In this review, we will be comparing R3 and 706 S2, two Passive Bookshelf speakers from KEF and Bowers Wilkins.
Let's have a brief look at the main features
of KEF R3 and B&W 706 S2 first before getting into our more
detailed comparison.
| Key Specs | KEF R3 | B&W 706 S2 |
|---|
| Brand | KEF
United Kingdom · founded 1961 | Bowers Wilkins
United Kingdom · founded 1966 |
|---|
| Design | 3-way | 2-way |
|---|
| Uni-Q driver | 12th Generation Uni-Q | — |
|---|
| Tweeter | 1" Dome | 1" Decoupled Soft-Dome |
|---|
| Midrange | 5" | — |
|---|
| Woofer | 6.5" Hybrid aluminum | 6.5" Continuum |
|---|
| Frequency response | 52-28k Hz | 50-28k Hz |
|---|
| Sensitivity | 87 dB | 88 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 15-180 watts | 30-120 watts |
|---|
| Weight | 13.55kg / 29.8lbs | 8.05kg / 17.7lbs |
|---|
| 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 | 13.5" x 7.8" x 11.9"
340.0 x 200.0 x 301.0mm |
|---|
What size room are the KEF R3 and B&W 706 S2 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 |
B&W 706 S2 |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
Poor |
(* 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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through our links. As an Amazon Associate I earn from qualifying purchases.
Drivers
One of the fundamental differences between these two speakers is that R3 is a 3-way design whereas the 706 S2 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 R3B&W 706 S2
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 |
B&W 706 S2 |
|
Driver Setup
|
3-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
1 x 5-inch |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 6.5-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 706 S2 features a 1" Decoupled Soft-Dome Tweeter and 1 x 6.5" Continuum Woofer.
Frequency Response
R3 has a frequency range of 52-28k Hz whereas 706 S2 has a frequency range of 50-28k Hz. With a minimum frequency of 50Hz, the 706 S2 can go slightly deeper then the R3's min frequency of 52Hz.
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 706 S2 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. R3 sensitivity is rated at 87 dB and the 706 S2's is at 88 dB. This 1 dB difference makes the B&W 706 S2 a more sensitive speaker compared to KEF R3, 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 706 S2 has a max power handling value of 120 watts RMS, 60 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
Both R3 and 706 S2 features dual binding post speaker terminals for bi-amping or bi-wiring.
Cabinet Type and Port Position
Both R3 and 706 S2 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 B&W 706 S2'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 B&W 706 S2 has external dimensions of 340.0 x 200.0 x 301.0mm (13.5-inch x 7.8-inch x 11.-inch).
B&W 706 S2 is 83mm shorter and 36mm less deeper than KEF R3 but it is also 1mm wider.
Below you can see the front view size comparison of KEF R3 and B&W 706 S2 in scale.
Comparison image of KEF R3 and B&W 706 S2 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 B&W 706 S2 is approximately 602.0cm2 / 93.3inch2. The R3 requires 11% more surface area than the 706 S2 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 B&W 706 S2 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 B&W 706 S2 weighs 8.05kg / 17.7lbs. This makes the R3 68% heavier than the 706 S2.
Here is a comparison of how R3 and 706 S2'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 B&W 706 S2?
Here are the items that come with the 706 S2:
- 2 Bookshelf loudspeakers
- 2 Grilles
- 2 Two-piece foam port plugs
- 8 Self-adhesive rubber feet
- 4 Jumper-straps
- Manual
- Bowers & Wilkins brochure
- Warranty Information
 Max Input Power |
180 watts
vs
120 watts
|
Handle more power from your amplifier |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Sensitivity |
88 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 Minimum Impedance |
3.7 ohms
vs
3.2 ohms
|
Very low impedance levels puts more pressure on amplifier |
 Low Frequency Response |
50 Hz
vs
52 Hz
|
Generates deeper bass |
 Height |
340mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
602cm2
vs
670cm2
|
Takes less floor space |
 Price per pair* |
1999USD
vs
2200USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF R3 |
Bowers & Wilkins 706 S2 |
| Brand |
KEF |
Bowers Wilkins |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
15-180 watts |
30-120 watts |
| Sensitivity |
87 dB |
88 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.2 ohms |
3.7 ohms |
| Frequency Response |
52-28k Hz |
50-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Hybrid aluminum |
Continuum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Decoupled Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5" |
No |
| Crossover Frequency |
400Hz and 2900Hz |
n/a |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
423.0mm (16.7") |
340.0mm (13.4") |
| Width |
199.0mm (7.8") |
200.0mm (7.9") |
| Depth |
337.0mm (13.3") |
301.0mm (11.9") |
| Weight |
13.55kg (29.8lbs) |
8.05kg (17.7lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Lacquer |
MDF/Wood Veneer |
| Available Colors |
Black Gloss, White Gloss, Walnut |
Rosewood, Gloss Black, Satin White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
n/a |
24-26" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (52Hz vs 50Hz). |
| Amplifier needs | evenly matched | Similar sensitivity (87dB vs 88dB) - both want much the same power. |
| Headroom | A | KEF R3 takes more power (180W vs 120W) - more in hand in a big room. |
| Size | depends | B&W 706 S2 is easier to place; KEF R3 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | KEF R3: bi-amping; B&W 706 S2: bi-amping. B&W 706 S2 sits in a wider range (8 models), so a matched surround system is easier later. |
| Price | evenly matched | Much the same money ($2,200 vs $1,999 a pair). |
A KEF R3 B B&W 706 S2
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?
KEF R3 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does.
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.