In this review, we will be comparing ES15 and YU Passive 4-inch, two Passive Bookshelf speakers from Polk Audio and Kanto.
Let's have a brief look at the main features
of Polk ES15 and Kanto YU Passive 4-inch first before getting into our more
detailed comparison.
| Key Specs | Polk ES15 | Kanto YU Passive 4-inch |
|---|
| Brand | Polk Audio
United States · founded 1972 | Kanto
Canada · founded 2007 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Soft-Dome |
|---|
| Woofer | 5.25" Mica-reinforced polypropylene | 4" Kevlar |
|---|
| Frequency response | 44-40k Hz | 60-20k Hz |
|---|
| Sensitivity | 85 dB | 86 dB |
|---|
| Impedance | 8 ohms | 4 ohms |
|---|
| Power range | 20-100 watts | — |
|---|
| Weight | 5.91kg / 13lbs | 2.50kg / 5.5lbs |
|---|
| 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 | 8.7" x 5.5" x 7.5"
220.0 x 140.0 x 190.0mm |
|---|
What size room are the Polk ES15 and Kanto YU Passive 4-inch 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 |
Kanto YU Passive 4-inch |
| Near-field |
Average |
Good |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
No way |
(* 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.
Drivers
Both ES15 and YU Passive 4-inch are 2-way speakers.
Polk ES15Kanto YU Passive 4-inch
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 |
Kanto YU Passive 4-inch |
|
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 YU Passive 4-inch features a 1" Silk Soft-Dome Tweeter and 1 x 4" Kevlar Woofer.
Frequency Response
ES15 has a frequency range of 44-40k Hz whereas YU Passive 4-inch has a frequency range of 60-20k Hz. With a minimum frequency of 44Hz, the ES15 can go significantly deeper on the low side and provide stronger bass compared to the YU Passive 4-inch's min frequency of 60Hz.
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 YU Passive 4-inch which has a nominal impedance of 4 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the YU Passive 4-inch can provide this impedance level.
These two speakers also have different sensitivity levels. ES15 sensitivity is rated at 85 dB and the YU Passive 4-inch's is rated at 86 dB. This 1 dB difference makes the Kanto YU Passive 4-inch 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
ES15 features post type posts and YU Passive 4-inch has a post type posts. None of these speakers feature bi-amping/bi-wiring.
Polk ES15's 5-Way post terminals
Cabinet Type and Port Position
Both ES15 and YU Passive 4-inch 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 Kanto YU Passive 4-inch'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 Kanto YU Passive 4-inch has external dimensions of 220.0 x 140.0 x 190.0mm (8.7 x 5.5 x 7.5inch).
Polk ES15 is clearly the larger of the two speakers. Its body is 53mm wider, 87mm taller and 69mm deeper than Kanto YU Passive 4-inch.
Below you can see the front view size comparison of Polk ES15 and Kanto YU Passive 4-inch in scale.
Comparison image of Polk ES15 and Kanto YU Passive 4-inch 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 Kanto YU Passive 4-inch is approximately 266.0cm2 / 41.2inch2. The ES15 requires 88% more surface area than the YU Passive 4-inch 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 Kanto YU Passive 4-inch 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 Kanto YU Passive 4-inch weighs 2.50kg / 5.5lbs. This makes the ES15 136% heavier than the YU Passive 4-inch.
Here is a comparison of how ES15 and YU Passive 4-inch'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 Kanto YU Passive 4-inch?
Here are the items that come with the YU Passive 4-inch:
 Max Input Power |
100 watts
vs
70 watts
|
Handle more power from your amplifier |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Woofer Size |
5.25 inches
vs
4 inches
|
Larger woofer |
|
Low Frequency Response |
44 Hz
vs
60 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
20k Hz
|
Generates higher frequency |
 Mounting Bracket |
Yes
vs
No
|
Allows mounting on walls |
 Sensitivity |
86 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 Height |
220mm
vs
307mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
266cm2
vs
499cm2
|
Takes less floor space |
 Price per pair* |
200USD
vs
299USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Polk Audio Signature Elite ES15 |
Kanto YU Passive 4-inch |
| Brand |
Polk Audio |
Kanto |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Sensitivity |
85 dB |
86 dB |
| Impedance |
8 ohms |
4 ohms |
| Frequency Response |
44-40k Hz |
60-20k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
4" |
| Woofer Composition |
Mica-reinforced polypropylene |
Kevlar |
| Woofer Surround Material |
Butyl rubber |
n/a |
| 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") |
220.0mm (8.7") |
| Width |
193.0mm (7.6") |
140.0mm (5.5") |
| Depth |
259.0mm (10.2") |
190.0mm (7.5") |
| Weight |
5.91kg (13lbs) |
2.50kg (5.5lbs) |
| Enclosure |
Bass Reflex |
bass reflex |
| Finish |
MDF, Wood-grain vinyl |
n/a |
| Available Colors |
Black,White,Walnut |
Black,White |
| Mounting Bracket |
Keyhole |
No |
| Recommended Stand Height |
24-28" |
n/a |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
n/a |
Other |
|
|
| Parts Warranty |
5 Years |
2 years |
| Labor Warranty |
5 Years |
2 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 | A | Polk ES15 digs deeper - 44Hz against 60Hz. |
| 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; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | A | Polk ES15 takes more power (100W vs 70W) - more in hand in a big room. |
| Size | depends | Kanto YU Passive 4-inch 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 | B | Kanto YU Passive 4-inch is cheaper - $200 against $299, about 33% less. |
A Polk ES15 B Kanto YU Passive 4-inch
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?
The usual trade-off: Polk ES15 measures better, Kanto YU Passive 4-inch costs about about 50% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 60Hz anyway, which makes the cheaper Kanto YU Passive 4-inch much easier to justify. Match it to your room: we rate Kanto YU Passive 4-inch the better fit for near-field listening; elsewhere the two are rated the same.
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.