In this review, we will be comparing 706 S2 and Q350, two Passive Bookshelf speakers from Bowers Wilkins and KEF. Let's have a brief look at the main features
of B&W 706 S2 and KEF Q350 first before getting into our more
detailed comparison.
What size room are the B&W 706 S2 and KEF Q350 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 B&W 706 S2 and KEF Q350 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
Both 706 S2 and Q350 are 2-way speakers. 706 S2 features a 1" Decoupled Soft-Dome Tweeter and 1 x 6.5" Continuum Woofer . On the other hand, the Q350 features a 1" vented aluminum Dome Tweeter and 1 x 6.5" Aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
706 S2 has a frequency range of 50-28k Hz whereas Q350 has a frequency range of 63-28k Hz. With a minimum frequency of 50Hz, the 706 S2 can go significantly deeper on the low side and provide stronger bass compared to the Q350's min frequency of 63Hz.
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
706 S2 and Q350 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. 706 S2 sensitivity is rated at 88 dB and the Q350's is at 87 dB. This 1 dB difference makes the B&W 706 S2 a more sensitive speaker compared to KEF Q350, 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.
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
706 S2 features Binding post posts which make bi-amping or bi-wiring possible. Q350 has a Post which doesn't feature bi-amping/bi-wiring.
KEF Q350's Post terminals
Cabinet Type and Port Position
Both 706 S2 and Q350 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.
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 B&W 706 S2's and KEF Q350's external dimensions. 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) whereas KEF Q350 has external dimensions of 358.0 x 210.0 x 306.0mm ( 14.0 x 8.2 x 12.0inch) .
KEF Q350 is clearly the larger of the two speakers. Its body is 10mm wider, 18mm taller and 5mm deeper than B&W 706 S2.
Below you can see the front view size comparison of B&W 706 S2 and KEF Q350 in scale.
Comparison image of B&W 706 S2 and KEF Q350 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 706 S2 is approximately 602.0cm2 / 93.3inch2 and base area of the KEF Q350 is approximately 642.6cm2 / 99.6inch2. The 706 S2 requires 6% less surface area than the Q350 which gives it a small advantage 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 B&W 706 S2 and KEF Q350 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 706 S2 weighs 8.05kg / 17.7lbs and the KEF Q350 weighs 7.60kg / 16.7lbs. This makes the 706 S2 6% heavier than the Q350.
Here is a comparison of how 706 S2 and Q350'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 706 S2?
Here are the items that are included inside the box of 706 S2:
2 Bookshelf loudspeakers2 Grilles2 Two-piece foam port plugs8 Self-adhesive rubber feet4 Jumper-straps Manual Bowers & Wilkins brochureWarranty Information
What's in the Box of KEF Q350?
Here are the items that come with the Q350:
2 Bookshelf loudspeakers 2 Foam port plugs 8 Self-adhesive rubber feet Owner's Manual Warranty Registration Card
 Sensitivity |
88 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
50 Hz
vs
63 Hz
|
Generates deeper bass |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Height |
340mm
vs
358mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
602cm2 (200x301mm)
vs
642cm2 (210x306mm)
|
Takes less floor space |
 Price per pair* |
750USD
vs
1999USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Bowers & Wilkins 706 S2 |
KEF Q350 |
| Brand |
Bowers Wilkins |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
30-120 watts |
10-120 watts |
| Sensitivity |
88 dB |
87 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.7 ohms |
3.7 ohms |
| Frequency Response |
50-28k Hz |
63-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Continuum |
Aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Decoupled Soft-Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
340.0mm (13.4") |
358.0mm (14.1") |
| Width |
200.0mm (7.9") |
210.0mm (8.3") |
| Depth |
301.0mm (11.9") |
306.0mm (12") |
| Weight |
8.05kg (17.7lbs) |
7.60kg (16.7lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Wood Veneer |
MDF/Vinyl-wrapped |
| Available Colors |
Rosewood, Gloss Black, Satin White |
Black, Walnut, White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
24-26" |
18-24" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |