In this review, we will be comparing Reference R 50M and ES20, two Passive Bookshelf speakers from Klipsch and Polk Audio.
Let's have a brief look at the main features
of Klipsch Reference R 50M and Polk ES20 first before getting into our more
detailed comparison.
| Key Specs | Klipsch Reference R 50M | Polk ES20 |
|---|
| Brand | Klipsch
United States · founded 1946 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Tractrix Horn | 1" Soft-Dome |
|---|
| Woofer | 5.25" | 6.5" Mica-reinforced polypropylene |
|---|
| Frequency response | 58-21k Hz | 41-40k Hz |
|---|
| Sensitivity | 92 dB | 86 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | — | 20-125 watts |
|---|
| Weight | 4.99kg / 11lbs | 7.73kg / 17lbs |
|---|
| Dimensions (H x W x D) | 13-15/16" x 7-1/16" x 9-1/8"
354.0 x 179.4 x 231.8mm | 14-3/4" x 8-9/16" x 13-13/16"
375.0 x 218.0 x 351.0mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Reference R 50M and ES20 are 2-way speakers.
Klipsch Reference R 50MPolk 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 |
Klipsch Reference R 50M |
Polk ES20 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 6.5-inch
|
Reference R 50M features a 1" Tractrix Horn Tweeter and 1 x 5.25" Woofer. 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
Reference R 50M has a frequency range of 58-21k Hz whereas ES20 has a frequency range of 41-40k Hz. With a minimum frequency of 41Hz, the ES20 can go significantly deeper on the low side and provide stronger bass compared to the Reference R 50M's min frequency of 58Hz.
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
Reference R 50M and ES20 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Reference R 50M sensitivity is rated at 92 dB and the ES20's is at 86 dB. This 6 dB difference makes the Klipsch Reference R 50M a more sensitive speaker compared to Polk ES20, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf Speakers
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
Reference R 50M features 5-Way post type posts and ES20 has a 5-Way post type posts. None of these speakers 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 Klipsch Reference R 50M's and Polk ES20's external dimensions. Klipsch Reference R 50M has external dimensions of 354.0 x 179.4 x 231.8mm () 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 ES20 is clearly the larger of the two speakers. Its body is 38.6mm wider, 21mm taller and 119.2mm deeper than Klipsch Reference R 50M.
Below you can see the front view size comparison of Klipsch Reference R 50M and Polk ES20 in scale.
Comparison image of Klipsch Reference R 50M 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 Klipsch Reference R 50M is approximately 415.8cm2 / 64.4inch2 and base area of the Polk ES20 is approximately 765.2cm2 / 118.6inch2. The Reference R 50M requires 46% 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 Klipsch Reference R 50M 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 Klipsch Reference R 50M weighs 4.99kg / 11lbs and the Polk ES20 weighs 7.73kg / 17lbs. This makes the ES20 55% heavier than the Reference R 50M.
Here is a comparison of how Reference R 50M 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 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 |
92 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Height |
354mm
vs
375mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
415cm2
vs
765cm2
|
Takes less floor space |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
41 Hz
vs
58 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
21k Hz
|
Generates higher frequency |
| General |
Klipsch Reference R 50M |
Polk Audio Signature Elite ES20 |
| Brand |
Klipsch |
Polk Audio |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Sensitivity |
92 dB |
86 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
58-21k Hz |
41-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
6.5" |
| Woofer Composition |
|
Mica-reinforced polypropylene |
| Woofer Surround Material |
n/a |
Butyl rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Tractrix Horn |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2500Hz |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
354.0mm (13.9") |
375.0mm (14.8") |
| Width |
179.4mm (7.1") |
218.0mm (8.6") |
| Depth |
231.8mm (9.1") |
351.0mm (13.8") |
| Weight |
4.99kg (11lbs) |
7.73kg (17lbs) |
| Enclosure |
|
Bass Reflex |
| Finish |
MDF/Wood-grain vinyl |
MDF, Wood-grain vinyl |
| Available Colors |
Black |
Black,White,Walnut |
| Mounting Bracket |
|
No |
| Recommended Stand Height |
n/a |
22-26" |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
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 | Polk ES20 digs deeper - 41Hz against 58Hz. |
| Amplifier needs | A | Klipsch Reference R 50M is more sensitive (92dB vs 86dB), so it goes louder on the same amplifier. |
| Size | depends | Klipsch Reference R 50M is easier to place; Polk ES20 is bigger, which usually goes with fuller bass. Your room decides. |
| 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 Klipsch Reference R 50M B Polk ES20
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 58Hz 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, Klipsch Reference R 50M 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.