In this review, we will be comparing R400 and Q250c, two Passive Center Channel speakers from Polk Audio and KEF. Let's have a brief look at the main features
of Polk R400 and KEF Q250c first before getting into our more
detailed comparison.
What size room are the Polk R400 and KEF Q250c 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 Polk R400 and KEF Q250c 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 R400 and Q250c are 2-way speakers.
Driver |
Polk R400 |
KEF Q250c |
Driver Setup
|
2-way
|
2-way
|
Tweeter
|
1-inch
|
1-inch
|
Midrange
|
- |
- |
Woofer
|
2 x 6.5-inch
|
1 x 5.25-inch
|
R400 features a 1" Pinnacle Ring Radiator Tweeter and 2 x 6.5" Polypropylene Turbine Cone Woofer with a Crossover frequency at 2500Hz. On the other hand, the Q250c features a 1" vented aluminum Dome Tweeter and 1 x 5.25" aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
R400 has a frequency range of 48-39K Hz whereas Q250c has a frequency range of 68-28k Hz. With a minimum frequency of 48Hz, the R400 can go significantly deeper on the low side and provide stronger bass compared to the Q250c's min frequency of 68Hz.
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
R400 and Q250c have the same Impedance of 8 ohms but where they differ is the sensitivity levels. R400 sensitivity is rated at 89 dB and the Q250c's is at 87 dB. This 2 dB difference makes the Polk R400 a more sensitive speaker compared to KEF Q250c, 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.
R400 can handle a max power of 200 watts RMS from the amp the whereas Q250c 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
R400 features Binding post type posts and Q250c has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
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 Polk R400's and KEF Q250c's external dimensions. 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) whereas KEF Q250c has external dimensions of 181.0 x 526.0 x 216.0mm ( 7-1/8 x 20-11/16 x 8-1/2inch) .
Polk R400 is clearly the larger of the two speakers. Its body is 92mm wider, 18mm taller and 156mm deeper than KEF Q250c.
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 Polk R400 is approximately 2299.0cm2 / 356.3inch2 and base area of the KEF Q250c is approximately 1136.2cm2 / 176.1inch2. The R400 requires 102% more surface area than the Q250c which gives it a small disadvantage 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 Polk R400 weighs 14.91kg / 32.8lbs and the KEF Q250c weighs 7.50kg / 16.5lbs. This makes the R400 99% heavier than the Q250c.
Here is a comparison of how R400 and Q250c'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 Polk R400?
Here are the items that are included inside the box of R400:
Center-channel loudspeakerGrilleOwners ManualOnline Registration
What's in the Box of KEF Q250c?
Here are the items that come with the Q250c:
Center-channel loudspeaker 4 Self-adhesive rubber feet Owners Manual Warranty Information
Max Input Power |
200 watts
vs
100 watts
|
Handle more power from your amplifier |
Sensitivity |
89 dB
vs
87 dB
|
Play louder with same amount of amplification power |
Minimum Impedance |
4.1 ohms
vs
3.4 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
68 Hz
|
Generates deeper bass |
High Frequency Response |
39k Hz
vs
28k Hz
|
Generates higher frequency |
Passive Radiator |
one 6.5-inch
vs
None
|
Increases the bass performance |
Height |
181mm
vs
199mm
|
Easier to fit in smaller spaces |
Base Surface Area |
1136cm2 (526x216mm)
vs
2299cm2 (618x372mm)
|
Takes less floor space |
Price per pair* |
600USD
vs
649USD
|
costs less (*prices may change depending on the seller, location and time) |
General |
Polk Audio Reserve R400 |
KEF Q250c |
Brand |
Polk Audio |
KEF |
Speaker Type |
Center channel speaker |
Center channel speaker |
Power Range |
20-200 watts |
10-100 watts |
Sensitivity |
89 dB |
87 dB |
Impedance |
8 ohms |
8 ohms |
Impedance |
4.1 ohms |
3.4 ohms |
Frequency Response |
48-39K Hz |
68-28k Hz |
Drivers |
|
|
Woofer Quantity |
2 |
1 |
Woofer Size |
6.5" |
5.25" |
Woofer Composition |
Polypropylene Turbine Cone |
aluminum |
Woofer Surround Material |
Rubber |
Rubber |
Tweeter Size |
1" |
1" |
Tweeter Type |
Pinnacle Ring Radiator |
Dome |
Aimable Tweeter |
No |
No |
Midrange Driver |
N/A" |
No |
Crossover Frequency |
2500Hz |
2500Hz |
Firing Direction |
rear |
n/a |
Physical Specs |
|
|
Height |
199.0mm (7.8") |
181.0mm (7.1") |
Width |
618.0mm (24.3") |
526.0mm (20.7") |
Depth |
372.0mm (14.6") |
216.0mm (8.5") |
Weight |
14.91kg (32.8lbs) |
7.50kg (16.5lbs) |
Enclosure |
Bass Reflex |
Passive Radiator |
Available Colors |
Black, Walnut |
Satin White, Satin Black, Walnut |
Grille |
Yes |
optional |
Moisture Resistancy |
No |
No |
Connections |
|
|
Biamp Inputs |
No |
n/a |
Other |
|
|
Parts Warranty |
5 Years |
5 Years |
Labor Warranty |
5 Years |
5 Years |