13.77kg / 30.3lbs. This makes the KC62 2% heavier than the Radius 390.
Here is a comparison of how KC62 and Radius 390'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 KC62?
Here are the items that are included inside the box of KC62:
- 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 Monitor Audio Radius 390?
Here are the items that come with the Radius 390:
- Powered sub
- 6-feet AC power cord
- 10.75-feet Mono minijack cable
- Owners Manual
- Important Safety Instructions
 Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
11 Hz
vs
30 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
245mm
vs
348mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
725cm2
vs
1274cm2
|
Takes less floor space |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| Woofer Size |
10 inches
vs
6.5 inches
|
Larger woofer |
 Price per pair* |
1150USD
vs
1500USD
|
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.
Monitor Audio Radius 390 needs about 76% more floor area. Monitor Audio Radius 390 stands 104mm further into the room. Monitor Audio Radius 390 is 103mm taller.
| General |
KEF KC62 |
Monitor Audio Radius 390 |
| Brand |
KEF |
Monitor Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
1000 watts |
220 watts |
| Frequency Response |
11-200 Hz |
30-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
1000-watt RMS |
220-watt RMS |
Drivers |
|
|
| Woofer Quantity |
2 |
1 |
| Woofer Size |
6.5" |
10" |
| Woofer Composition |
|
C-CAM |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
side |
side |
Physical Specs |
|
|
| Height |
245.0mm (9.6") |
348.0mm (13.7") |
| Width |
258.0mm (10.2") |
331.0mm (13") |
| Depth |
281.0mm (11.1") |
385.0mm (15.2") |
| Weight |
14.05kg (30.9lbs) |
13.77kg (30.3lbs) |
| Enclosure |
Acoustic Suspension |
Passive Radiator |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
2 Years |
| Labor Warranty |
2 Years |
2 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 | A | KEF KC62 goes deeper - 11Hz against 30Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | KEF KC62 has the bigger amplifier - 1000W against 220W RMS, about 6.6dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | evenly matched | Near-identical radiating area (2 x 6.5" against 10"). |
| Enclosure | depends | KEF KC62 is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; Monitor Audio Radius 390 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 KC62 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 KC62 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. |
| Cabinet size | depends | KEF KC62 is about 60% 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 | B | Monitor Audio Radius 390 costs less - $1,150 against $1,500, about 23% less. |
A KEF KC62 B Monitor Audio Radius 390
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?
KEF KC62 leads across most of the measured areas for a modest premium, so it is the easier pick if the budget stretches. Monitor Audio Radius 390 is the one to take if it does not. Films or music? If this is mainly a home cinema, Monitor Audio Radius 390 will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KC62 is usually the easier one to make sound right. Check your amplifier first: if it has no subwoofer or preamp output, KEF KC62 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.