In this review, we will be comparing two different type of speakers by Definitive Technology. Definitive Technology Demand Series D7 is a Bookshelf speaker whereas the Demand D15 is a Floor-standing speaker.
Let's have a brief look at the main features
of Definitive Demand D7 and Definitive Demand D15 first before getting into our more
detailed comparison.
Definitive Demand D7 Key Specs
- 2-way Design
- 1" Hard-Dome Tweeter
- 4.5" Polypropylene Woofer
- 67-21k Hz Frequency Response
- 85 dB Sensitivity
- Impedance: 8ohms
- Power Range:20-125watts
- Weight:5.45kg
- Dimensions (H x W x D): 251.0" x 5-9/16" x 9-1/8"( 251.0 x 142.0 x 232.0mm )
Definitive Demand D15 Key Specs
- 3-way Design
- 1" dome Tweeter
- 5.25" Midrange
- 2 x 5.25" Carbon-fiber Woofer
- 5.25" Midrange
- 48-22k Hz Frequency Response
- 85.5 dB Sensitivity
- Impedance: 8ohms
- Power Range:30-300watts
- Weight:23.60kg
- Dimensions (H x W x D): 1023.0" x 9-1/16" x 12-3/4"( 1023.0 x 231.0 x 324.0mm )
Demand D7 and Demand D15 are members of Definitive Technology's Demand series of speakers. Below you can find the loudspeakers from this series.
Definitive Technology Demand Series History
What size room are the Definitive Demand D7 and Definitive Demand D15 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 |
Definitive Demand D15 |
| Near-field |
Poor |
Bad |
| Small Room |
Average |
Poor |
| Mid-size Room |
Good |
Average |
| Large Room |
Average |
Good |
| Very Large Room |
Poor |
Average |
(* 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.)
In the following sections, we will get into more detail in order to better understand how the Definitive Demand D7 and Definitive Demand D15 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
**This post contains affiliate links, and I will be compensated if you make a purchase after clicking
through my links. As an Amazon Associate I earn from qualifying purchases.
Drivers
One of the fundamental differences between these two speakers is that Demand D7 is a 2-way design whereas the Demand D15 is a 3-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
| Driver |
Definitive Demand D7 |
Definitive Demand D15 |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
1 x 5.25-inch |
|
Woofer
|
1 x 4.5-inch
|
2 x 5.25-inch
|
Demand D7 features a 1" Hard-Dome Tweeter and 1 x 4.5" Polypropylene Woofer . On the other hand, the Demand D15 features a 1" aluminum dome Tweeter , a 5.25" Midrange and 2 x 5.25" Carbon-fiber Woofer .
Frequency Response
Demand D7 has a frequency range of 67-21k Hz whereas Demand D15 has a frequency range of 48-22k Hz. With a minimum frequency of 48Hz, the Demand D15 can go significantly deeper on the low side and provide stronger bass compared to the Demand D7's min frequency of 67Hz.
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
Demand D7 and Demand D15 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 Demand D15's is at 85.5 dB. This 1 dB difference makes the Definitive Demand D15 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. 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.
Demand D7 can handle a max power of 300 watts RMS from the amp the whereas Demand D7 has a max power handling value of 125 watts RMS , 175 watts less than the Demand D15.
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
Demand D15 features 5-Way post posts which make bi-amping or bi-wiring possible. Demand D7 has a 5-Way post which doesn't feature bi-amping/bi-wiring.
Definitive Demand D7's 5-Way post terminals
Definitive Demand D15's 5-Way post terminals allows Bi-amping or bi-wiring
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 Definitive Demand D7's and Definitive Demand D15'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 Definitive Demand D15 has external dimensions of 1023.0 x 231.0 x 324.0mm ( 40-1/4 x 9-1/16 x 12-3/4inch) .
Definitive Demand D15 is clearly the larger of the two speakers. Its body is 89mm wider, 772mm taller and 92mm 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 Definitive Demand D15 is approximately 748.4cm2 / 116.0inch2. The Demand D7 requires 56% less surface area than the Demand D15 which gives it a small advantage on placement in tight spaces.
What's in the Box of Definitive Demand D7?
Here are the items that are included inside the box of Demand D7:
Left bookshelf loudpseakerRight bookshelf loudspeaker2 GrillesCleaning clothOwners Manual
What's in the Box of Definitive Demand D15?
Here are the items that come with the Demand D15:
Left floorstanding loudspeakerRight floorstanding loudspeaker2 Grilles4 Jumper-straps (pre-installed)2 Bases8 Spike feet8 Floor-glides8 Lock-rings8 ScrewsCleaning clothOwners Manual
Height 
Base Surface Area 
Price per pair* 
Max Input Power 
Driver Setup 
Sensitivity 
Woofer Size 
High Frequency Response 
Bi-Amping and Bi-Wiring 
Passive Radiator