In this review, we will be comparing SX-50 and Q150, two Passive Bookshelf speakers from Cambridge Audio and KEF. Let's have a brief look at the main features
of Cambridge SX-50 and KEF Q150 first before getting into our more
detailed comparison.
What size room are the Cambridge SX-50 and KEF Q150 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 Cambridge SX-50 and KEF Q150 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 SX-50 and Q150 are 2-way speakers.
| Driver |
Cambridge SX-50 |
KEF Q150 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 5.25-inch
|
SX-50 features a 1" Silk Dome Tweeter and 1 x 5.25" Treated paper Woofer . On the other hand, the Q150 features a 1" vented aluminum Dome Tweeter and 1 x 5.25" Aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
SX-50 has a frequency range of 50-22k Hz whereas Q150 has a frequency range of 51-28k Hz. With a minimum frequency of 50Hz, the SX-50 can go slightly deeper then the Q150's min frequency of 51Hz.
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
SX-50 and Q150 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. SX-50 sensitivity is rated at 90 dB and the Q150's is at 86 dB. This 4 dB difference makes the Cambridge SX-50 a more sensitive speaker compared to KEF Q150, 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.
SX-50 and Q150 has the same power range of 10-100 watts.
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
SX-50 features Post type posts and Q150 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
Cambridge SX-50's 5-way post terminals
KEF Q150's Post terminals
Cabinet Type and Port Position
Both SX-50 and Q150 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.
Cambridge SX-50 Port
KEF Q150 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 Cambridge SX-50's and KEF Q150's external dimensions. Cambridge SX-50 has external dimensions of 225.0 x 161.0 x 240.0mm ( 8.8 x 6.3 x 9.4inch) whereas KEF Q150 has external dimensions of 303.0 x 180.0 x 278.0mm ( 11.9 x 7.0 x 10.9inch) .
KEF Q150 is clearly the larger of the two speakers. Its body is 19mm wider, 78mm taller and 38mm deeper than Cambridge SX-50.
Below you can see the front view size comparison of Cambridge SX-50 and KEF Q150 in scale.
Comparison image of Cambridge SX-50 and KEF Q150 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 Cambridge SX-50 is approximately 386.4cm2 / 59.9inch2 and base area of the KEF Q150 is approximately 500.4cm2 / 77.6inch2. The SX-50 requires 23% less surface area than the Q150 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 Cambridge SX-50 and KEF Q150 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 Cambridge SX-50 weighs 3.00kg / 6.6lbs and the KEF Q150 weighs 5.60kg / 12.3lbs. This makes the Q150 87% heavier than the SX-50.
Here is a comparison of how SX-50 and Q150's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Cambridge SX-50?
Here are the items that are included inside the box of SX-50:
2 Bookshelf loudspeakers 2 Grilles 8 Self-adhesive feet 2 Foam port inserts Installation Guide
What's in the Box of KEF Q150?
Here are the items that come with the Q150:
2 Bookshelf loudspeakers 2 Foam port plugs 8 Self-adhesive rubber feet Owner's Manual Warranty Registration Card
 Sensitivity |
90 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
50 Hz
vs
51 Hz
|
Generates deeper bass |
 Height |
225mm
vs
303mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
386cm2 (161x240mm)
vs
500cm2 (180x278mm)
|
Takes less floor space |
 Price per pair* |
199USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
 High Frequency Response |
28k Hz
vs
22k Hz
|
Generates higher frequency |
| General |
Cambridge Audio SX-50 |
KEF Q150 |
| Brand |
Cambridge Audio |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
10-100 watts |
10-100 watts |
| Sensitivity |
90 dB |
86 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
n/a |
3.7 ohms |
| Frequency Response |
50-22k Hz |
51-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
5.25" |
| Woofer Composition |
Treated paper |
Aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
225.0mm (8.9") |
303.0mm (11.9") |
| Width |
161.0mm (6.3") |
180.0mm (7.1") |
| Depth |
240.0mm (9.4") |
278.0mm (10.9") |
| Weight |
3.00kg (6.6lbs) |
5.60kg (12.3lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Woodgrain vinyl |
MDF/Vinyl-wrapped |
| Available Colors |
Black |
Black, Walnut, White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
28-31" |
18-24" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |