In this review, we will be comparing ES15 and Demand D7, two Passive Bookshelf speakers from Polk Audio and Definitive Technology.
Let's have a brief look at the main features
of Polk ES15 and Definitive Demand D7 first before getting into our more
detailed comparison.
| Key Specs | Polk ES15 | Definitive Demand D7 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Hard-Dome |
|---|
| Woofer | 5.25" Mica-reinforced polypropylene | 4.5" Polypropylene |
|---|
| Frequency response | 44-40k Hz | 67-21k Hz |
|---|
| Sensitivity | 85 dB | 85 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 20-100 watts | 20-125 watts |
|---|
| Weight | 5.91kg / 13lbs | 5.45kg / 12lbs |
|---|
| Dimensions (H x W x D) | 12-1/16" x 7-9/16" x 10-3/16"
307.0 x 193.0 x 259.0mm | 9-7/8" x 5-9/16" x 9-1/8"
251.0 x 142.0 x 232.0mm |
|---|
What size room are the Polk ES15 and Definitive Demand D7 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* |
Polk ES15 |
Definitive Demand D7 |
| 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.
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through our links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both ES15 and Demand D7 are 2-way speakers.
Polk ES15Definitive Demand D7
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Polk ES15 |
Definitive Demand D7 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 4.5-inch
|
ES15 features a 1" Terylene Soft-Dome Tweeter and 1 x 5.25" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz. On the other hand, the Demand D7 features a 1" Hard-Dome Tweeter and 1 x 4.5" Polypropylene Woofer.
Frequency Response
ES15 has a frequency range of 44-40k Hz whereas Demand D7 has a frequency range of 67-21k Hz. With a minimum frequency of 44Hz, the ES15 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
ES15 and Demand D7 have the same Impedance of 8 ohms and their sensitivity is also same at 85 dB.
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 ES15 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
ES15 features 5-Way post type posts and Demand D7 has a 5-Way post type posts. None of these speakers feature bi-amping/bi-wiring.
Polk ES15's 5-Way post terminals
Definitive Demand D7's 5-Way post terminals
Polk ES15 Power Port 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 Polk ES15's and Definitive Demand D7's external dimensions. Polk ES15 has external dimensions of 307.0 x 193.0 x 259.0mm (12-1/16 x 7-9/16 x 10-3/16inch) whereas 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).
Polk ES15 is clearly the larger of the two speakers. Its body is 51mm wider, 56mm taller and 27mm 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 Polk ES15 is approximately 499.9cm2 / 77.5inch2 and base area of the Definitive Demand D7 is approximately 329.4cm2 / 51.1inch2. The ES15 requires 52% more surface area than the Demand D7 which gives it a small disadvantage 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 Polk ES15 weighs 5.91kg / 13lbs and the Definitive Demand D7 weighs 5.45kg / 12lbs. This makes the ES15 8% heavier than the Demand D7.
Here is a comparison of how ES15 and Demand D7's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Polk ES15?
Here are the items that are included inside the box of ES15:
- 2 Bookshelf loudspeakers
- 2 Grille (attached)
- 8 Self-adhesive rubber feet
- Wall-mount template
- Owners Manual
- Online Product Registration
What's in the Box of Definitive Demand D7?
Here are the items that come with the Demand D7:
- Left bookshelf loudpseaker
- Right bookshelf loudspeaker
- 2 Grilles
- Cleaning cloth
- Owners Manual
 Woofer Size |
5.25 inches
vs
4.5 inches
|
Larger woofer |
|
Low Frequency Response |
44 Hz
vs
67 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
21k Hz
|
Generates higher frequency |
 Mounting Bracket |
Yes
vs
No
|
Allows mounting on walls |
 Price per pair* |
299USD
vs
499USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
125 watts
vs
100 watts
|
Handle more power from your amplifier |
 Height |
251mm
vs
307mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
329cm2
vs
499cm2
|
Takes less floor space |
| General |
Polk Audio Signature Elite ES15 |
Definitive Technology Demand Series D7 |
| Brand |
Polk Audio |
Definitive Technology |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-100 watts |
20-125 watts |
| Sensitivity |
85 dB |
85 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
44-40k Hz |
67-21k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
4.5" |
| Woofer Composition |
Mica-reinforced polypropylene |
Polypropylene |
| Woofer Surround Material |
Butyl rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
Hard-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
n/a |
| Firing Direction |
rear |
n/a |
Physical Specs |
|
|
| Height |
307.0mm (12.1") |
251.0mm (9.9") |
| Width |
193.0mm (7.6") |
142.0mm (5.6") |
| Depth |
259.0mm (10.2") |
232.0mm (9.1") |
| Weight |
5.91kg (13lbs) |
5.45kg (12lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF, Wood-grain vinyl |
MDF/Aluminum |
| Available Colors |
Black,White,Walnut |
Gloss White,Piano Black |
| Mounting Bracket |
Keyhole |
No |
| Recommended Stand Height |
24-28" |
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 |
These sit in different price classes - Definitive Demand D7 costs roughly 1.7x what Polk ES15 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 |
Polk ES15 digs deeper - 44Hz against 67Hz. |
| Amplifier needs |
evenly matched |
Similar sensitivity (85dB vs 85dB) - both want much the same power. |
| Headroom |
B |
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; Polk ES15 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability |
depends |
Neither adds bi-amping, a sub output or height drivers. Polk ES15 sits in a wider range (12 models), so a matched surround system is easier later. |
| Price |
A |
Polk ES15 is cheaper - $299 against $499, about 40% less; arguably a different class. |
A Polk ES15
B Definitive Demand D7
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, so judge these on the other rows instead. Match it to your room: we rate Polk ES15 the better fit for near-field listening and a small room, and Definitive Demand D7 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.