In this review, we will be comparing R3 and LS50, two Passive Bookshelf speakers by KEF Let's have a brief look at the main features
of KEF R3 and KEF LS50 first before getting into our more
detailed comparison.
KEF R3 Key Specs
- 3-way Design
- 1" Dome Tweeter
- 5" Midrange
- 6.5" Hybrid aluminum Woofer
- 52-28k Hz Frequency Response
- 87 dB Sensitivity
- Impedance: 8ohms
- Power Range:15-180watts
- Weight:13.55kg
- Dimensions (H x W x D): 423.0" x 7-13/16" x 13-1/4"( 423.0 x 199.0 x 337.0mm )
KEF LS50 Key Specs
- 2-way Design
- 11th Generation Uni-Q Driver
- 1" Vented dome Tweeter
- 5.25" Magnesium/aluminum alloy Woofer
- 79-28k Hz Frequency Response
- 85 dB Sensitivity
- Impedance: 8ohms
- Power Range:25-100watts
- Weight:7.20kg
- Dimensions (H x W x D): 302.0" x 7.8" x 10.9"( 302.0 x 200.0 x 278.0mm )
What size room are the KEF R3 and KEF LS50 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* |
KEF R3 |
KEF LS50 |
| 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 KEF R3 and KEF LS50 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 R3 is a 3-way design whereas the LS50 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 |
KEF R3 |
KEF LS50 |
|
Driver Setup
|
3-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
1 x 5-inch |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 5.25-inch
|
R3 features a 1" aluminum Dome Tweeter , a 5" Midrange and 1 x 6.5" Hybrid aluminum Woofer with a Crossover frequency at 400Hz and 2900Hz. On the other hand, the LS50 features a 1" Aluminum Vented dome Tweeter and 1 x 5.25" Magnesium/aluminum alloy Woofer with a Crossover frequency at 2200Hz.
Frequency Response
R3 has a frequency range of 52-28k Hz whereas LS50 has a frequency range of 79-28k Hz. With a minimum frequency of 52Hz, the R3 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
R3 and LS50 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. R3 sensitivity is rated at 87 dB and the LS50's is at 85 dB. This 2 dB difference makes the KEF R3 a more sensitive speaker compared to KEF LS50, 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.
R3 can handle a max power of 180 watts RMS from the amp the whereas LS50 has a max power handling value of 100 watts RMS, 80 watts less than the R3.
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
R3 features Binding post posts which make bi-amping or bi-wiring possible. LS50 has a Post which doesn't feature bi-amping/bi-wiring.
KEF LS50's Post terminals
Cabinet Type and Port Position
Both R3 and LS50 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 R3 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 R3's and KEF LS50's external dimensions. KEF R3 has external dimensions of 423.0 x 199.0 x 337.0mm ( 16-5/8 x 7-13/16 x 13-1/4inch) whereas KEF LS50 has external dimensions of 302.0 x 200.0 x 278.0mm ( 11.8 x 7.8 x 10.9inch) .
KEF LS50 is 121mm shorter and 59mm less deeper than KEF R3 but it is also 1mm wider.
Below you can see the front view size comparison of KEF R3 and KEF LS50 in scale.
Comparison image of KEF R3 and KEF LS50 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 R3 is approximately 670.6cm2 / 103.9inch2 and base area of the KEF LS50 is approximately 556.0cm2 / 86.2inch2. The R3 requires 21% more surface area than the LS50 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 R3 and KEF LS50 on a Media Console
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 R3 weighs 13.55kg / 29.8lbs and the KEF LS50 weighs 7.20kg / 15.8lbs. This makes the R3 88% heavier than the LS50.
Here is a comparison of how R3 and LS50'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 R3?
Here are the items that are included inside the box of R3:
2 Bookshelf loudspeakers2 Grilles2 Foam port plugs8 Self-adhesive rubber feetUser ManualWarranty Information
What's in the Box of KEF LS50?
Here are the items that come with the LS50:
2 Bookshelf loudspeakers 2 Foam port plugs 8 Self-adhesive rubber feet Owner's Manual Warranty Registration Card