In this review, we will be comparing Demand D7 and Q150, two Passive Bookshelf speakers from Definitive Technology and KEF.
Let's have a brief look at the main features
of Definitive Demand D7 and KEF Q150 first before getting into our more
detailed comparison.
| Key Specs | Definitive Demand D7 | KEF Q150 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | — | 11th Generation Uni-Q |
|---|
| Tweeter | 1" Hard-Dome | 1" Dome |
|---|
| Woofer | 4.5" Polypropylene | 5.25" Aluminum |
|---|
| Frequency response | 67-21k Hz | 51-28k Hz |
|---|
| Sensitivity | 85 dB | 86 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 20-125 watts | 10-100 watts |
|---|
| Weight | 5.45kg / 12lbs | 5.60kg / 12.3lbs |
|---|
| Dimensions (H x W x D) | 9-7/8" x 5-9/16" x 9-1/8"
251.0 x 142.0 x 232.0mm | 11.9" x 7.0" x 10.9"
303.0 x 180.0 x 278.0mm |
|---|
What size room are the Definitive Demand D7 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:
| Listening Environment* |
Definitive Demand D7 |
KEF Q150 |
| Near-field |
Poor |
Average |
| Small Room |
Average |
Good |
| Mid-size Room |
Good |
Average |
| Large Room |
Average |
Poor |
| Very Large Room |
Poor |
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.
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through our links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both Demand D7 and Q150 are 2-way speakers.
Definitive Demand D7KEF Q150
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Definitive Demand D7 |
KEF Q150 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 4.5-inch
|
1 x 5.25-inch
|
Demand D7 features a 1" Hard-Dome Tweeter and 1 x 4.5" Polypropylene 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
Demand D7 has a frequency range of 67-21k Hz whereas Q150 has a frequency range of 51-28k Hz. With a minimum frequency of 51Hz, the Q150 can go significantly deeper on the low side and provide stronger bass compared to the Demand D7's min frequency of 67Hz.
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
Demand D7 and Q150 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Demand D7 sensitivity is rated at 85 dB and the Q150's is at 86 dB. This 1 dB difference makes the KEF Q150 a more sensitive speaker compared to Definitive Demand D7, 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.
Demand D7 can handle a max power of 125 watts RMS, whereas Q150 has a max power handling value of 100 watts RMS, 25 watts less than the Demand D7.
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
Demand D7 features Post type posts and Q150 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
Definitive Demand D7's 5-Way post terminals
KEF Q150's Post terminals
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 Definitive Demand D7's and KEF Q150's external dimensions. Definitive Demand D7 has external dimensions of 251.0 x 142.0 x 232.0mm (9-7/8 x 5-9/16 x 9-1/8inch) 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 38mm wider, 52mm taller and 46mm deeper than Definitive Demand D7.
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 Definitive Demand D7 is approximately 329.4cm2 / 51.1inch2 and base area of the KEF Q150 is approximately 500.4cm2 / 77.6inch2. The Demand D7 requires 34% less surface area than the Q150 which gives it a small advantage on placement in tight spaces.
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 Definitive Demand D7 weighs 5.45kg / 12lbs and the KEF Q150 weighs 5.60kg / 12.3lbs. This makes the Q150 3% heavier than the Demand D7.
Here is a comparison of how Demand D7 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 Definitive Demand D7?
Here are the items that are included inside the box of Demand D7:
- Left bookshelf loudpseaker
- Right bookshelf loudspeaker
- 2 Grilles
- Cleaning cloth
- Owners Manual
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
 Max Input Power |
125 watts
vs
100 watts
|
Handle more power from your amplifier |
 Height |
251mm
vs
303mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
329cm2
vs
500cm2
|
Takes less floor space |
 Price per pair* |
499USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
 Sensitivity |
86 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
5.25 inches
vs
4.5 inches
|
Larger woofer |
|
Low Frequency Response |
51 Hz
vs
67 Hz
|
Generates deeper bass |
 High Frequency Response |
28k Hz
vs
21k Hz
|
Generates higher frequency |
| General |
Definitive Technology Demand Series D7 |
KEF Q150 |
| Brand |
Definitive Technology |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-125 watts |
10-100 watts |
| Sensitivity |
85 dB |
86 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
n/a |
3.7 ohms |
| Frequency Response |
67-21k Hz |
51-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
4.5" |
5.25" |
| Woofer Composition |
Polypropylene |
Aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Hard-Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2500Hz |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
251.0mm (9.9") |
303.0mm (11.9") |
| Width |
142.0mm (5.6") |
180.0mm (7.1") |
| Depth |
232.0mm (9.1") |
278.0mm (10.9") |
| Weight |
5.45kg (12lbs) |
5.60kg (12.3lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Aluminum |
MDF/Vinyl-wrapped |
| Available Colors |
Gloss White,Piano Black |
Black, Walnut, White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
28-30" |
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 |
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 |
B |
KEF Q150 digs deeper - 51Hz against 67Hz. |
| Amplifier needs |
evenly matched |
Similar sensitivity (85dB vs 86dB) - both want much the same power. |
| Headroom |
A |
Definitive Demand D7 takes more power (125W vs 100W) - more in hand in a big room. |
| Size |
depends |
Definitive Demand D7 is easier to place; KEF Q150 is bigger, which usually goes with fuller bass. Your room decides. |
| Price |
A |
Definitive Demand D7 is cheaper - $499 against $600, about 17% less. |
A Definitive Demand D7
B KEF Q150
depends neither is better in the abstract - it turns on your room, placement 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 67Hz anyway, which makes the cheaper Definitive Demand D7 much easier to justify. Match it to your room: we rate Definitive Demand D7 the better fit for a mid-size room and a large room, and KEF Q150 for near-field listening and a small 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.