In this review, we will be comparing Uni-Fi BS U5 Slim and Q150, two Passive Bookshelf speakers from ELAC and KEF.
Let's have a brief look at the main features
of ELAC Uni-Fi BS U5 Slim and KEF Q150 first before getting into our more
detailed comparison.
ELAC Uni-Fi BS U5 Slim Key Specs
- 3-way Design
- 1" soft dome Tweeter
- 4" Midrange
- 5.25" Aluminum Woofer
- 46-25k Hz Frequency Response
- 85 dB Sensitivity
- Impedance: 4ohms
- Power Range:40-140watts
- Weight:7.50kg
- Dimensions (H x W x D): 340.0" x 7-1/16" x 12-7/8"( 340.0 x 180.0 x 328.0mm )
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 ELAC Uni-Fi BS U5 Slim 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* |
ELAC Uni-Fi BS U5 Slim |
KEF Q150 |
| Near-field |
Poor |
Average |
| Small Room |
Average |
Good |
| Mid-size Room |
Good |
Average |
| Large Room |
Average |
Poor |
| Very Large Room |
Poor |
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 ELAC Uni-Fi BS U5 Slim and KEF Q150 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
**This post contains affiliate links, and I will be compensated if you make a purchase after clicking
through my links. As an Amazon Associate I earn from qualifying purchases.
Drivers
One of the fundamental differences between these two speakers is that Uni-Fi BS U5 Slim is a 3-way design whereas the Q150 is a 2-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 |
ELAC Uni-Fi BS U5 Slim |
KEF Q150 |
|
Driver Setup
|
3-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
1 x 4-inch |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 5.25-inch
|
Uni-Fi BS U5 Slim features a 1" soft dome Tweeter , a 4" Midrange and 1 x 5.25" Aluminum Woofer . 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
Uni-Fi BS U5 Slim has a frequency range of 46-25k Hz whereas Q150 has a frequency range of 51-28k 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 Q150's min frequency of 51Hz.
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
Uni-Fi BS U5 Slim is a 4 ohms speaker compared to the Q150 which has a nominal impedance of 8 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.
These two speakers also have different sensitivity levels. Uni-Fi BS U5 Slim sensitivity is rated at 85 dB and the Q150's is rated at 86 dB. This 1 dB difference makes the KEF Q150 a more sensitive speaker compared to ELAC Uni-Fi BS U5 Slim, 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.
Uni-Fi BS U5 Slim can handle a max power of 140 watts RMS from the amp the whereas Q150 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
Uni-Fi BS U5 Slim features Post type posts and Q150 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
ELAC Uni-Fi BS U5 Slim's Post terminals
KEF Q150's Post terminals
Cabinet Type and Port Position
Both Uni-Fi BS U5 Slim 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 ELAC Uni-Fi BS U5 Slim's and KEF Q150's external dimensions. 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) whereas KEF Q150 has external dimensions of 303.0 x 180.0 x 278.0mm ( 11.9 x 7.0 x 10.9inch) .
Below you can see the front view size comparison of ELAC Uni-Fi BS U5 Slim and KEF Q150 in scale.
Comparison image of ELAC Uni-Fi BS U5 Slim 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 ELAC Uni-Fi BS U5 Slim is approximately 590.4cm2 / 91.5inch2 and base area of the KEF Q150 is approximately 500.4cm2 / 77.6inch2. The Uni-Fi BS U5 Slim requires 18% more surface area than the Q150 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 ELAC Uni-Fi BS U5 Slim and KEF Q150 on a Media Console