In this review, we will be comparing ES15 and C 91 II, two Passive Bookshelf speakers from Polk Audio and Jamo.
Let's have a brief look at the main features
of Polk ES15 and Jamo C 91 II first before getting into our more
detailed comparison.
| Key Specs | Polk ES15 | Jamo C 91 II |
|---|
| Brand | Polk Audio
United States · founded 1972 | Jamo
Denmark · founded 1966 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Soft-Dome |
|---|
| Woofer | 5.25" Mica-reinforced polypropylene | 4" Composite |
|---|
| Frequency response | 44-40k Hz | 65-24k Hz |
|---|
| Sensitivity | 85 dB | 86 dB |
|---|
| Impedance | 8 ohms | 6 ohms |
|---|
| Power range | 20-100 watts | 50-100 watts |
|---|
| Weight | 5.91kg / 13lbs | 4.10kg / 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 | 10.4" x 6.7" x 7.5"
265.0 x 171.0 x 191.0mm |
|---|
What size room are the Polk ES15 and Jamo C 91 II 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 |
Jamo C 91 II |
| 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
Both ES15 and C 91 II are 2-way speakers.
Polk ES15Jamo C 91 II
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 |
Jamo C 91 II |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 4-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 C 91 II features a 1" Soft-Dome Tweeter and 1 x 4" Composite Woofer.
Frequency Response
ES15 has a frequency range of 44-40k Hz whereas C 91 II has a frequency range of 65-24k Hz. With a minimum frequency of 44Hz, the ES15 can go significantly deeper on the low side and provide stronger bass compared to the C 91 II's min frequency of 65Hz.
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 C 91 II 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 C 91 II's is rated at 86 dB. This 1 dB difference makes the Jamo C 91 II 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 C 91 II 50-100 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 5-way post type posts and C 91 II has a 5-way post type posts. None of these speakers feature bi-amping/bi-wiring.
Polk ES15's 5-Way post terminals
Jamo C 91 II's 5-way post terminals
Cabinet Type and Port Position
Both ES15 and C 91 II 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 Jamo C 91 II'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 Jamo C 91 II has external dimensions of 265.0 x 171.0 x 191.0mm (10.4 x 6.7 x 7.5inch).
Polk ES15 is clearly the larger of the two speakers. Its body is 22mm wider, 42mm taller and 68mm deeper than Jamo C 91 II.
Below you can see the front view size comparison of Polk ES15 and Jamo C 91 II in scale.
Comparison image of Polk ES15 and Jamo C 91 II 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 Jamo C 91 II is approximately 326.6cm2 / 50.6inch2. The ES15 requires 53% more surface area than the C 91 II 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 Jamo C 91 II 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 Jamo C 91 II weighs 4.10kg / 9lbs. This makes the ES15 44% heavier than the C 91 II.
Here is a comparison of how ES15 and C 91 II'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
What's in the Box of Jamo C 91 II?
Here are the items that come with the C 91 II:
- 2 Bookshelf loudspeakers
- 2 Grilles
- 8 Self-adhesive rubber feet
- 4 Self-adhesive rubber bumpers
- User Manual
- Important Safety Instructions Warranty Information
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 Woofer Size |
5.25 inches
vs
4 inches
|
Larger woofer |
|
Low Frequency Response |
44 Hz
vs
65 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
24k Hz
|
Generates higher frequency |
 Price per pair* |
299USD
vs
459USD
|
costs less (*prices may change depending on the seller, location and time) |
 Sensitivity |
86 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 Height |
265mm
vs
307mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
326cm2
vs
499cm2
|
Takes less floor space |
| General |
Polk Audio Signature Elite ES15 |
Jamo Concert 9 Series C 91 II |
| Brand |
Polk Audio |
Jamo |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-100 watts |
50-100 watts |
| Sensitivity |
85 dB |
86 dB |
| Impedance |
8 ohms |
6 ohms |
| Frequency Response |
44-40k Hz |
65-24k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
4" |
| Woofer Composition |
Mica-reinforced polypropylene |
Composite |
| 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") |
265.0mm (10.4") |
| Width |
193.0mm (7.6") |
171.0mm (6.7") |
| Depth |
259.0mm (10.2") |
191.0mm (7.5") |
| Weight |
5.91kg (13lbs) |
4.10kg (9lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF, Wood-grain vinyl |
MDF/Wood-grain |
| Available Colors |
Black,White,Walnut |
White Oak,Black Ash |
| Mounting Bracket |
Keyhole |
Keyhole |
| Recommended Stand Height |
24-28" |
28-32" |
| 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 ES15 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 | A | Polk ES15 digs deeper - 44Hz against 65Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (85dB vs 86dB) - both want much the same power. |
| Amplifier match | A | Polk ES15 is the easier load at 8 ohms. |
| Headroom | evenly matched | Similar power handling (100W vs 100W). |
| Size | depends | Jamo C 91 II is easier to place; Polk ES15 is bigger, which usually goes with fuller bass. Your room decides. |
| 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 | A | Polk ES15 is cheaper - $299 against $459, about 35% less. |
A Polk ES15 B Jamo C 91 II
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 the easier recommendation: it leads on most of the measured areas and costs less. Take Jamo C 91 II if its size, looks or fit in your room suit you better. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 65Hz anyway, so judge these on the other rows instead. In a large or open-plan room, Polk ES15 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Jamo C 91 II 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.