In this review, we will be comparing Q150 and RP-400M, two Passive Bookshelf speakers from KEF and Klipsch.
Let's have a brief look at the main features
of KEF Q150 and Klipsch RP-400M first before getting into our more
detailed comparison.
| Key Specs | KEF Q150 | Klipsch RP-400M |
|---|
| Brand | KEF
United Kingdom · founded 1961 | Klipsch
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | 11th Generation Uni-Q | — |
|---|
| Tweeter | 1" Dome | 1" Tractrix Horn |
|---|
| Woofer | 5.25" Aluminum | 4" Cerametallic |
|---|
| Frequency response | 51-28k Hz | 52-25k Hz |
|---|
| Sensitivity | 86 dB | 93 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 10-100 watts | up to 50 watts |
|---|
| Weight | 5.60kg / 12.3lbs | 4.10kg / 9lbs |
|---|
| Dimensions (H x W x D) | 11.9" x 7.0" x 10.9"
303.0 x 180.0 x 278.0mm | 11.7" x 5.6" x 7.5"
298.0 x 144.0 x 191.0mm |
|---|
What size room are the KEF Q150 and Klipsch RP-400M 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 |
Klipsch RP-400M |
| Near-field |
Average |
Good |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
No way |
(* 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 RP-400M are 2-way speakers.
KEF Q150Klipsch RP-400M
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 |
Klipsch RP-400M |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 4-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 RP-400M features a 1" Tractrix Horn Tweeter and 1 x 4" Cerametallic Woofer with a Crossover frequency at 1500Hz.
Frequency Response
Q150 has a frequency range of 51-28k Hz whereas RP-400M has a frequency range of 52-25k Hz. With a minimum frequency of 51Hz, the Q150 can go slightly deeper then the RP-400M's min frequency of 52Hz.
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 RP-400M have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Q150 sensitivity is rated at 86 dB and the RP-400M's is at 93 dB. This 7 dB difference makes the Klipsch RP-400M 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.
Q150 can handle a max power of 100 watts RMS, whereas RP-400M has a max power handling value of 50 watts RMS, 50 watts less than the Q150.
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 Single binding posts type posts and RP-400M has a Single binding posts type posts. None of these speakers feature bi-amping/bi-wiring.
KEF Q150's Post terminals
Klipsch RP-400M's Single binding posts terminals
Cabinet Type and Port Position
Both Q150 and RP-400M 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
Klipsch RP-400M Tractrix horn-shaped 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 Klipsch RP-400M'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 Klipsch RP-400M has external dimensions of 298.0 x 144.0 x 191.0mm (11.7 x 5.6 x 7.5inch).
KEF Q150 is clearly the larger of the two speakers. Its body is 36mm wider, 5mm taller and 87mm deeper than Klipsch RP-400M.
Below you can see the front view size comparison of KEF Q150 and Klipsch RP-400M in scale.
Comparison image of KEF Q150 and Klipsch RP-400M 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 Klipsch RP-400M is approximately 275.0cm2 / 42.6inch2. The Q150 requires 82% more surface area than the RP-400M 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 Klipsch RP-400M 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 Klipsch RP-400M weighs 4.10kg / 9lbs. This makes the Q150 37% heavier than the RP-400M.
Here is a comparison of how Q150 and RP-400M'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 Klipsch RP-400M?
Here are the items that come with the RP-400M:
- 2 Bookshelf loudspeakers
- 2 Grilles (installed)
- 8 Self-adhesive rubber feet
- User Manual
- Important Safety Instructions
- Warranty Information
 Max Input Power |
100 watts
vs
50 watts
|
Handle more power from your amplifier |
 Woofer Size |
5.25 inches
vs
4 inches
|
Larger woofer |
|
Low Frequency Response |
51 Hz
vs
52 Hz
|
Generates deeper bass |
 High Frequency Response |
28k Hz
vs
25k Hz
|
Generates higher frequency |
 Sensitivity |
93 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Mounting Bracket |
Yes
vs
No
|
Allows mounting on walls |
 Height |
298mm
vs
303mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
275cm2
vs
500cm2
|
Takes less floor space |
 Price per pair* |
399USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF Q150 |
Klipsch Reference Premiere RP-400M |
| Brand |
KEF |
Klipsch |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
10-100 watts |
up to 50 watts |
| Sensitivity |
86 dB |
93 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.7 ohms |
n/a |
| Frequency Response |
51-28k Hz |
52-25k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
4" |
| Woofer Composition |
Aluminum |
Cerametallic |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Tractrix Horn |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
1500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
303.0mm (11.9") |
298.0mm (11.7") |
| Width |
180.0mm (7.1") |
144.0mm (5.7") |
| Depth |
278.0mm (10.9") |
191.0mm (7.5") |
| Weight |
5.60kg (12.3lbs) |
4.10kg (9lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Vinyl-wrapped |
MDF/Wood-grain vinyl |
| Available Colors |
Black, Walnut, White |
Ebony, Walnut, Piano Black |
| Mounting Bracket |
No |
Keyhole |
| Recommended Stand Height |
18-24" |
28-30" |
| 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 |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (51Hz vs 52Hz). |
| Amplifier needs | B | Klipsch RP-400M is more sensitive (93dB vs 86dB), so it goes louder on the same amplifier. |
| Headroom | A | KEF Q150 takes more power (100W vs 50W) - more in hand in a big room. |
| Size | depends | Klipsch RP-400M is easier to place; KEF Q150 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Klipsch RP-400M sits in a wider range (17 models), so a matched surround system is easier later. |
| Price | B | Klipsch RP-400M is cheaper - $399 against $600, about 34% less. |
A KEF Q150 B Klipsch RP-400M
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. Match it to your room: we rate Klipsch RP-400M the better fit for near-field listening; elsewhere the two are rated the same. 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, Klipsch RP-400M 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.