In this review, we will be comparing XT15 and SS-CS5, two Passive Bookshelf speakers from Polk Audio and Sony.
Let's have a brief look at the main features
of Polk XT15 and Sony SS-CS5 first before getting into our more
detailed comparison.
| Key Specs | Polk XT15 | 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" Bi-laminate paper | 5.25" Mica Reinforced Cellular (MRC) |
|---|
| Frequency response | 48-40k Hz | 53-50k Hz |
|---|
| Sensitivity | 86 dB | 87 dB |
|---|
| Impedance | 8 ohms | 6 ohms |
|---|
| Power range | 30-150 watts | up to 100 watts |
|---|
| Weight | 4.09kg / 9lbs | 4.50kg / 9.9lbs |
|---|
| Dimensions (H x W x D) | 10-5/8" x 6-9/16" x 7-3/16"
270.0 x 167.0 x 183.0mm | 13.1" x 7.0" x 8.6"
335.0 x 178.0 x 220.0mm |
|---|
What size room are the Polk XT15 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 XT15 |
Sony SS-CS5 |
| Near-field |
Poor |
Average |
| Small Room |
Average |
Good |
| Mid-size Room |
Good |
Average |
| Large Room |
Average |
Poor |
| Very Large Room |
Poor |
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 XT15 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 XT15Sony 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 XT15 |
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
|
XT15 features a 1" Soft-Dome Tweeter and 1 x 5.25" Bi-laminate paper Woofer. 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
XT15 has a frequency range of 48-40k Hz whereas SS-CS5 has a frequency range of 53-50k Hz. With a minimum frequency of 48Hz, the XT15 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
XT15 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. XT15 sensitivity is rated at 86 dB and the SS-CS5's is rated at 87 dB. This 1 dB difference makes the Sony SS-CS5 a more sensitive speaker compared to Polk XT15, 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.
XT15 can handle a max power of 150 watts RMS, whereas SS-CS5 has a max power handling value of 100 watts RMS, 50 watts less than the XT15.
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
XT15 features Post type posts and SS-CS5 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
Sony SS-CS5's Post terminals
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 XT15's and Sony SS-CS5's external dimensions. Polk XT15 has external dimensions of 270.0 x 167.0 x 183.0mm (10-5/8 x 6-9/16 x 7-3/16inch) 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 clearly the larger of the two speakers. Its body is 11mm wider, 65mm taller and 37mm deeper than Polk XT15.
Below you can see the front view size comparison of Polk XT15 and Sony SS-CS5 in scale.
Comparison image of Polk XT15 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 XT15 is approximately 305.6cm2 / 47.4inch2 and base area of the Sony SS-CS5 is approximately 391.6cm2 / 60.7inch2. The XT15 requires 22% less surface area than the SS-CS5 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 Polk XT15 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 XT15 weighs 4.09kg / 9lbs and the Sony SS-CS5 weighs 4.50kg / 9.9lbs. This makes the SS-CS5 10% heavier than the XT15.
Here is a comparison of how XT15 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 XT15?
Here are the items that are included inside the box of XT15:
- 2 Bookshelf loudspeakers
- 2 Grilles (attached)
- 8 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
 Max Input Power |
150 watts
vs
100 watts
|
Handle more power from your amplifier |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 Low Frequency Response |
48 Hz
vs
53 Hz
|
Generates deeper bass |
 Height |
270mm
vs
335mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
305cm2
vs
391cm2
|
Takes less floor space |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Sensitivity |
87 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 High Frequency Response |
50k Hz
vs
40k Hz
|
Generates higher frequency |
 Price per pair* |
148USD
vs
199USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Polk Audio Monitor XT15 |
Sony SS-CS5 |
| Brand |
Polk Audio |
Sony |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
30-150 watts |
up to 100 watts |
| Sensitivity |
86 dB |
87 dB |
| Impedance |
8 ohms |
6 ohms |
| Frequency Response |
48-40k Hz |
53-50k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
5.25" |
| Woofer Composition |
Bi-laminate paper |
Mica Reinforced Cellular (MRC) |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
270.0mm (10.6") |
335.0mm (13.2") |
| Width |
167.0mm (6.6") |
178.0mm (7") |
| Depth |
183.0mm (7.2") |
220.0mm (8.7") |
| Weight |
4.09kg (9lbs) |
4.50kg (9.9lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF, Vinyl |
MDF/Wood-veneer |
| Available Colors |
Black |
Black |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
28-32" |
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 |
A generation apart: Polk XT15 is the newer design, against a 2014 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 XT15 digs deeper - 48Hz against 53Hz. A subwoofer would even that out. |
| Amplifier needs | evenly matched | Similar sensitivity (86dB vs 87dB) - both want much the same power. |
| Amplifier match | A | Polk XT15 is the easier load at 8 ohms. |
| Headroom | A | Polk XT15 takes more power (150W vs 100W) - more in hand in a big room. |
| Size | depends | Polk XT15 is easier to place; Sony SS-CS5 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Polk XT15 sits in a wider range (9 models), so a matched surround system is easier later. |
| Price | B | Sony SS-CS5 is cheaper - $148 against $199, about 26% less. |
A Polk XT15 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?
The usual trade-off: Polk XT15 measures better, Sony SS-CS5 costs about about 34% 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 53Hz anyway, which makes the cheaper Sony SS-CS5 much easier to justify. Match it to your room: we rate Polk XT15 the better fit for a mid-size room and a large room, and Sony SS-CS5 for near-field listening and a small room.
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.