In this review, we will be comparing Radius 200 and R400, two Passive Center Channel speakers from Monitor Audio and Polk Audio.
Let's have a brief look at the main features
of Monitor Audio Radius 200 and Polk R400 first before getting into our more
detailed comparison.
| Key Specs | Monitor Audio Radius 200 | Polk R400 |
|---|
| Brand | Monitor Audio
United Kingdom · founded 1972 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" gold dome C-CAM | 1" Pinnacle Ring Radiator |
|---|
| Woofer | 2 x 4" C-CAM | 2 x 6.5" Polypropylene Turbine Cone |
|---|
| Frequency response | 60-35k Hz | 48-39K Hz |
|---|
| Sensitivity | 86 dB | 89 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | 40-150 watts | 20-200 watts |
|---|
| Weight | 3.59kg / 7.9lbs | 14.91kg / 32.8lbs |
|---|
| Dimensions (H x W x D) | 4-15/16" x 13" x 6-3/8"
126.0 x 331.0 x 162.0mm | 7-13/16" x 24-5/16" x 14-5/8"
199.0 x 618.0 x 372.0mm |
|---|
What size room are the Monitor Audio Radius 200 and Polk R400 speakers good for?
The size of the room in which you are planning to use these loudspeakers is an important decision
factor. Here we have compared their suitability to various sizes of environments considering their size
and max power parameters:
| Listening Environment* |
Monitor Audio Radius 200 |
Polk R400 |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
Poor |
(* Approximate Room sizes: Small < 100sq. ft / 9 m2,
Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: >
400 sq. ft / 36 m2.
Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual
listening experience changes depending on floor height, room shape, surface materials, listening
position, speaker locations, etc.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Radius 200 and R400 are 2-way speakers.
Monitor Audio Radius 200Polk R400
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Monitor Audio Radius 200 |
Polk R400 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 4-inch
|
2 x 6.5-inch
|
Radius 200 features a 1" gold dome C-CAM Tweeter and 2 x 4" C-CAM Woofer. On the other hand, the R400 features a 1" Pinnacle Ring Radiator Tweeter and 2 x 6.5" Polypropylene Turbine Cone Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Radius 200 has a frequency range of 60-35k Hz whereas R400 has a frequency range of 48-39K Hz. With a minimum frequency of 48Hz, the R400 can go significantly deeper on the low side and provide stronger bass compared to the Radius 200's min frequency of 60Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Center Channel class in our database.
Low Frequency
Center Channel Speakers
Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
Radius 200 is a 6 ohms speaker compared to the R400 which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. Radius 200 sensitivity is rated at 86 dB and the R400's is rated at 89 dB. This 3 dB difference makes the Polk R400 a more sensitive speaker compared to Monitor Audio Radius 200, hence will play louder with the same amount of watts.
Sensitivity
Center Channel Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
R400 can handle a max power of 200 watts RMS, whereas Radius 200 has a max power handling value of 150 watts RMS, 50 watts less than the R400.
Note that higher power handling does not make a speaker louder: that depends mainly on
sensitivity and impedance. The calculator below shows how loud each of these actually plays
on a real amplifier.
Which plays louder on your amplifier?
Starting with a popular amplifier - change it to the one you own, or any you are
considering, and watch both numbers move.
Input Type and Bi-Amping / Bi-Wiring
Radius 200 features Binding post type posts and R400 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
Monitor Audio Radius 200's 5-Way post terminals
Polk R400's Binding post terminals
Polk R400 dual Port
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 Monitor Audio Radius 200's and Polk R400's external dimensions. Monitor Audio Radius 200 has external dimensions of 126.0 x 331.0 x 162.0mm (4-15/16 x 13 x 6-3/8inch) whereas Polk R400 has external dimensions of 199.0 x 618.0 x 372.0mm (7-13/16 x 24-5/16 x 14-5/8inch).
Polk R400 is clearly the larger of the two speakers. Its body is 287mm wider, 73mm taller and 210mm deeper than Monitor Audio Radius 200.
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 200 is approximately 536.2cm2 / 83.1inch2 and base area of the Polk R400 is approximately 2299.0cm2 / 356.3inch2. The Radius 200 requires 77% less surface area than the R400 which gives it a small advantage on placement in tight spaces.
Weight Comparison The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The Monitor Audio Radius 200 weighs 3.59kg / 7.9lbs and the Polk R400 weighs 14.91kg / 32.8lbs. This makes the R400 315% heavier than the Radius 200.
Here is a comparison of how Radius 200 and R400's weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
What's in the Box of Monitor Audio Radius 200?
Here are the items that are included inside the box of Radius 200:
- Center-channel loudspeaker
- Grille (installed)
- 4 Rubber feet
- Grille removal tool
- Owners Manual
- Important Safety Instructions
What's in the Box of Polk R400?
Here are the items that come with the R400:
- Center-channel loudspeaker
- Grille
- Owners Manual
- Online Registration
 Height |
126mm
vs
199mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
536cm2
vs
2299cm2
|
Takes less floor space |
 Price per pair* |
475USD
vs
649USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
200 watts
vs
150 watts
|
Handle more power from your amplifier |
 Sensitivity |
89 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 Woofer Size |
6.5 inches
vs
4 inches
|
Larger woofer |
|
Low Frequency Response |
48 Hz
vs
60 Hz
|
Generates deeper bass |
 High Frequency Response |
39k Hz
vs
35k Hz
|
Generates higher frequency |
| General |
Monitor Audio Radius 200 |
Polk Audio Reserve R400 |
| Brand |
Monitor Audio |
Polk Audio |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
40-150 watts |
20-200 watts |
| Sensitivity |
86 dB |
89 dB |
| Impedance |
6 ohms |
8 ohms |
| Impedance |
n/a |
4.1 ohms |
| Frequency Response |
60-35k Hz |
48-39K Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
4" |
6.5" |
| Woofer Composition |
C-CAM |
Polypropylene Turbine Cone |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
gold dome C-CAM |
Pinnacle Ring Radiator |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2500Hz |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
126.0mm (5") |
199.0mm (7.8") |
| Width |
331.0mm (13") |
618.0mm (24.3") |
| Depth |
162.0mm (6.4") |
372.0mm (14.6") |
| Weight |
3.59kg (7.9lbs) |
14.91kg (32.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
White |
Black, Walnut |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
A generation apart: Polk R400 is the newer design, against a 2016 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass | B | Polk R400 digs deeper - 48Hz against 60Hz. |
| Amplifier needs | B | Polk R400 is more sensitive (89dB vs 86dB), so it goes louder on the same amplifier. |
| Amplifier match | B | Polk R400 is the easier load at 8 ohms. |
| Headroom | B | Polk R400 takes more power (200W vs 150W) - more in hand in a big room. |
| Size | depends | Monitor Audio Radius 200 is easier to place; Polk R400 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Polk R400 sits in a wider range (10 models), so a matched surround system is easier later. |
| Price | A | Monitor Audio Radius 200 is cheaper - $475 against $649, about 27% less. |
A Monitor Audio Radius 200 B Polk R400
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 speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
The usual trade-off: Polk R400 measures better, Monitor Audio Radius 200 costs about about 37% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 60Hz anyway, which makes the cheaper Monitor Audio Radius 200 much easier to justify. In a large or open-plan room, Polk R400 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Monitor Audio Radius 200 is the easier speaker to get right.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.