In this review, we will be comparing Reference R 50M and ES15, 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 ES15 first before getting into our more
detailed comparison.
| Key Specs | Klipsch Reference R 50M | Polk ES15 |
|---|
| 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" | 5.25" Mica-reinforced polypropylene |
|---|
| Frequency response | 58-21k Hz | 44-40k Hz |
|---|
| Sensitivity | 92 dB | 85 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | — | 20-100 watts |
|---|
| Weight | 4.99kg / 11lbs | 5.91kg / 13lbs |
|---|
| 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 | 12-1/16" x 7-9/16" x 10-3/16"
307.0 x 193.0 x 259.0mm |
|---|
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 ES15 are 2-way speakers.
Klipsch Reference R 50MPolk ES15
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 ES15 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 5.25-inch
|
Reference R 50M features a 1" Tractrix Horn Tweeter and 1 x 5.25" Woofer. On the other hand, the ES15 features a 1" Terylene Soft-Dome Tweeter and 1 x 5.25" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Reference R 50M has a frequency range of 58-21k Hz whereas ES15 has a frequency range of 44-40k Hz. With a minimum frequency of 44Hz, the ES15 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 ES15 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 ES15's is at 85 dB. This 7 dB difference makes the Klipsch Reference R 50M a more sensitive speaker compared to Polk ES15, 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 ES15 has a 5-Way post type posts. None of these speakers feature bi-amping/bi-wiring.
Polk ES15'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 Klipsch Reference R 50M's and Polk ES15's external dimensions. Klipsch Reference R 50M has external dimensions of 354.0 x 179.4 x 231.8mm () whereas 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).
Klipsch Reference R 50M is 13.6mm narrower and 27.2mm less deeper than Polk ES15 but it is also 47mm taller.
Below you can see the front view size comparison of Klipsch Reference R 50M and Polk ES15 in scale.
Comparison image of Klipsch Reference R 50M and Polk ES15 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 ES15 is approximately 499.9cm2 / 77.5inch2. The Reference R 50M requires 17% less surface area than the ES15 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 ES15 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 ES15 weighs 5.91kg / 13lbs. This makes the ES15 18% heavier than the Reference R 50M.
Here is a comparison of how Reference R 50M and ES15'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 come with the ES15:
- 2 Bookshelf loudspeakers
- 2 Grille (attached)
- 8 Self-adhesive rubber feet
- Wall-mount template
- Owners Manual
- Online Product Registration
 Sensitivity |
92 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 Base Surface Area |
415cm2
vs
499cm2
|
Takes less floor space |
 Low Frequency Response |
44 Hz
vs
58 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
21k Hz
|
Generates higher frequency |
 Height |
307mm
vs
354mm
|
Easier to fit in smaller spaces |
| General |
Klipsch Reference R 50M |
Polk Audio Signature Elite ES15 |
| Brand |
Klipsch |
Polk Audio |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Sensitivity |
92 dB |
85 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
58-21k Hz |
44-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
5.25" |
| 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") |
307.0mm (12.1") |
| Width |
179.4mm (7.1") |
193.0mm (7.6") |
| Depth |
231.8mm (9.1") |
259.0mm (10.2") |
| Weight |
4.99kg (11lbs) |
5.91kg (13lbs) |
| Enclosure |
|
Bass Reflex |
| Finish |
MDF/Wood-grain vinyl |
MDF, Wood-grain vinyl |
| Available Colors |
Black |
Black,White,Walnut |
| Mounting Bracket |
|
Keyhole |
| Recommended Stand Height |
n/a |
24-28" |
| 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 ES15 digs deeper - 44Hz against 58Hz. |
| Amplifier needs | A | Klipsch Reference R 50M is more sensitive (92dB vs 85dB), so it goes louder on the same amplifier. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| 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. |
A Klipsch Reference R 50M B Polk ES15
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. If your amplifier is modest, vintage or valve-based, Klipsch Reference R 50M 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.