In this review, we will be comparing LS50C Meta and R400, two Passive Center Channel speakers from KEF and Polk Audio. Let's have a brief look at the main features
of KEF LS50C Meta and Polk R400 first before getting into our more
detailed comparison.
What size room are the KEF LS50C Meta 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:
In the following sections, we will get into more detail in order to better understand how the KEF LS50C Meta and Polk R400 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
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Drivers
Both LS50C Meta and R400 are 2-way speakers.
| Driver |
KEF LS50C Meta |
Polk R400 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
2 x 6.5-inch
|
LS50C Meta features a 1" Aluminum Vented dome Tweeter and 1 x 5.25" aluminum Woofer with a Crossover frequency at 2100Hz. 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
LS50C Meta has a frequency range of 79-28k 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 LS50C Meta's min frequency of 79Hz.
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 Center Channel class in our database.
Low Frequency
Center Channel Speakers
High Frequency
Center Channel Speakers
None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
LS50C Meta and R400 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. LS50C Meta sensitivity is rated at 85 dB and the R400's is at 89 dB. This 4 dB difference makes the Polk R400 a more sensitive speaker compared to KEF LS50C Meta, 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. While using an amplifier within this range ensures the nominal performance , inputting a power that is higher than the max wattage can result in a damaged speaker.
LS50C Meta can handle a max power of 200 watts RMS from the amp the whereas LS50C Meta has a max power handling value of 100 watts RMS , 100 watts less than the R400.
Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker
compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters
such as Impedance, sensitivity and system efficiencies.
Input Type and Bi-Amping / Bi-Wiring
LS50C Meta features Binding post type posts and R400 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
KEF LS50C Meta's Binding post terminals
Polk R400's Binding post terminals
Cabinet Type and Port Position
Both LS50C Meta and R400 have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.
If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.
KEF LS50C Meta off-set flexible Port
Polk R400 dual Port
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 KEF LS50C Meta's and Polk R400's external dimensions. KEF LS50C Meta has external dimensions of 301.0 x 201.0 x 281.0mm ( 11-13/16 x 7-7/8 x 11-1/16inch) 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) .
KEF LS50C Meta is 417mm narrower and 91mm less deeper than Polk R400 but it is also 102mm 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 KEF LS50C Meta is approximately 564.8cm2 / 87.5inch2 and base area of the Polk R400 is approximately 2299.0cm2 / 356.3inch2. The LS50C Meta requires 75% 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 KEF LS50C Meta weighs 7.82kg / 17.2lbs and the Polk R400 weighs 14.91kg / 32.8lbs. This makes the R400 91% heavier than the LS50C Meta.
Here is a comparison of how LS50C Meta 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 KEF LS50C Meta?
Here are the items that are included inside the box of LS50C Meta:
Center-channel loudspeakerFoam port plug4 Self-adhesive rubber feetOwners ManualWarranty Registration Card
What's in the Box of Polk R400?
Here are the items that come with the R400:
Center-channel loudspeakerGrilleOwners ManualOnline Registration
 Base Surface Area |
564cm2 (201x281mm)
vs
2299cm2 (618x372mm)
|
Takes less floor space |
 Max Input Power |
200 watts
vs
100 watts
|
Handle more power from your amplifier |
 Sensitivity |
89 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 Minimum Impedance |
4.1 ohms
vs
3.5 ohms
|
Very low impedance levels puts more pressure on amplifier |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
| Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
48 Hz
vs
79 Hz
|
Generates deeper bass |
 High Frequency Response |
39k Hz
vs
28k Hz
|
Generates higher frequency |
 Height |
199mm
vs
301mm
|
Easier to fit in smaller spaces |
 Price per pair* |
649USD
vs
900USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF LS50C Meta |
Polk Audio Reserve R400 |
| Brand |
KEF |
Polk Audio |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
40-100 watts |
20-200 watts |
| Sensitivity |
85 dB |
89 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.5 ohms |
4.1 ohms |
| Frequency Response |
79-28k Hz |
48-39K Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
5.25" |
6.5" |
| Woofer Composition |
aluminum |
Polypropylene Turbine Cone |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Vented dome |
Pinnacle Ring Radiator |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
N/A" |
| Crossover Frequency |
2100Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
301.0mm (11.9") |
199.0mm (7.8") |
| Width |
201.0mm (7.9") |
618.0mm (24.3") |
| Depth |
281.0mm (11.1") |
372.0mm (14.6") |
| Weight |
7.82kg (17.2lbs) |
14.91kg (32.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
Grey |
Black, Walnut |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |