In this review, we will be comparing Alpha P3 and Q150, two Passive Bookshelf speakers from PSB and KEF.
Let's have a brief look at the main features
of PSB P3 and KEF Q150 first before getting into our more
detailed comparison.
PSB P3 Key Specs
- 2-way Design
- 0.75" Hard-Dome Tweeter
- 4.5" Polypropylene Woofer
- 57-21k Hz Frequency Response
- 87 dB Sensitivity
- Impedance: 8ohms
- Power Range:10-80watts
- Weight:2.23kg
- Dimensions (H x W x D): 223.0" x 5-3/16" x 7-5/16"( 223.0 x 132.0 x 186.0mm )
KEF Q150 Key Specs
- 2-way Design
- 11th Generation Uni-Q Driver
- 1" Dome Tweeter
- 5.25" Aluminum Woofer
- 51-28k Hz Frequency Response
- 86 dB Sensitivity
- Impedance: 8ohms
- Power Range:10-100watts
- Weight:5.60kg
- Dimensions (H x W x D): 303.0" x 7.0" x 10.9"( 303.0 x 180.0 x 278.0mm )
What size room are the PSB P3 and KEF Q150 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* |
PSB P3 |
KEF Q150 |
| Near-field |
Average |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
Bad |
(* 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 PSB P3 and KEF Q150 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 Alpha P3 and Q150 are 2-way speakers.
| Driver |
PSB P3 |
KEF Q150 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
0.75-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 4.5-inch
|
1 x 5.25-inch
|
Alpha P3 features a 0.75" anodized aluminum Hard-Dome Tweeter and 1 x 4.5" Polypropylene Woofer with a Crossover frequency at 3000Hz. On the other hand, the Q150 features a 1" vented aluminum Dome Tweeter and 1 x 5.25" Aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Alpha P3 has a frequency range of 57-21k Hz whereas Q150 has a frequency range of 51-28k Hz. With a minimum frequency of 51Hz, the Q150 can go significantly deeper on the low side and provide stronger bass compared to the Alpha P3's min frequency of 57Hz.
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 Bookshelf class in our database.
Low Frequency
Bookshelf Speakers
High Frequency
Bookshelf 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
Alpha P3 and Q150 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Alpha P3 sensitivity is rated at 87 dB and the Q150's is at 86 dB. This 1 dB difference makes the PSB P3 a more sensitive speaker compared to KEF Q150, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf 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.
Alpha P3 can handle a max power of 100 watts RMS from the amp the whereas Alpha P3 has a max power handling value of 80 watts RMS , 20 watts less than the Q150.
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
Alpha P3 features Post type posts and Q150 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
PSB P3's 5-way post terminals
KEF Q150's Post terminals
Cabinet Type and Port Position
Both Alpha P3 and Q150 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 Q150 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 PSB P3's and KEF Q150's external dimensions. PSB P3 has external dimensions of 223.0 x 132.0 x 186.0mm ( 8-3/4 x 5-3/16 x 7-5/16inch) whereas KEF Q150 has external dimensions of 303.0 x 180.0 x 278.0mm ( 11.9 x 7.0 x 10.9inch) .
KEF Q150 is clearly the larger of the two speakers. Its body is 48mm wider, 80mm taller and 92mm deeper than PSB P3.
Below you can see the front view size comparison of PSB P3 and KEF Q150 in scale.
Comparison image of PSB P3 and KEF Q150 Size and External Dimensions
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 PSB P3 is approximately 245.5cm2 / 38.1inch2 and base area of the KEF Q150 is approximately 500.4cm2 / 77.6inch2. The Alpha P3 requires 51% less surface area than the Q150 which gives it a small advantage on placement in tight spaces.
Here is an another comparison that shows both speakers on a BDI Octave Media Cabinet, next to a standard size amplifier and turntable in scale:
Size Comparison image of PSB P3 and KEF Q150 on a Media Console