In this review, we will be comparing S55 and RTi A9, two Passive Floor-standing speakers by Polk Audio Let's have a brief look at the main features
of Polk S55 and Polk RTi A9 first before getting into our more
detailed comparison.
What size room are the Polk S55 and Polk RTi A9 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 Polk S55 and Polk RTi A9 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
**This post contains affiliate links, and I will be compensated if you make a purchase after clicking
through my links. As an Amazon Associate I earn from qualifying purchases.
Drivers
One of the fundamental differences between these two speakers is that S55 is a 2-way design whereas the RTi A9 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.
Driver |
Polk S55 |
Polk RTi A9 |
Driver Setup
|
2-way
|
3-way
|
Tweeter
|
1-inch
|
1-inch
|
Midrange
|
- |
2 x 5.25-inch |
Woofer
|
2 x 6.5-inch
|
3 x 7-inch
|
S55 features a 1" Terylene Dome Tweeter and 2 x 6.5" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz. On the other hand, the RTi A9 features a 1" Tweeter , a 5.25" Midrange and 3 x 7" Polymer composite Woofer .
Frequency Response
S55 has a frequency range of 32-40k Hz whereas RTi A9 has a frequency range of 30-26k Hz. With a minimum frequency of 30Hz, the RTi A9 can go slightly deeper then the S55's min frequency of 32Hz.
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
S55 and RTi A9 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.
S55 can handle a max power of 500 watts RMS from the amp the whereas S55 has a max power handling value of 200 watts RMS , 300 watts less than the RTi A9.
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 S55 and RTi A9 features dual binding post speaker terminals for bi-amping or bi-wiring.
Cabinet Type and Port Position
S55 has a bottom firing port whereas RTi A9 has a front firing ports. Polk RTi A9's front-firing port gives more flexibility in placement in regards to proximity to walls compared to Polk S55 with its rear-firing 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 Polk S55's and Polk RTi A9's external dimensions. 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) whereas Polk RTi A9 has external dimensions of 1221.0 x 272.0 x 547.0mm ( 48-1/16 x 10-11/16 x 21-1/2inch) .
Polk S55 is 165mm shorter and 232mm less deeper than Polk RTi A9 but it is also 27mm wider.
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 S55 is approximately 941.9cm2 / 146.0inch2 and base area of the Polk RTi A9 is approximately 1487.8cm2 / 230.6inch2. The S55 requires 37% less surface area than the RTi A9 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 S55 weighs 20.00kg / 44lbs and the Polk RTi A9 weighs 34.09kg / 75lbs. This makes the RTi A9 70% heavier than the S55.
Here is a comparison of how S55 and RTi A9'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 S55?
Here are the items that are included inside the box of S55:
Floorstanding loudspeakerGrille (attached)4 Feet (pre-installed)Owners ManualOnline Product Registration
What's in the Box of Polk RTi A9?
Here are the items that come with the RTi A9:
Floor-standing speakerDetachable black cloth grille4 Screw-on spike feetOwners ManualOnline registration sheetPolk Audio product brochure
High Frequency Response |
40k Hz
vs
26k Hz
|
Generates higher frequency |
Height |
1056mm
vs
1221mm
|
Easier to fit in smaller spaces |
Base Surface Area |
941cm2 (299x315mm)
vs
1487cm2 (272x547mm)
|
Takes less floor space |
Max Input Power |
500 watts
vs
200 watts
|
Handle more power from your amplifier |
Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
Woofer Size |
7 inches
vs
6.5 inches
|
Larger woofer |
Number of Woofers |
3
vs
2
|
More woofers |
Low Frequency Response |
30 Hz
vs
32 Hz
|
Generates deeper bass |
General |
Polk Audio Signature S55 |
Polk Audio RTi A9 |
Brand |
Polk Audio |
Polk Audio |
Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
Power Range |
20-200 watts |
50-500 watts |
Sensitivity |
90 dB |
90 dB |
Impedance |
8 ohms |
8 ohms |
Frequency Response |
32-40k Hz |
30-26k Hz |
Drivers |
|
|
Woofer Quantity |
2 |
3 |
Woofer Size |
6.5" |
7" |
Woofer Composition |
Mica-reinforced polypropylene |
Polymer composite |
Woofer Surround Material |
Butyl rubber |
Butyl Rubber |
Tweeter Size |
1" |
1" |
Tweeter Type |
Dome |
n/a |
Aimable Tweeter |
No |
No |
Midrange Driver |
No |
5.25" |
Crossover Frequency |
2500Hz |
n/a |
Firing Direction |
bottom |
front |
Physical Specs |
|
|
Height |
1056.0mm (41.6") |
1221.0mm (48.1") |
Width |
299.0mm (11.8") |
272.0mm (10.7") |
Depth |
315.0mm (12.4") |
547.0mm (21.5") |
Weight |
20.00kg (44lbs) |
34.09kg (75lbs) |
Enclosure |
Bass Reflex |
Bass Reflex |
Finish |
Meddite MDF |
Real wood veneer |
Available Colors |
Black |
Cherry |
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 |