In this review, we will be comparing S50 and S55, two Passive Floor-standing speakers by Polk Audio.
Let's have a brief look at the main features
of Polk S50 and Polk S55 first before getting into our more
detailed comparison.
| Key Specs | Polk S50 | Polk S55 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Dome | 1" Dome |
|---|
| Woofer | 2 x 5.25" Mica-reinforced polypropylene | 2 x 6.5" Mica-reinforced polypropylene |
|---|
| Frequency response | 33-40k Hz | 32-40k Hz |
|---|
| Sensitivity | 89 dB | 90 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 20-150 watts | 20-200 watts |
|---|
| Weight | 14.50kg / 31.9lbs | 20.00kg / 44lbs |
|---|
| Dimensions (H x W x D) | 37-7/16" x 10-5/16" x 11-1/16"
951.0 x 262.0 x 281.0mm | 41-9/16" x 11-3/4" x 12-3/8"
1056.0 x 299.0 x 315.0mm |
|---|
S50 and S55 are members of Polk Audio's Signature S series of speakers. Below you can find the loudspeakers from this series.
What size room are the Polk S50 and Polk S55 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 S50 |
Polk S55 |
| Near-field |
Bad |
Bad |
| Small Room |
Poor |
Poor |
| Mid-size Room |
Good |
Good |
| Large Room |
Good |
Good |
| Very Large Room |
Poor |
Poor |
(* 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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Drivers
Both S50 and S55 are 2-way speakers.
Polk S50Polk S55
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 S50 |
Polk S55 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 5.25-inch
|
2 x 6.5-inch
|
S50 features a 1" Terylene Dome Tweeter and 2 x 5.25" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz. On the other hand, the S55 features a 1" Terylene Dome Tweeter and 2 x 6.5" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz.
Frequency Response
S50 has a frequency range of 33-40k Hz whereas S55 has a frequency range of 32-40k Hz. With a minimum frequency of 32Hz, the S55 can go slightly deeper then the S50's min frequency of 33Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing 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
S50 and S55 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. S50 sensitivity is rated at 89 dB and the S55's is at 90 dB. This 1 dB difference makes the Polk S55 a more sensitive speaker compared to Polk S50, hence will play louder with the same amount of watts.
Sensitivity
Floor-standing 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.
S55 can handle a max power of 200 watts RMS, whereas S50 has a max power handling value of 150 watts RMS, 50 watts less than the S55.
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
Both S50 and S55 features dual binding post speaker terminals for bi-amping or bi-wiring.
Polk S50's 5-way post terminals allows Bi-amping or bi-wiring
Polk S55's 5-way post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both S50 and S55 have bottom firing ports.
Polk S50 Port
Polk S55 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 S50's and Polk S55's external dimensions. Polk S50 has external dimensions of 951.0 x 262.0 x 281.0mm (37-7/16 x 10-5/16 x 11-1/16inch) whereas Polk S55 has external dimensions of 1056.0 x 299.0 x 315.0mm (41-9/16 x 11-3/4 x 12-3/8inch).
Polk S55 is clearly the larger of the two speakers. Its body is 37mm wider, 105mm taller and 34mm deeper than Polk S50.
Below you can see the front view size comparison of Polk S50 and Polk S55 in scale.
Comparison image of Polk S50 and Polk S55 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 S50 is approximately 736.2cm2 / 114.1inch2 and base area of the Polk S55 is approximately 941.9cm2 / 146.0inch2. The S50 requires 22% less surface area than the S55 which gives it a small advantage on placement in tight spaces.
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 S50 weighs 14.50kg / 31.9lbs and the Polk S55 weighs 20.00kg / 44lbs. This makes the S55 38% heavier than the S50.
Here is a comparison of how S50 and S55's weights compare with the average, max and min weights in Passive Floor-standing class.
Weight
All Floor-standing Speakers
What's in the Box of Polk S50?
Here are the items that are included inside the box of S50:
- Floorstanding loudspeaker
- Grille (attached)
- 4 Feet (pre-installed)
- Owners Manual
- Online Product Registration
What's in the Box of Polk S55?
Here are the items that come with the S55:
- Floorstanding loudspeaker
- Grille (attached)
- 4 Feet (pre-installed)
- Owners Manual
- Online Product Registration
 Height |
951mm
vs
1056mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
736cm2
vs
941cm2
|
Takes less floor space |
 Max Input Power |
200 watts
vs
150 watts
|
Handle more power from your amplifier |
 Sensitivity |
90 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
32 Hz
vs
33 Hz
|
Generates deeper bass |
| General |
Polk Audio Signature S50 |
Polk Audio Signature S55 |
| Brand |
Polk Audio |
Polk Audio |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
20-150 watts |
20-200 watts |
| Sensitivity |
89 dB |
90 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
33-40k Hz |
32-40k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5.25" |
6.5" |
| Woofer Composition |
Mica-reinforced polypropylene |
Mica-reinforced polypropylene |
| Woofer Surround Material |
Butyl rubber |
Butyl rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
2500Hz |
| Firing Direction |
bottom |
bottom |
Physical Specs |
|
|
| Height |
951.0mm (37.4") |
1056.0mm (41.6") |
| Width |
262.0mm (10.3") |
299.0mm (11.8") |
| Depth |
281.0mm (11.1") |
315.0mm (12.4") |
| Weight |
14.50kg (31.9lbs) |
20.00kg (44lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
Meddite MDF |
Meddite MDF |
| Available Colors |
Black |
Black |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
Siblings in Polk Audio's Signature S series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass |
evenly matched |
Much the same reach (33Hz vs 32Hz). |
| Amplifier needs |
evenly matched |
Similar sensitivity (89dB vs 90dB) - both want much the same power. |
| Headroom |
B |
Polk S55 takes more power (200W vs 150W) - more in hand in a big room. |
| Size |
depends |
Polk S50 is easier to place; Polk S55 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability |
depends |
Polk S50: bi-amping; Polk S55: bi-amping. |
A Polk S50
B Polk S55
depends neither is better in the abstract - it turns on your room, placement 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 S55 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. In a large or open-plan room, Polk S55 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Polk S50 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.