In this review, we will be comparing Alpha T20 and S55, two Passive Floor-standing speakers from PSB and Polk Audio. Let's have a brief look at the main features
of PSB Alpha T20 and Polk S55 first before getting into our more
detailed comparison.
What size room are the PSB Alpha T20 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:
In the following sections, we will get into more detail in order to better understand how the PSB Alpha T20 and Polk S55 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
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through my links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both Alpha T20 and S55 are 2-way speakers.
| Driver |
PSB Alpha T20 |
Polk S55 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
0.75-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 5.25-inch
|
2 x 6.5-inch
|
Alpha T20 features a 0.75" anodized aluminum with front waveguide Dome Tweeter and 2 x 5.25" 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
Alpha T20 has a frequency range of 36-21k 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 Alpha T20's min frequency of 36Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing Speakers
High Frequency
Floor-standing Speakers
None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
Alpha T20 and S55 have the same Impedance of 8 ohms and their sensitivity is also same at 90 dB.
Sensitivity
Floor-standing Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. While using an amplifier within this range ensures the nominal performance , inputting a power that is higher than the max wattage can result in a damaged speaker.
Alpha T20 can handle a max power of 200 watts RMS from the amp the whereas Alpha T20 has a max power handling value of 120 watts RMS , 80 watts less than the S55.
Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker
compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters
such as Impedance, sensitivity and system efficiencies.
Input Type and Bi-Amping / Bi-Wiring
Both Alpha T20 and S55 features dual binding post speaker terminals for bi-amping or bi-wiring.
PSB Alpha T20'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
Alpha T20 has a rear firing port whereas S55 has a bottom firing ports. Polk S55's bottom-firing port gives more flexibility in placement in regards to proximity to walls compared to PSB Alpha T20 with its rear-firing port.
Polk S55 Port
Physical Specs
Size of a speaker can sometimes become an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare PSB Alpha T20's and Polk S55's external dimensions. PSB Alpha T20 has external dimensions of 869.0 x 212.0 x 250.0mm ( 34-3/16 x 8-5/16 x 9-13/16inch) 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 87mm wider, 187mm taller and 65mm deeper than PSB Alpha T20.
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 PSB Alpha T20 is approximately 530.0cm2 / 82.2inch2 and base area of the Polk S55 is approximately 941.9cm2 / 146.0inch2. The Alpha T20 requires 44% 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 PSB Alpha T20 weighs 11.89kg / 26.2lbs and the Polk S55 weighs 20.00kg / 44lbs. This makes the S55 68% heavier than the Alpha T20.
Here is a comparison of how Alpha T20 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 PSB Alpha T20?
Here are the items that are included inside the box of Alpha T20:
2 Floorstanding loudspeakers2 Grilles8 Rubber feet8 Spike feet8 Hex-nutsQuick Start GuideWarranty Card
What's in the Box of Polk S55?
Here are the items that come with the S55:
Floorstanding loudspeakerGrille (attached)4 Feet (pre-installed)Owners ManualOnline Product Registration
 Height |
869mm
vs
1056mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
530cm2 (212x250mm)
vs
941cm2 (299x315mm)
|
Takes less floor space |
 Max Input Power |
200 watts
vs
120 watts
|
Handle more power from your amplifier |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
| Low Frequency Response |
32 Hz
vs
36 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
21k Hz
|
Generates higher frequency |
 Price per pair* |
658USD
vs
799USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
PSB Alpha T20 |
Polk Audio Signature S55 |
| Brand |
PSB |
Polk Audio |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
15-120 watts |
20-200 watts |
| Sensitivity |
90 dB |
90 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
36-21k Hz |
32-40k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5.25" |
6.5" |
| Woofer Composition |
Polypropylene |
Mica-reinforced polypropylene |
| Woofer Surround Material |
Rubber |
Butyl rubber |
| Tweeter Size |
0.75" |
1" |
| Tweeter Type |
Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
2500Hz |
| Firing Direction |
rear |
bottom |
Physical Specs |
|
|
| Height |
869.0mm (34.2") |
1056.0mm (41.6") |
| Width |
212.0mm (8.3") |
299.0mm (11.8") |
| Depth |
250.0mm (9.8") |
315.0mm (12.4") |
| Weight |
11.89kg (26.2lbs) |
20.00kg (44lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF, Wood-grain vinyl |
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 |