In this review, we will be comparing 705 S3 Signature and R3, two Passive Bookshelf speakers from Bowers Wilkins and KEF.
Let's have a brief look at the main features
of Bowers & Wilkins 705 S3 Signature and KEF R3 first before getting into our more
detailed comparison.
| Key Specs | Bowers & Wilkins 705 S3 Signature | KEF R3 |
|---|
| Brand | Bowers Wilkins
United Kingdom · founded 1966 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 3-way |
|---|
| Uni-Q driver | — | 12th Generation Uni-Q |
|---|
| Tweeter | 1" Decoupled Carbon Dome | 1" Dome |
|---|
| Midrange | — | 5" |
|---|
| Woofer | 6.5" Continuum | 6.5" Hybrid aluminum |
|---|
| Frequency response | 50-28k Hz | 52-28k Hz |
|---|
| Sensitivity | 88 dB | 87 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 30-120 watts | 15-180 watts |
|---|
| Weight | 10.35kg / 22.8lbs | 13.55kg / 29.8lbs |
|---|
| Dimensions (H x W x D) | 16-1/4" x 7-9/16" x 11-11/16"
413.0 x 192.0 x 297.0mm | 16-5/8" x 7-13/16" x 13-1/4"
423.0 x 199.0 x 337.0mm |
|---|
What size room are the Bowers & Wilkins 705 S3 Signature and KEF R3 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* |
Bowers & Wilkins 705 S3 Signature |
KEF R3 |
| Near-field |
Average |
Poor |
| Small Room |
Good |
Average |
| Mid-size Room |
Average |
Good |
| Large Room |
Poor |
Average |
| Very Large Room |
Bad |
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.
Drivers
One of the fundamental differences between these two speakers is that 705 S3 Signature is a 2-way design whereas the R3 is a 3-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.
Bowers & Wilkins 705 S3 SignatureKEF R3
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Bowers & Wilkins 705 S3 Signature |
KEF R3 |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
1 x 5-inch |
|
Woofer
|
1 x 6.5-inch
|
1 x 6.5-inch
|
705 S3 Signature features a 1" Carbon Decoupled Carbon Dome Tweeter and 1 x 6.5" Continuum Woofer. On the other hand, the 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.
Frequency Response
705 S3 Signature has a frequency range of 50-28k Hz whereas R3 has a frequency range of 52-28k Hz. With a minimum frequency of 50Hz, the 705 S3 Signature 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
705 S3 Signature and R3 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. 705 S3 Signature sensitivity is rated at 88 dB and the R3's is at 87 dB. This 1 dB difference makes the Bowers & Wilkins 705 S3 Signature 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 705 S3 Signature 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.
Bowers & Wilkins 705 S3 Signature
Input Type and Bi-Amping / Bi-Wiring
Both 705 S3 Signature and R3 features dual binding post speaker terminals for bi-amping or bi-wiring.
Cabinet Type and Port Position
Both 705 S3 Signature and R3 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 Bowers & Wilkins 705 S3 Signature's and KEF R3's external dimensions. Bowers & Wilkins 705 S3 Signature has external dimensions of 413.0 x 192.0 x 297.0mm (16-1/4 x 7-9/16 x 11-11/16inch) whereas 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).
KEF R3 is clearly the larger of the two speakers. Its body is 7mm wider, 10mm taller and 40mm deeper than Bowers & Wilkins 705 S3 Signature.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
KEF R3 needs about 18% more floor or shelf area. KEF R3 is 40mm deeper, so it stands that much further out from the wall.
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 Bowers & Wilkins 705 S3 Signature is approximately 570.2cm2 / 88.4inch2 and base area of the KEF R3 is approximately 670.6cm2 / 103.9inch2. The 705 S3 Signature requires 15% less surface area than the R3 which gives it a small advantage on placement in tight spaces.
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 Bowers & Wilkins 705 S3 Signature weighs 10.35kg / 22.8lbs and the KEF R3 weighs 13.55kg / 29.8lbs. This makes the R3 31% heavier than the 705 S3 Signature.
Here is a comparison of how 705 S3 Signature and R3's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
Bowers & Wilkins 705 S3 Signature
What's in the Box of KEF R3?
Here are the items that come with the R3:
- 2 Bookshelf loudspeakers
- 2 Grilles
- 2 Foam port plugs
- 8 Self-adhesive rubber feet
- User Manual
- Warranty Information
 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 |
413mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
570cm2
vs
670cm2
|
Takes less floor space |
 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 |
 Price per pair* |
2200USD
vs
5200USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Bowers & Wilkins 705 S3 Signature |
KEF R3 |
| Brand |
Bowers Wilkins |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
30-120 watts |
15-180 watts |
| Sensitivity |
88 dB |
87 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.7 ohms |
3.2 ohms |
| Frequency Response |
50-28k Hz |
52-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Continuum |
Hybrid aluminum |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Decoupled Carbon Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
5" |
| Crossover Frequency |
n/a |
400Hz and 2900Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
413.0mm (16.3") |
423.0mm (16.7") |
| Width |
192.0mm (7.6") |
199.0mm (7.8") |
| Depth |
297.0mm (11.7") |
337.0mm (13.3") |
| Weight |
10.35kg (22.8lbs) |
13.55kg (29.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
MDF/Lacquer |
| Available Colors |
n/a |
Black Gloss, White Gloss, Walnut |
| Mounting Bracket |
|
No |
| 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 |
These sit in different price classes - Bowers & Wilkins 705 S3 Signature costs roughly 2.4x what KEF R3 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 | evenly matched | Much the same reach (50Hz vs 52Hz). |
| Amplifier needs | evenly matched | Similar sensitivity (88dB vs 87dB) - both want much the same power. |
| Headroom | B | KEF R3 takes more power (180W vs 120W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | Bowers & Wilkins 705 S3 Signature: bi-amping; KEF R3: bi-amping. |
| Price | B | KEF R3 is cheaper - $2,200 against $5,200, about 58% less; arguably a different class. |
A Bowers & Wilkins 705 S3 Signature B KEF R3
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. Match it to your room: we rate Bowers & Wilkins 705 S3 Signature the better fit for near-field listening and a small room, and KEF R3 for a mid-size room and a large room. Think about the whole system, not just the speakers: the roughly $3,000 saved by taking the cheaper pair would buy a subwoofer or a better amplifier, and either usually does more for the sound than the difference between these two.
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.