In this review, we will be comparing 607 S2 AE and LS50, two Passive Bookshelf speakers from Bowers Wilkins and KEF.
Let's have a brief look at the main features
of B&W 607 S2 and KEF LS50 first before getting into our more
detailed comparison.
| Key Specs | B&W 607 S2 | KEF LS50 |
|---|
| Brand | Bowers Wilkins
United Kingdom · founded 1966 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | — | 11th Generation Uni-Q |
|---|
| Tweeter | 1" Decoupled Double Dome | 1" Vented dome |
|---|
| Woofer | 5" Continuum | 5.25" Magnesium/aluminum alloy |
|---|
| Frequency response | 52-28k Hz | 79-28k Hz |
|---|
| Sensitivity | 84 dB | 85 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 30-100 watts | 25-100 watts |
|---|
| Weight | 4.70kg / 10.3lbs | 7.20kg / 15.8lbs |
|---|
| Dimensions (H x W x D) | 11-13/16" x 6-1/2" x 9-1/8"
301.0 x 166.0 x 232.0mm | 11.8" x 7.8" x 10.9"
302.0 x 200.0 x 278.0mm |
|---|
What size room are the B&W 607 S2 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* |
B&W 607 S2 |
KEF LS50 |
| Near-field |
Average |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
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.
Drivers
Both 607 S2 AE and LS50 are 2-way speakers.
B&W 607 S2KEF LS50
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
B&W 607 S2 |
KEF LS50 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5-inch
|
1 x 5.25-inch
|
607 S2 AE features a 1" Aluminum Decoupled Double Dome Tweeter and 1 x 5" Continuum Woofer. 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
607 S2 AE 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 607 S2 AE 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
607 S2 AE and LS50 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. 607 S2 AE sensitivity is rated at 84 dB and the LS50's is at 85 dB. This 1 dB difference makes the KEF LS50 a more sensitive speaker compared to B&W 607 S2, 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.
Both handle the same maximum of 100 watts RMS, though 607 S2 AE is rated 30-100 watts and LS50 25-100 watts.
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
607 S2 AE features Binding post posts which make bi-amping or bi-wiring possible. LS50 has a Post which doesn't feature bi-amping/bi-wiring.
B&W 607 S2's Binding post terminals allows Bi-amping or bi-wiring
KEF LS50's Post terminals
Cabinet Type and Port Position
Both 607 S2 AE 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.
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 B&W 607 S2's and KEF LS50's external dimensions. B&W 607 S2 has external dimensions of 301.0 x 166.0 x 232.0mm (11-13/16 x 6-1/2 x 9-1/8inch) 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 clearly the larger of the two speakers. Its body is 34mm wider, 1mm taller and 46mm deeper than B&W 607 S2.
Below you can see the front view size comparison of B&W 607 S2 and KEF LS50 in scale.
Comparison image of B&W 607 S2 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 B&W 607 S2 is approximately 385.1cm2 / 59.7inch2 and base area of the KEF LS50 is approximately 556.0cm2 / 86.2inch2. The 607 S2 AE requires 31% less surface area than the LS50 which gives it a small advantage 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 B&W 607 S2 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 B&W 607 S2 weighs 4.70kg / 10.3lbs and the KEF LS50 weighs 7.20kg / 15.8lbs. This makes the LS50 53% heavier than the 607 S2 AE.
Here is a comparison of how 607 S2 AE 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 B&W 607 S2?
Here are the items that are included inside the box of 607 S2 AE:
- 2 Bookshelf loudspeakers
- 2 Grilles
- 2 Two-piece foam port plugs
- 8 Self-adhesive rubber feet
- 4 Jumper-straps (pre-installed)
- Manual
- Bowers & Wilkins brochure
- 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
 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 |
301mm
vs
302mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
385cm2
vs
556cm2
|
Takes less floor space |
 Price per pair* |
799USD
vs
1300USD
|
costs less (*prices may change depending on the seller, location and time) |
 Sensitivity |
85 dB
vs
84 dB
|
Play louder with same amount of amplification power |
 Minimum Impedance |
3.2 ohms
vs
3.0 ohms
|
Very low impedance levels puts more pressure on amplifier |
|
Woofer Size |
5.25 inches
vs
5 inches
|
Larger woofer |
| General |
Bowers & Wilkins 607 S2 Anniversary Edition |
KEF LS50 |
| Brand |
Bowers Wilkins |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
30-100 watts |
25-100 watts |
| Sensitivity |
84 dB |
85 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.0 ohms |
3.2 ohms |
| Frequency Response |
52-28k Hz |
79-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5" |
5.25" |
| Woofer Composition |
Continuum |
Magnesium/aluminum alloy |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Decoupled Double Dome |
Vented dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2200Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
301.0mm (11.9") |
302.0mm (11.9") |
| Width |
166.0mm (6.5") |
200.0mm (7.9") |
| Depth |
232.0mm (9.1") |
278.0mm (10.9") |
| Weight |
4.70kg (10.3lbs) |
7.20kg (15.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Vinyl |
Polymer/Lacquer |
| Available Colors |
Matte Black, Matte White, Oak, Red Cherry |
Black, High Gloss Piano Black, High Gloss Piano White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
24-26" |
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 LS50 costs roughly 1.6x what B&W 607 S2 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 | B&W 607 S2 digs deeper - 52Hz against 79Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (84dB vs 85dB) - both want much the same power. |
| Headroom | evenly matched | Similar power handling (100W vs 100W). |
| Size | depends | B&W 607 S2 is easier to place; KEF LS50 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | B&W 607 S2: bi-amping. KEF LS50 sits in a wider range (10 models), so a matched surround system is easier later. |
| Price | A | B&W 607 S2 is cheaper - $799 against $1,300, about 39% less; arguably a different class. |
A B&W 607 S2 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?
B&W 607 S2 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 79Hz anyway, so judge these on the other rows instead. In a large or open-plan room, KEF LS50 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, B&W 607 S2 is the easier speaker to get right.
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.