In this review, we will be comparing Q550 and S55, two Passive Floor-standing speakers from KEF and Polk Audio. Let's have a brief look at the main features
of KEF Q550 and Polk S55 first before getting into our more
detailed comparison.
What size room are the KEF Q550 and Polk S55 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 Q550 and Polk S55 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 Q550 and S55 are 2-way speakers.
Driver |
KEF Q550 |
Polk S55 |
Driver Setup
|
2-way
|
2-way
|
Tweeter
|
1-inch
|
1-inch
|
Midrange
|
- |
- |
Woofer
|
2 x 5.25-inch
|
2 x 6.5-inch
|
Q550 features a 1" vented aluminum Dome Tweeter and 2 x 5.25" Aluminum Woofer with a Crossover frequency at 2500Hz. On the other hand, the S55 features a 1" Terylene Dome Tweeter and 2 x 6.5" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Q550 has a frequency range of 58-28k Hz whereas S55 has a frequency range of 32-40k Hz. With a minimum frequency of 32Hz, the S55 can go significantly deeper on the low side and provide stronger bass compared to the Q550's min frequency of 58Hz.
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 Floor-standing class in our database.
Low Frequency
Floor-standing Speakers
High Frequency
Floor-standing 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
Q550 and S55 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Q550 sensitivity is rated at 87 dB and the S55's is at 90 dB. This 3 dB difference makes the Polk S55 a more sensitive speaker compared to KEF Q550, hence will play louder with the same amount of watts.
Sensitivity
Floor-standing 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.
Q550 can handle a max power of 200 watts RMS from the amp the whereas Q550 has a max power handling value of 130 watts RMS , 70 watts less than the S55.
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
S55 features 5-way post posts which make bi-amping or bi-wiring possible. Q550 has a Binding post which doesn't feature bi-amping/bi-wiring.
Cabinet Type and Port Position
Q550 has a front firing port whereas S55 has a bottom firing ports. KEF Q550's front-firing port gives more flexibility in placement in regards to proximity to walls compared to Polk S55 with its rear-firing 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 Q550's and Polk S55's external dimensions. KEF Q550 has external dimensions of 894.0 x 296.0 x 313.0mm ( 35-3/16 x 11-5/8 x 12-5/16inch) whereas Polk S55 has external dimensions of 1056.0 x 299.0 x 315.0mm ( 41-9/16 x 11-3/4 x 12-3/8inch) .
Polk S55 is clearly the larger of the two speakers. Its body is 3mm wider, 162mm taller and 2mm deeper than KEF Q550.
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 Q550 is approximately 926.5cm2 / 143.6inch2 and base area of the Polk S55 is approximately 941.9cm2 / 146.0inch2. The Q550 requires 2% less surface area than the S55 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 Q550 weighs 14.55kg / 32lbs and the Polk S55 weighs 20.00kg / 44lbs. This makes the S55 37% heavier than the Q550.
Here is a comparison of how Q550 and S55's weights compare with the average, max and min weights in Passive Floor-standing class.
Weight
All Floor-standing Speakers
What's in the Box of KEF Q550?
Here are the items that are included inside the box of Q550:
Floorstanding loudspeaker2 Outrigger feet4 Spikes6 Screws6 Washers4 Rubber insertsHex-keyOwners ManualWarranty Information
What's in the Box of Polk S55?
Here are the items that come with the S55:
Floorstanding loudspeakerGrille (attached)4 Feet (pre-installed)Owners ManualOnline Product Registration
Passive Radiator |
2 x 5.25-inch
vs
None
|
Increases the bass performance |
Dolby Atmos Drivers |
Optional
vs
No
|
Dolby Atmos Compatibility |
Height |
894mm
vs
1056mm
|
Easier to fit in smaller spaces |
Base Surface Area |
926cm2 (296x313mm)
vs
941cm2 (299x315mm)
|
Takes less floor space |
Max Input Power |
200 watts
vs
130 watts
|
Handle more power from your amplifier |
Sensitivity |
90 dB
vs
87 dB
|
Play louder with same amount of amplification power |
Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
Low Frequency Response |
32 Hz
vs
58 Hz
|
Generates deeper bass |
High Frequency Response |
40k Hz
vs
28k Hz
|
Generates higher frequency |
Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
Price per pair* |
658USD
vs
1400USD
|
costs less (*prices may change depending on the seller, location and time) |
General |
KEF Q550 |
Polk Audio Signature S55 |
Brand |
KEF |
Polk Audio |
Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
Power Range |
15-130 watts |
20-200 watts |
Sensitivity |
87 dB |
90 dB |
Impedance |
8 ohms |
8 ohms |
Impedance |
3.5 ohms |
n/a |
Frequency Response |
58-28k Hz |
32-40k Hz |
Drivers |
|
|
Woofer Quantity |
2 |
2 |
Woofer Size |
5.25" |
6.5" |
Woofer Composition |
Aluminum |
Mica-reinforced polypropylene |
Woofer Surround Material |
Rubber |
Butyl rubber |
Tweeter Size |
1" |
1" |
Tweeter Type |
Dome |
Dome |
Aimable Tweeter |
No |
No |
Midrange Driver |
No |
No |
Crossover Frequency |
2500Hz |
2500Hz |
Firing Direction |
front |
bottom |
Physical Specs |
|
|
Height |
894.0mm (35.2") |
1056.0mm (41.6") |
Width |
296.0mm (11.7") |
299.0mm (11.8") |
Depth |
313.0mm (12.3") |
315.0mm (12.4") |
Weight |
14.55kg (32lbs) |
20.00kg (44lbs) |
Enclosure |
Passive Radiator |
Bass Reflex |
Finish |
MDF/Wood-grain vinyl |
Meddite MDF |
Available Colors |
Walnut |
Black |
Grille |
n/a |
Yes |
Moisture Resistancy |
No |
No |
Connections |
|
|
Biamp Inputs |
No |
Yes |
Other |
|
|
Parts Warranty |
5 Years |
5 Years |
Labor Warranty |
5 Years |
5 Years |