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.
| Key Specs | KEF R3 | KEF LS50 |
|---|
| Brand | KEF
United Kingdom · founded 1961 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 3-way | 2-way |
|---|
| Uni-Q driver | 12th Generation Uni-Q | 11th Generation Uni-Q |
|---|
| Tweeter | 1" Dome | 1" Vented dome |
|---|
| Midrange | 5" | — |
|---|
| Woofer | 6.5" Hybrid aluminum | 5.25" Magnesium/aluminum alloy |
|---|
| Frequency response | 52-28k Hz | 79-28k Hz |
|---|
| Sensitivity | 87 dB | 85 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 15-180 watts | 25-100 watts |
|---|
| Weight | 13.55kg / 29.8lbs | 7.20kg / 15.8lbs |
|---|
| Dimensions (H x W x D) | 16-5/8" x 7-13/16" x 13-1/4"
423.0 x 199.0 x 337.0mm | 11.8" 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.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
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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.
KEF R3KEF LS50
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| 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.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf Speakers
Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. 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. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
R3 can handle a max power of 180 watts RMS, whereas LS50 has a max power handling value of 100 watts RMS, 80 watts less than the R3.
Note that higher power handling does not make a speaker louder: that depends mainly on
sensitivity and impedance. The calculator below shows how loud each of these actually plays
on a real amplifier.
Which plays louder on your amplifier?
Starting with a popular amplifier - change it to the one you own, or any you are
considering, and watch both numbers move.
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
The size of a speaker can sometimes be 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 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 loudspeakers
- 2 Grilles
- 2 Foam port plugs
- 8 Self-adhesive rubber feet
- User Manual
- Warranty 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
 Max Input Power |
180 watts
vs
100 watts
|
Handle more power from your amplifier |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
|
Uni-Q Driver |
12th Generation
vs
11th Generation
|
Newer generation Driver |
 Sensitivity |
87 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
52 Hz
vs
79 Hz
|
Generates deeper bass |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Height |
302mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
556cm2
vs
670cm2
|
Takes less floor space |
 Price per pair* |
1300USD
vs
2200USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF R3 |
KEF LS50 |
| Brand |
KEF |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
15-180 watts |
25-100 watts |
| Sensitivity |
87 dB |
85 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.2 ohms |
3.2 ohms |
| Frequency Response |
52-28k Hz |
79-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
5.25" |
| Woofer Composition |
Hybrid aluminum |
Magnesium/aluminum alloy |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Vented dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5" |
No |
| Crossover Frequency |
400Hz and 2900Hz |
2200Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
423.0mm (16.7") |
302.0mm (11.9") |
| Width |
199.0mm (7.8") |
200.0mm (7.9") |
| Depth |
337.0mm (13.3") |
278.0mm (10.9") |
| Weight |
13.55kg (29.8lbs) |
7.20kg (15.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Lacquer |
Polymer/Lacquer |
| Available Colors |
Black Gloss, White Gloss, Walnut |
Black, High Gloss Piano Black, High Gloss Piano White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
n/a |
18-28" |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
These sit in different price classes - KEF R3 costs roughly 1.7x what KEF LS50 does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | A | KEF R3 digs deeper - 52Hz against 79Hz. |
| Amplifier needs | A | KEF R3 is more sensitive (87dB vs 85dB), so it goes louder on the same amplifier. |
| Headroom | A | KEF R3 takes more power (180W vs 100W) - more in hand in a big room. |
| Size | depends | KEF LS50 is easier to place; KEF R3 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | KEF R3: bi-amping. KEF LS50 sits in a wider range (10 models), so a matched surround system is easier later. |
| Price | B | KEF LS50 is cheaper - $1,300 against $2,200, about 41% less; arguably a different class. |
A KEF R3 B KEF LS50
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
The usual trade-off: KEF R3 measures better, KEF LS50 costs about about 69% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 79Hz anyway, which makes the cheaper KEF LS50 much easier to justify. Match it to your room: we rate KEF R3 the better fit for a mid-size room and a large room, and KEF LS50 for near-field listening and a small room.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.