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.
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:
In the following sections, we will get into more detail in order to better understand how the KEF R3 and B&W 706 S2 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 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.
| 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.
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 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. 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 706 S2 has a max power handling value of 120 watts RMS, 60 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
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
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 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 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 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 loudspeakers2 Grilles2 Foam port plugs8 Self-adhesive rubber feetUser ManualWarranty Information
What's in the Box of B&W 706 S2?
Here are the items that come with the 706 S2:
2 Bookshelf loudspeakers2 Grilles2 Two-piece foam port plugs8 Self-adhesive rubber feet4 Jumper-straps Manual Bowers & Wilkins brochureWarranty 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 (200x301mm)
vs
670cm2 (199x337mm)
|
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 |