In this review, we will be comparing LSX II LT and Alpha iQ, two Powered Bookshelf speakers from KEF and PSB. Being Powered speakers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them.
Let's have a brief look at the main features
of KEF LSX II LT and PSB Alpha iQ first before getting into our more
detailed comparison.
KEF LSX II LT Key Specs
- 2-way Design
- 200-watt RMS Integrated Amplifier
- 11th Generation Uni-Q Driver
- 0.75" Hard-Dome Tweeter
- 4.5" Magnesium/Aluminium alloy Woofer
- 54-28k Hz Frequency Response
- 24-bit Max Depth / 384 kHz Max Sample Rate
- Built-in 5.0 Bluetooth
- App Control Feature
- Weight:3.60kg
- Dimensions (H x W x D): 240.0" x 6.1" x 7.1"( 240 × 155 × 180 mm )
PSB Alpha iQ Key Specs
- 2-way Design
- 180-watt RMS Integrated Amplifier
- 0.75" Hard-Dome Tweeter
- 4" Polypropylene Woofer
- 64-20kHz Frequency Response
- 24-bit Max Depth / 192 kHz Max Sample Rate
- Built-in Bluetooth
- App Control Feature
- Weight:7.36kg
- Dimensions (H x W x D): 246.0" x 5.6" x 7.6"( 246 x 145 x 92mm )
In the following sections, we will get into more detail in order to better understand how the KEF LSX II LT and PSB Alpha iQ 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 LSX II LT and Alpha iQ are 2-way speakers.
| Driver |
KEF LSX II LT |
PSB Alpha iQ |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
0.75-inch
|
0.75-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 4.5-inch
|
1 x 4-inch
|
LSX II LT features a 0.75" Aluminum Hard-Dome Tweeter and 1 x 4.5" Magnesium/Aluminium alloy Woofer . On the other hand, the Alpha iQ features a 0.75" aluminum Hard-Dome Tweeter and 1 x 4" Polypropylene Woofer .
Frequency Response
LSX II LT has a frequency range of 54-28k Hz whereas Alpha iQ has a frequency range of 64-20kHz. With a minimum frequency of 54Hz, the LSX II LT can go significantly deeper on the low side and provide stronger bass compared to the Alpha iQ's min frequency of 64Hz.
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.
Cabinet Type and Port Position
Both LSX II LT and Alpha iQ 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.
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 LSX II LT's and PSB Alpha iQ's external dimensions. KEF LSX II LT has external dimensions of 240 × 155 × 180 mm ( 9.5 × 6.1 × 7.1 inch) whereas PSB Alpha iQ has external dimensions of 246 x 145 x 92mm ( 9.7 x -5.6 x 7.6 inch ) .
KEF LSX II LT is 6mm shorter and 12mm less deeper than PSB Alpha iQ but it is also 10mm wider.
Below you can see the front view size comparison of KEF LSX II LT and PSB Alpha iQ in scale.
Comparison image of KEF LSX II LT and PSB Alpha iQ 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 KEF LSX II LT is approximately 279.0cm2 / 43.2inch2 and base area of the PSB Alpha iQ is approximately 278.0cm2 / 43.1inch2. The LSX II LT requires 0% more surface area than the Alpha iQ which gives it a small disadvantage 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 KEF LSX II LT and PSB Alpha iQ on a Media Console