In this review, we will be comparing ES20 and Demand D9, two Passive Bookshelf speakers from Polk Audio and Definitive Technology.
Let's have a brief look at the main features
of Polk ES20 and Definitive Demand D9 first before getting into our more
detailed comparison.
| Key Specs | Polk ES20 | Definitive Demand D9 |
|---|
| Brand | Polk Audio
United States · founded 1972 | Definitive Technology
United States · founded 1990 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Hard-Dome |
|---|
| Woofer | 6.5" Mica-reinforced polypropylene | 5.25" Polypropylene |
|---|
| Frequency response | 41-40k Hz | 64-22k Hz |
|---|
| Sensitivity | 86 dB | 88 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 20-125 watts | 20-150 watts |
|---|
| Weight | 7.73kg / 17lbs | 7.73kg / 17lbs |
|---|
| Dimensions (H x W x D) | 14-3/4" x 8-9/16" x 13-13/16"
375.0 x 218.0 x 351.0mm | 11-13/16" x 6-9/16" x 12-7/16"
301.0 x 167.0 x 316.0mm |
|---|
What size room are the Polk ES20 and Definitive Demand D9 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 ES20 |
Definitive Demand D9 |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
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 ES20 and Demand D9 are 2-way speakers.
Polk ES20Definitive Demand D9
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 ES20 |
Definitive Demand D9 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 5.25-inch
|
ES20 features a 1" Terylene Soft-Dome Tweeter and 1 x 6.5" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz. On the other hand, the Demand D9 features a 1" Hard-Dome Tweeter and 1 x 5.25" Polypropylene Woofer.
Frequency Response
ES20 has a frequency range of 41-40k Hz whereas Demand D9 has a frequency range of 64-22k Hz. With a minimum frequency of 41Hz, the ES20 can go significantly deeper on the low side and provide stronger bass compared to the Demand D9's min frequency of 64Hz.
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
ES20 and Demand D9 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. ES20 sensitivity is rated at 86 dB and the Demand D9's is at 88 dB. This 2 dB difference makes the Definitive Demand D9 a more sensitive speaker compared to Polk ES20, 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 D9 can handle a max power of 150 watts RMS, whereas ES20 has a max power handling value of 125 watts RMS, 25 watts less than the Demand D9.
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 D9 features 5-Way post posts which make bi-amping or bi-wiring possible. ES20 has a 5-Way post which doesn't feature bi-amping/bi-wiring.
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 ES20's and Definitive Demand D9's external dimensions. Polk ES20 has external dimensions of 375.0 x 218.0 x 351.0mm (14-3/4 x 8-9/16 x 13-13/16inch) whereas Definitive Demand D9 has external dimensions of 301.0 x 167.0 x 316.0mm (11-13/16 x 6-9/16 x 12-7/16inch).
Polk ES20 is clearly the larger of the two speakers. Its body is 51mm wider, 74mm taller and 35mm deeper than Definitive Demand D9.
Below you can see the front view size comparison of Polk ES20 and Definitive Demand D9 in scale.
Comparison image of Polk ES20 and Definitive Demand D9 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 Polk ES20 is approximately 765.2cm2 / 118.6inch2 and base area of the Definitive Demand D9 is approximately 527.7cm2 / 81.8inch2. The ES20 requires 45% more surface area than the Demand D9 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 Polk ES20 and Definitive Demand D9 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 Polk ES20 weighs 7.73kg / 17lbs and the Definitive Demand D9 weighs 7.73kg / 17lbs.
Here is a comparison of how ES20 and Demand D9'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 ES20?
Here are the items that are included inside the box of ES20:
- 2 Bookshelf loudspeakers
- 2 Grille (attached)
- 8 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
What's in the Box of Definitive Demand D9?
Here are the items that come with the Demand D9:
- Left bookshelf loudpseaker
- Right bookshelf loudspeaker
- 2 Grilles
- 4 Jumper-straps (pre-installed)
- Cleaning cloth
- Owners Manual
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
41 Hz
vs
64 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
22k Hz
|
Generates higher frequency |
 Price per pair* |
399USD
vs
749USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
150 watts
vs
125 watts
|
Handle more power from your amplifier |
 Sensitivity |
88 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Height |
301mm
vs
375mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
527cm2
vs
765cm2
|
Takes less floor space |
| General |
Polk Audio Signature Elite ES20 |
Definitive Technology Demand Series D9 |
| Brand |
Polk Audio |
Definitive Technology |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-125 watts |
20-150 watts |
| Sensitivity |
86 dB |
88 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
41-40k Hz |
64-22k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
5.25" |
| 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 |
375.0mm (14.8") |
301.0mm (11.9") |
| Width |
218.0mm (8.6") |
167.0mm (6.6") |
| Depth |
351.0mm (13.8") |
316.0mm (12.4") |
| Weight |
7.73kg (17lbs) |
7.73kg (17lbs) |
| Enclosure |
Bass Reflex |
Passive Radiator |
| Finish |
MDF, Wood-grain vinyl |
MDF/Aluminum |
| Available Colors |
Black,White,Walnut |
Gloss White,Piano Black |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
22-26" |
24-28" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
These sit in different price classes - Definitive Demand D9 costs roughly 1.9x what Polk ES20 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 ES20 digs deeper - 41Hz against 64Hz. |
| Amplifier needs | B | Definitive Demand D9 is more sensitive (88dB vs 86dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (125W vs 150W). |
| Size | depends | Definitive Demand D9 is easier to place; Polk ES20 is bigger, which usually goes with fuller bass. Your room decides. |
| Cabinet | depends | Ported vs Passive Radiator. |
| Expandability | depends | Definitive Demand D9: bi-amping. Polk ES20 sits in a wider range (12 models), so a matched surround system is easier later. |
| Price | A | Polk ES20 is cheaper - $399 against $749, about 47% less; arguably a different class. |
A Polk ES20 B Definitive Demand D9
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. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 64Hz anyway, so judge these on the other rows instead. In a large or open-plan room, Polk ES20 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Definitive Demand D9 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.