In this review, we will be comparing Q950 and S55, two Passive Floor-standing speakers from KEF and Polk Audio.
Let's have a brief look at the main features
of KEF Q950 and Polk S55 first before getting into our more
detailed comparison.
KEF Q950 Key Specs
- 2-way Design
- 11th Generation Uni-Q Driver
- 1.5" Dome Tweeter
- 2 x 8.0" Aluminum Woofer
- 44-28k Hz Frequency Response
- 91 dB Sensitivity
- Impedance: 8ohms
- Power Range:15-200watts
- Weight:20.68kg
- Dimensions (H x W x D): 1117.0" x 14-1/4" x 12-3/8"( 1117.0 x 362.0 x 315.0mm )
Polk S55 Key Specs
- 2-way Design
- 1" Dome Tweeter
- 2 x 6.5" Mica-reinforced polypropylene Woofer
- 32-40k Hz Frequency Response
- 90 dB Sensitivity
- Impedance: 8ohms
- Power Range:20-200watts
- Weight:20.00kg
- Dimensions (H x W x D): 1056.0" x 11-3/4" x 12-3/8"( 1056.0 x 299.0 x 315.0mm )
What size room are the KEF Q950 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:
| Listening Environment* |
KEF Q950 |
Polk S55 |
| Near-field |
Bad |
Bad |
| Small Room |
Poor |
Poor |
| Mid-size Room |
Good |
Good |
| Large Room |
Good |
Good |
| 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.)
In the following sections, we will get into more detail in order to better understand how the KEF Q950 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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through my links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both Q950 and S55 are 2-way speakers.
| Driver |
KEF Q950 |
Polk S55 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.5-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 8.0-inch
|
2 x 6.5-inch
|
Q950 features a 1.5" vented aluminum Dome Tweeter and 2 x 8.0" Aluminum Woofer with a Crossover frequency at 2200Hz. 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
Q950 has a frequency range of 44-28k 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 Q950's min frequency of 44Hz.
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
Q950 and S55 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Q950 sensitivity is rated at 91 dB and the S55's is at 90 dB. This 1 dB difference makes the KEF Q950 a more sensitive speaker compared to Polk S55, 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.
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. Q950 has a Binding post which doesn't feature bi-amping/bi-wiring.
Polk S55's 5-way post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Q950 has a front firing port whereas S55 has a bottom firing ports. KEF Q950's front-firing port gives more flexibility in placement in regards to proximity to walls compared to Polk S55 with its rear-firing port.
Polk S55 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 Q950's and Polk S55's external dimensions. KEF Q950 has external dimensions of 1117.0 x 362.0 x 315.0mm ( 43-15/16 x 14-1/4 x 12-3/8inch) 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 63mm narrower and 61mm shorter than KEF Q950 but they have the same thickness of 315.0mm.
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 Q950 is approximately 1140.3cm2 / 176.7inch2 and base area of the Polk S55 is approximately 941.9cm2 / 146.0inch2. The Q950 requires 21% more surface area than the S55 which gives it a small disadvantage on placement in tight spaces.