In this review, we will be comparing Q150 and Q350, two Passive Bookshelf speakers by KEF.
Let's have a brief look at the main features
of KEF Q150 and KEF Q350 first before getting into our more
detailed comparison.
| Key Specs | KEF Q150 | KEF Q350 |
|---|
| Brand | KEF
United Kingdom · founded 1961 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | 11th Generation Uni-Q | 11th Generation Uni-Q |
|---|
| Tweeter | 1" Dome | 1" Dome |
|---|
| Woofer | 5.25" Aluminum | 6.5" Aluminum |
|---|
| Frequency response | 51-28k Hz | 63-28k Hz |
|---|
| Sensitivity | 86 dB | 87 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 10-100 watts | 10-120 watts |
|---|
| Weight | 5.60kg / 12.3lbs | 7.60kg / 16.7lbs |
|---|
| Dimensions (H x W x D) | 11.9" x 7.0" x 10.9"
303.0 x 180.0 x 278.0mm | 14.0" x 8.2" x 12.0"
358.0 x 210.0 x 306.0mm |
|---|
Q150 and Q350 are members of KEF's Q series of speakers. Below you can find the loudspeakers from this series.
What size room are the KEF Q150 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:
| Listening Environment* |
KEF Q150 |
KEF Q350 |
| 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
Both Q150 and Q350 are 2-way speakers.
KEF Q150KEF Q350
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 |
KEF Q350 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 6.5-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 Q350 features a 1" vented aluminum Dome Tweeter and 1 x 6.5" Aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Q150 has a frequency range of 51-28k Hz whereas Q350 has a frequency range of 63-28k Hz. With a minimum frequency of 51Hz, the Q150 can go significantly deeper on the low side and provide stronger bass compared to the Q350's min frequency of 63Hz.
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 Q350 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Q150 sensitivity is rated at 86 dB and the Q350's is at 87 dB. This 1 dB difference makes the KEF Q350 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.
Q350 can handle a max power of 120 watts RMS, whereas Q150 has a max power handling value of 100 watts RMS, 20 watts less than the Q350.
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
Q150 features Post type posts and Q350 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
KEF Q150's Post terminals
KEF Q350's Post terminals
Cabinet Type and Port Position
Both Q150 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.
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 KEF Q350'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 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 30mm wider, 55mm taller and 28mm deeper than KEF Q150.
Below you can see the front view size comparison of KEF Q150 and KEF Q350 in scale.
Comparison image of KEF Q150 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 KEF Q150 is approximately 500.4cm2 / 77.6inch2 and base area of the KEF Q350 is approximately 642.6cm2 / 99.6inch2. The Q150 requires 22% less surface area than the Q350 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 KEF Q150 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 KEF Q150 weighs 5.60kg / 12.3lbs and the KEF Q350 weighs 7.60kg / 16.7lbs. This makes the Q350 36% heavier than the Q150.
Here is a comparison of how Q150 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 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 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
 Low Frequency Response |
51 Hz
vs
63 Hz
|
Generates deeper bass |
 Height |
303mm
vs
358mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
500cm2
vs
642cm2
|
Takes less floor space |
 Price per pair* |
600USD
vs
750USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
120 watts
vs
100 watts
|
Handle more power from your amplifier |
 Sensitivity |
87 dB
vs
86 dB
|
Play louder with same amount of amplification power |
|
Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
| General |
KEF Q150 |
KEF Q350 |
| Brand |
KEF |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
10-100 watts |
10-120 watts |
| Sensitivity |
86 dB |
87 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.7 ohms |
3.7 ohms |
| Frequency Response |
51-28k Hz |
63-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
6.5" |
| Woofer Composition |
Aluminum |
Aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
303.0mm (11.9") |
358.0mm (14.1") |
| Width |
180.0mm (7.1") |
210.0mm (8.3") |
| Depth |
278.0mm (10.9") |
306.0mm (12") |
| Weight |
5.60kg (12.3lbs) |
7.60kg (16.7lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Vinyl-wrapped |
MDF/Vinyl-wrapped |
| Available Colors |
Black, Walnut, White |
Black, Walnut, White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
18-24" |
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 |
Siblings in KEF's Q series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | A | KEF Q150 digs deeper - 51Hz against 63Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (86dB vs 87dB) - both want much the same power. |
| Headroom | evenly matched | Similar power handling (100W vs 120W). |
| Size | depends | KEF Q150 is easier to place; KEF Q350 is bigger, which usually goes with fuller bass. Your room decides. |
| Price | A | KEF Q150 is cheaper - $600 against $750, about 20% less. |
A KEF Q150 B KEF Q350
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 Q150 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 63Hz anyway, so judge these on the other rows instead. Match it to your room: we rate KEF Q150 the better fit for near-field listening and a small room, and KEF Q350 for a mid-size room and a large room.
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.