In this review, we will be comparing LSX II and Navis ARB-51, two Powered Bookshelf speakers from KEF and ELAC. 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 and ELAC Navis ARB-51 first before getting into our more
detailed comparison.
KEF LSX II 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 4.2 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 )
ELAC Navis ARB-51 Key Specs
- 3-way Design
- 300-watt RMS( 600-watt Peak) Integrated Amplifier
- 1" Soft-Dome Tweeter
- 4" Midrange
- 5.25" Aluminum Woofer
- 4" Midrange
- 44-28k Hz Frequency Response
- Optional Bluetooth
- Weight:8.10kg
- Dimensions (H x W x D): 350.8" x 7.5625" x 11.3125"( 350.8 x 192.1 x 287.3mm )
In the following sections, we will get into more detail in order to better understand how the KEF LSX II and ELAC Navis ARB-51 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
One of the fundamental differences between these two speakers is that LSX II is a 2-way design whereas the Navis ARB-51 is a 3-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
| Driver |
KEF LSX II |
ELAC Navis ARB-51 |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
0.75-inch
|
1-inch
|
|
Midrange
|
- |
1 x 4-inch |
|
Woofer
|
1 x 4.5-inch
|
1 x 5.25-inch
|
LSX II features a 0.75" Aluminum Hard-Dome Tweeter and 1 x 4.5" Magnesium/Aluminium alloy Woofer . On the other hand, the Navis ARB-51 features a 1" Fabric Soft-Dome Tweeter , a 4" Midrange and 1 x 5.25" Aluminum Woofer .
Frequency Response
LSX II has a frequency range of 54-28k Hz whereas Navis ARB-51 has a frequency range of 44-28k Hz. With a minimum frequency of 44Hz, the Navis ARB-51 can go significantly deeper on the low side and provide stronger bass compared to the LSX II's min frequency of 54Hz.
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 and Navis ARB-51 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 LSX II 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 LSX II's and ELAC Navis ARB-51's external dimensions. KEF LSX II has external dimensions of 240 × 155 × 180 mm ( 9.5 × 6.1 × 7.1 inch) whereas ELAC Navis ARB-51 has external dimensions of 350.8 x 192.1 x 287.3mm ( 13.8125 x 7.5625 x 11.3125inch) .
ELAC Navis ARB-51 is clearly the larger of the two speakers. Its body is 37.1mm wider, 110.8mm taller and 107.3mm deeper than KEF LSX II.
Below you can see the front view size comparison of KEF LSX II and ELAC Navis ARB-51 in scale.
Comparison image of KEF LSX II and ELAC Navis ARB-51 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 is approximately 279.0cm2 / 43.2inch2 and base area of the ELAC Navis ARB-51 is approximately 551.9cm2 / 85.5inch2. The LSX II requires 49% less surface area than the Navis ARB-51 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 KEF LSX II and ELAC Navis ARB-51 on a Media Console