In this review, we will be comparing S20 and ES20, two Passive Bookshelf speakers by Polk Audio.
Let's have a brief look at the main features
of Polk S20 and Polk ES20 first before getting into our more
detailed comparison.
| Key Specs | Polk S20 | Polk ES20 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Soft-Dome |
|---|
| Woofer | 6.5" Mica-reinforced polypropylene | 6.5" Mica-reinforced polypropylene |
|---|
| Frequency response | 39-40k Hz | 41-40k Hz |
|---|
| Sensitivity | 88 dB | 86 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 20-125 watts | 20-125 watts |
|---|
| Weight | 7.73kg / 17lbs | 7.73kg / 17lbs |
|---|
| Dimensions (H x W x D) | 14.8" x 8.5" x 13.7"
376.0 x 216.0 x 350.0mm | 14-3/4" x 8-9/16" x 13-13/16"
375.0 x 218.0 x 351.0mm |
|---|
What size room are the Polk S20 and Polk ES20 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 S20 |
Polk ES20 |
| 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.
**This post contains affiliate links, and we will be compensated if you make a purchase after clicking
through our links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both S20 and ES20 are 2-way speakers.
Polk S20Polk ES20
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 S20 |
Polk ES20 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 6.5-inch
|
S20 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 ES20 features a 1" Terylene Soft-Dome Tweeter and 1 x 6.5" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz.
Frequency Response
S20 has a frequency range of 39-40k Hz whereas ES20 has a frequency range of 41-40k Hz. With a minimum frequency of 39Hz, the S20 can go slightly deeper then the ES20's min frequency of 41Hz.
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
S20 and ES20 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. S20 sensitivity is rated at 88 dB and the ES20's is at 86 dB. This 2 dB difference makes the Polk S20 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.
S20 and ES20 have the same power range of 20-125 watts.
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
S20 features 5-Way post type posts and ES20 has a 5-Way post type posts. None of these speakers feature bi-amping/bi-wiring.
Cabinet Type and Port Position
Both S20 and ES20 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.
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 S20's and Polk ES20's external dimensions. Polk S20 has external dimensions of 376.0 x 216.0 x 350.0mm (14.8 x 8.5 x 13.7inch) whereas 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).
Polk S20 is 2mm narrower and 1mm less deeper than Polk ES20 but it is also 1mm taller.
Below you can see the front view size comparison of Polk S20 and Polk ES20 in scale.
Comparison image of Polk S20 and Polk ES20 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 S20 is approximately 756.0cm2 / 117.2inch2 and base area of the Polk ES20 is approximately 765.2cm2 / 118.6inch2. The S20 requires 1% less surface area than the ES20 which gives it a small advantage 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 S20 and Polk ES20 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 S20 weighs 7.73kg / 17lbs and the Polk ES20 weighs 7.73kg / 17lbs.
Here is a comparison of how S20 and ES20'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 S20?
Here are the items that are included inside the box of S20:
- 2 Bookshelf loudspeakers
- 2 Grilles (attached)
- 8 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
What's in the Box of Polk ES20?
Here are the items that come with the ES20:
- 2 Bookshelf loudspeakers
- 2 Grille (attached)
- 8 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
 Sensitivity |
88 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
39 Hz
vs
41 Hz
|
Generates deeper bass |
 Base Surface Area |
756cm2
vs
765cm2
|
Takes less floor space |
 Height |
375mm
vs
376mm
|
Easier to fit in smaller spaces |
| General |
Polk Audio Signature S20 |
Polk Audio Signature Elite ES20 |
| Brand |
Polk Audio |
Polk Audio |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-125 watts |
20-125 watts |
| Sensitivity |
88 dB |
86 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
39-40k Hz |
41-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Mica-reinforced polypropylene |
Mica-reinforced polypropylene |
| Woofer Surround Material |
Butyl rubber |
Butyl rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
376.0mm (14.8") |
375.0mm (14.8") |
| Width |
216.0mm (8.5") |
218.0mm (8.6") |
| Depth |
350.0mm (13.8") |
351.0mm (13.8") |
| Weight |
7.73kg (17lbs) |
7.73kg (17lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
Meddite MDF |
MDF, Wood-grain vinyl |
| Available Colors |
Black, Walnut, Brown Walnut |
Black,White,Walnut |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
24-28" |
22-26" |
| 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 |
A generation apart: Polk ES20 is the newer design, against a 2016 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass |
evenly matched |
Much the same reach (39Hz vs 41Hz). |
| Amplifier needs |
A |
Polk S20 is more sensitive (88dB vs 86dB), so it goes louder on the same amplifier. |
| Headroom |
evenly matched |
Similar power handling (125W vs 125W). |
| Size |
depends |
Similar cabinet size - neither is easier to fit. |
| Expandability |
depends |
Neither adds bi-amping, a sub output or height drivers. Polk ES20 sits in a wider range (12 models), so a matched surround system is easier later. |
A Polk S20
B Polk ES20
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?
Polk S20 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. If your amplifier is modest, vintage or valve-based, Polk S20 is the safer partner - the other will want more current or more watts to sound its best.
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.