In this review, we will be comparing ES15 and SS-CS5, two Passive Bookshelf speakers from Polk Audio and Sony.
Let's have a brief look at the main features
of Polk ES15 and Sony SS-CS5 first before getting into our more
detailed comparison.
| Key Specs | Polk ES15 | Sony SS-CS5 |
|---|
| Brand | Polk Audio
United States · founded 1972 | Sony
Japan · founded 1946 |
|---|
| Design | 2-way | 3-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Soft-Dome |
|---|
| Super tweeter | — | 0.75" super tweeter |
|---|
| Woofer | 5.25" Mica-reinforced polypropylene | 5.25" Mica Reinforced Cellular (MRC) |
|---|
| Frequency response | 44-40k Hz | 53-50k Hz |
|---|
| Sensitivity | 85 dB | 87 dB |
|---|
| Impedance | 8 ohms | 6 ohms |
|---|
| Power range | 20-100 watts | up to 100 watts |
|---|
| Weight | 5.91kg / 13lbs | 4.50kg / 9.9lbs |
|---|
| 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 | 13.1" x 7.0" x 8.6"
335.0 x 178.0 x 220.0mm |
|---|
What size room are the Polk ES15 and Sony SS-CS5 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 |
Sony SS-CS5 |
| Near-field |
Average |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
Bad |
(* 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
One of the fundamental differences between these two speakers is that ES15 is a 2-way design whereas the SS-CS5 is a 3-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
Polk ES15Sony SS-CS5
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 |
Sony SS-CS5 |
|
Driver Setup
|
2-way
|
3-way
|
|
Super Tweeter
|
- |
0.75-inch |
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 5.25-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 SS-CS5 features a 1" polyester fiber Soft-Dome Tweeter, a 0.75" Supertweeter and 1 x 5.25" Mica Reinforced Cellular (MRC) Woofer.
Frequency Response
ES15 has a frequency range of 44-40k Hz whereas SS-CS5 has a frequency range of 53-50k Hz. With a minimum frequency of 44Hz, the ES15 can go significantly deeper on the low side and provide stronger bass compared to the SS-CS5's min frequency of 53Hz.
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 is a 8 ohms speaker compared to the SS-CS5 which has a nominal impedance of 6 ohms.
These two speakers also have different sensitivity levels. ES15 sensitivity is rated at 85 dB and the SS-CS5's is rated at 87 dB. This 2 dB difference makes the Sony SS-CS5 a more sensitive speaker compared to Polk ES15, 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.
Both handle the same maximum of 100 watts RMS, though ES15 is rated 20-100 watts and SS-CS5 up to 100 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
ES15 features Post type posts and SS-CS5 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
Polk ES15's 5-Way post terminals
Sony SS-CS5's Post terminals
Cabinet Type and Port Position
Both ES15 and SS-CS5 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.
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 Sony SS-CS5'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 Sony SS-CS5 has external dimensions of 335.0 x 178.0 x 220.0mm (13.1 x 7.0 x 8.6inch).
Sony SS-CS5 is 15mm narrower and 39mm less deeper than Polk ES15 but it is also 28mm taller.
Below you can see the front view size comparison of Polk ES15 and Sony SS-CS5 in scale.
Comparison image of Polk ES15 and Sony SS-CS5 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 ES15 is approximately 499.9cm2 / 77.5inch2 and base area of the Sony SS-CS5 is approximately 391.6cm2 / 60.7inch2. The ES15 requires 28% more surface area than the SS-CS5 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 ES15 and Sony SS-CS5 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 ES15 weighs 5.91kg / 13lbs and the Sony SS-CS5 weighs 4.50kg / 9.9lbs. This makes the ES15 31% heavier than the SS-CS5.
Here is a comparison of how ES15 and SS-CS5'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
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 Low Frequency Response |
44 Hz
vs
53 Hz
|
Generates deeper bass |
 Mounting Bracket |
Yes
vs
No
|
Allows mounting on walls |
 Height |
307mm
vs
335mm
|
Easier to fit in smaller spaces |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Sensitivity |
87 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 High Frequency Response |
50k Hz
vs
40k Hz
|
Generates higher frequency |
 Base Surface Area |
391cm2
vs
499cm2
|
Takes less floor space |
 Price per pair* |
148USD
vs
299USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Polk Audio Signature Elite ES15 |
Sony SS-CS5 |
| Brand |
Polk Audio |
Sony |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-100 watts |
up to 100 watts |
| Sensitivity |
85 dB |
87 dB |
| Impedance |
8 ohms |
6 ohms |
| Frequency Response |
44-40k Hz |
53-50k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
5.25" |
| Woofer Composition |
Mica-reinforced polypropylene |
Mica Reinforced Cellular (MRC) |
| Woofer Surround Material |
Butyl rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
n/a |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
307.0mm (12.1") |
335.0mm (13.2") |
| Width |
193.0mm (7.6") |
178.0mm (7") |
| Depth |
259.0mm (10.2") |
220.0mm (8.7") |
| Weight |
5.91kg (13lbs) |
4.50kg (9.9lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF, Wood-grain vinyl |
MDF/Wood-veneer |
| Available Colors |
Black,White,Walnut |
Black |
| Mounting Bracket |
Keyhole |
No |
| Recommended Stand Height |
24-28" |
n/a |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Years |
2 years |
| Labor Warranty |
5 Years |
2 years |
These sit in different price classes - Polk ES15 costs roughly 2x what Sony SS-CS5 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 53Hz. A subwoofer would even that out. |
| Amplifier needs | B | Sony SS-CS5 is more sensitive (87dB vs 85dB), so it goes louder on the same amplifier. |
| Amplifier match | A | Polk ES15 is the easier load at 8 ohms. |
| Headroom | evenly matched | Similar power handling (100W vs 100W). |
| 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. |
| Price | B | Sony SS-CS5 is cheaper - $148 against $299, about 51% less; arguably a different class. |
A Polk ES15 B Sony SS-CS5
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?
Polk ES15 is ahead, but only on 1 of the measured areas, and it costs about 102% more. That is a lot of money for a narrow margin on paper - Sony SS-CS5 looks like the sensible buy unless something else about the Polk ES15 appeals to you. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 53Hz anyway, which makes the cheaper Sony SS-CS5 much easier to justify. If your amplifier is modest, vintage or valve-based, Sony SS-CS5 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.