In this review, we will be comparing Q150 and Crystal 4.2, two Passive Bookshelf speakers from KEF and Wharfedale.
Let's have a brief look at the main features
of KEF Q150 and Wharfedale Crystal 4.2 first before getting into our more
detailed comparison.
| Key Specs | KEF Q150 | Wharfedale Crystal 4.2 |
|---|
| Brand | KEF
United Kingdom · founded 1961 | Wharfedale
United Kingdom · founded 1932 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | 11th Generation Uni-Q | — |
|---|
| Tweeter | 1" Dome | 1" Soft-dome |
|---|
| Woofer | 5.25" Aluminum | 5" Woven Kevlar |
|---|
| Frequency response | 51-28k Hz | 60-20k Hz |
|---|
| Sensitivity | 86 dB | 88 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 10-100 watts | 20-100 watts |
|---|
| Weight | 5.60kg / 12.3lbs | 4.20kg / 9.2lbs |
|---|
| Dimensions (H x W x D) | 11.9" x 7.0" x 10.9"
303.0 x 180.0 x 278.0mm | 10-7/16" x 7-1/8" x 8-5/8"
266.0 x 181.0 x 220.0mm |
|---|
What size room are the KEF Q150 and Wharfedale Crystal 4.2 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* |
KEF Q150 |
Wharfedale Crystal 4.2 |
| 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 Q150 and Crystal 4.2 are 2-way speakers.
KEF Q150Wharfedale Crystal 4.2
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
KEF Q150 |
Wharfedale Crystal 4.2 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 5-inch
|
Q150 features a 1" vented aluminum Dome Tweeter and 1 x 5.25" Aluminum Woofer with a Crossover frequency at 2500Hz. On the other hand, the Crystal 4.2 features a 1" Soft-dome Tweeter and 1 x 5" Woven Kevlar Woofer.
Frequency Response
Q150 has a frequency range of 51-28k Hz whereas Crystal 4.2 has a frequency range of 60-20k Hz. With a minimum frequency of 51Hz, the Q150 can go significantly deeper on the low side and provide stronger bass compared to the Crystal 4.2's min frequency of 60Hz.
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
Q150 and Crystal 4.2 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Q150 sensitivity is rated at 86 dB and the Crystal 4.2's is at 88 dB. This 2 dB difference makes the Wharfedale Crystal 4.2 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. 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 Q150 is rated 10-100 watts and Crystal 4.2 20-100 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
Crystal 4.2 features 5-way post posts which make bi-amping or bi-wiring possible. Q150 has a Post which doesn't feature bi-amping/bi-wiring.
KEF Q150's Post terminals
Cabinet Type and Port Position
Both Q150 and Crystal 4.2 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 Q150 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 KEF Q150's and Wharfedale Crystal 4.2's external dimensions. KEF Q150 has external dimensions of 303.0 x 180.0 x 278.0mm (11.9 x 7.0 x 10.9inch) whereas Wharfedale Crystal 4.2 has external dimensions of 266.0 x 181.0 x 220.0mm (10-7/16 x 7-1/8 x 8-5/8inch).
Wharfedale Crystal 4.2 is 37mm shorter and 58mm less deeper than KEF Q150 but it is also 1mm wider.
Below you can see the front view size comparison of KEF Q150 and Wharfedale Crystal 4.2 in scale.
Comparison image of KEF Q150 and Wharfedale Crystal 4.2 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 Q150 is approximately 500.4cm2 / 77.6inch2 and base area of the Wharfedale Crystal 4.2 is approximately 398.2cm2 / 61.7inch2. The Q150 requires 26% more surface area than the Crystal 4.2 which gives it a small disadvantage 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 KEF Q150 and Wharfedale Crystal 4.2 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 Q150 weighs 5.60kg / 12.3lbs and the Wharfedale Crystal 4.2 weighs 4.20kg / 9.2lbs. This makes the Q150 33% heavier than the Crystal 4.2.
Here is a comparison of how Q150 and Crystal 4.2'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 Q150?
Here are the items that are included inside the box of Q150:
- 2 Bookshelf loudspeakers
- 2 Foam port plugs
- 8 Self-adhesive rubber feet
- Owner's Manual
- Warranty Registration Card
What's in the Box of Wharfedale Crystal 4.2?
Here are the items that come with the Crystal 4.2:
- 2 Bookshelf loudspeakers
- 2 Grilles (pre-installed)
- User-feets Manual
- Installation Guide
 Woofer Size |
5.25 inches
vs
5 inches
|
Larger woofer |
|
Low Frequency Response |
51 Hz
vs
60 Hz
|
Generates deeper bass |
 High Frequency Response |
28k Hz
vs
20k Hz
|
Generates higher frequency |
 Sensitivity |
88 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Height |
266mm
vs
303mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
398cm2
vs
500cm2
|
Takes less floor space |
 Price per pair* |
349USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF Q150 |
Wharfedale Crystal 4.2 |
| Brand |
KEF |
Wharfedale |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
10-100 watts |
20-100 watts |
| Sensitivity |
86 dB |
88 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.7 ohms |
n/a |
| Frequency Response |
51-28k Hz |
60-20k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
5" |
| Woofer Composition |
Aluminum |
Woven Kevlar |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Soft-dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
n/a |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
303.0mm (11.9") |
266.0mm (10.5") |
| Width |
180.0mm (7.1") |
181.0mm (7.1") |
| Depth |
278.0mm (10.9") |
220.0mm (8.7") |
| Weight |
5.60kg (12.3lbs) |
4.20kg (9.2lbs) |
| Enclosure |
Bass Reflex |
Bass reflex |
| Finish |
MDF/Vinyl-wrapped |
Wood-grain vinyl |
| Available Colors |
Black, Walnut, White |
Walnut |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
18-24" |
24-28" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
These sit in different price classes - KEF Q150 costs roughly 1.7x what Wharfedale Crystal 4.2 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 | KEF Q150 digs deeper - 51Hz against 60Hz. A subwoofer would even that out. |
| Amplifier needs | B | Wharfedale Crystal 4.2 is more sensitive (88dB vs 86dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (100W vs 100W). |
| Size | depends | Wharfedale Crystal 4.2 is easier to place; KEF Q150 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Wharfedale Crystal 4.2: bi-amping. KEF Q150 sits in a wider range (7 models), so a matched surround system is easier later. |
| Price | B | Wharfedale Crystal 4.2 is cheaper - $349 against $600, about 42% less; arguably a different class. |
A KEF Q150 B Wharfedale Crystal 4.2
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 60Hz anyway, which makes the cheaper Wharfedale Crystal 4.2 much easier to justify. In a large or open-plan room, KEF Q150 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Wharfedale Crystal 4.2 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.