In this review, we will be comparing LS50 and Uni-Fi BS U5 Slim, two Passive Bookshelf speakers from KEF and ELAC. Let's have a brief look at the main features
of KEF LS50 and ELAC Uni-Fi BS U5 Slim first before getting into our more
detailed comparison.
What size room are the KEF LS50 and ELAC Uni-Fi BS U5 Slim 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 LS50 and ELAC Uni-Fi BS U5 Slim 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 LS50 is a 2-way design whereas the Uni-Fi BS U5 Slim 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 LS50 |
ELAC Uni-Fi BS U5 Slim |
Driver Setup
|
2-way
|
3-way
|
Tweeter
|
1-inch
|
1-inch
|
Midrange
|
- |
1 x 4-inch |
Woofer
|
1 x 5.25-inch
|
1 x 5.25-inch
|
LS50 features a 1" Aluminum Vented dome Tweeter and 1 x 5.25" Magnesium/aluminum alloy Woofer with a Crossover frequency at 2200Hz. On the other hand, the Uni-Fi BS U5 Slim features a 1" soft dome Tweeter , a 4" Midrange and 1 x 5.25" Aluminum Woofer .
Frequency Response
LS50 has a frequency range of 79-28k Hz whereas Uni-Fi BS U5 Slim has a frequency range of 46-25k Hz. With a minimum frequency of 46Hz, the Uni-Fi BS U5 Slim can go significantly deeper on the low side and provide stronger bass compared to the LS50's min frequency of 79Hz.
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
LS50 is a 8 ohms speaker compared to the Uni-Fi BS U5 Slim which has a nominal impedance of 4 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the Uni-Fi BS U5 Slim can provide this impedance level.
On the other hand, they have the same sensitivity of 85 dBdB.
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.
LS50 can handle a max power of 140 watts RMS from the amp the whereas LS50 has a max power handling value of 100 watts RMS , 40 watts less than the Uni-Fi BS U5 Slim.
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
LS50 features Post type posts and Uni-Fi BS U5 Slim has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
Cabinet Type and Port Position
Both LS50 and Uni-Fi BS U5 Slim 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 LS50's and ELAC Uni-Fi BS U5 Slim's external dimensions. KEF LS50 has external dimensions of 302.0 x 200.0 x 278.0mm ( 11.8 x 7.8 x 10.9inch) whereas ELAC Uni-Fi BS U5 Slim has external dimensions of 340.0 x 180.0 x 328.0mm ( 13-3/8 x 7-1/16 x 12-7/8inch) .
KEF LS50 is 38mm shorter and 50mm less deeper than ELAC Uni-Fi BS U5 Slim but it is also 20mm wider.
Below you can see the front view size comparison of KEF LS50 and ELAC Uni-Fi BS U5 Slim in scale.
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 LS50 is approximately 556.0cm2 / 86.2inch2 and base area of the ELAC Uni-Fi BS U5 Slim is approximately 590.4cm2 / 91.5inch2. The LS50 requires 6% less surface area than the Uni-Fi BS U5 Slim 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:
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 LS50 weighs 7.20kg / 15.8lbs and the ELAC Uni-Fi BS U5 Slim weighs 7.50kg / 16.5lbs. This makes the Uni-Fi BS U5 Slim 4% heavier than the LS50.
Here is a comparison of how LS50 and Uni-Fi BS U5 Slim's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of KEF LS50?
Here are the items that are included inside the box of LS50:
2 Bookshelf loudspeakers 2 Foam port plugs 8 Self-adhesive rubber feet Owner's Manual Warranty Registration Card
What's in the Box of ELAC Uni-Fi BS U5 Slim?
Here are the items that come with the Uni-Fi BS U5 Slim:
2 Bookshelf loudspeakers 2 Grilles Operating Instructions
Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
High Frequency Response |
28k Hz
vs
25k Hz
|
Generates higher frequency |
Height |
302mm
vs
340mm
|
Easier to fit in smaller spaces |
Base Surface Area |
556cm2 (200x278mm)
vs
590cm2 (180x328mm)
|
Takes less floor space |
Max Input Power |
140 watts
vs
100 watts
|
Handle more power from your amplifier |
Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
Low Frequency Response |
46 Hz
vs
79 Hz
|
Generates deeper bass |
General |
KEF LS50 |
ELAC Uni-Fi BS U5 Slim |
Brand |
KEF |
ELAC |
Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
Power Range |
25-100 watts |
40-140 watts |
Sensitivity |
85 dB |
85 dB |
Impedance |
8 ohms |
4 ohms |
Impedance |
3.2 ohms |
n/a |
Frequency Response |
79-28k Hz |
46-25k Hz |
Drivers |
|
|
Woofer Quantity |
1 |
1 |
Woofer Size |
5.25" |
5.25" |
Woofer Composition |
Magnesium/aluminum alloy |
Aluminum |
Woofer Surround Material |
Rubber |
Rubber |
Tweeter Size |
1" |
1" |
Tweeter Type |
Vented dome |
soft dome |
Aimable Tweeter |
No |
No |
Midrange Driver |
No |
4" |
Crossover Frequency |
2200Hz |
n/a |
Firing Direction |
rear |
rear |
Physical Specs |
|
|
Height |
302.0mm (11.9") |
340.0mm (13.4") |
Width |
200.0mm (7.9") |
180.0mm (7.1") |
Depth |
278.0mm (10.9") |
328.0mm (12.9") |
Weight |
7.20kg (15.8lbs) |
7.50kg (16.5lbs) |
Enclosure |
Bass Reflex |
Bass Reflex |
Finish |
Polymer/Lacquer |
MDF/Vinyl |
Available Colors |
Black, High Gloss Piano Black, High Gloss Piano White |
Black |
Mounting Bracket |
No |
No |
Recommended Stand Height |
18-28" |
24-31" |
Grille |
n/a |
Yes |
Moisture Resistancy |
No |
No |
Connections |
|
|
Biamp Inputs |
No |
No |
Other |
|
|
Parts Warranty |
5 Years |
3 Years |
Labor Warranty |
5 Years |
3 Years |