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Polk Audio RC85i vs Polk Audio RC55i Comparison

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Polk Audio RC85i

Passive In-wall | 50-20kHz

Polk Audio RC85i
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Polk Audio RC55i

Passive In-wall | 70-20kHz

Polk Audio RC55i
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Polk Audio RC85i Polk Audio RC85i
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Polk Audio RC55i Polk Audio RC55i
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Polk Audio RC85i
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Polk Audio RC55i
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Polk Audio RC85i vs Polk Audio RC55i Speaker Comparison

In this review, we will be comparing RC85i and RC55i, two Passive In-wall speakers by Polk Audio

Let's have a brief look at the main features of Polk Audio RC85i and Polk Audio RC55i first before getting into our more detailed comparison.

Polk Audio RC85i Key Specs

  • 2-way Design
  • 1" Hard-Dome Tweeter
  • 8" Polypropylene Woofer
  • 50-20kHz Frequency Response
  • 90 dB Sensitivity
  • Impedance: 8ohms
  • Power Range:20-100watts
  • Dimensions (H x W x D): 324.0" x 8.6875" x 3.5000"( 324.0 x 221.0 x 89.0mm )

Polk Audio RC55i Key Specs

  • 2-way Design
  • 0.75" Hard-Dome Tweeter
  • 5.25" Polypropylene Woofer
  • 70-20kHz Frequency Response
  • 89 dB Sensitivity
  • Impedance: 8ohms
  • Power Range:20-100watts
  • Dimensions (H x W x D): 245.0" x 6.1875" x 2.0120"( 245.0 x 158.0 x 52.0mm )

What size room are the Polk Audio RC85i and Polk Audio RC55i 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 Audio RC85i Polk Audio RC55i
Near-field Average Average
Small Room Good Good
Mid-size Room Average Average
Large Room Poor Poor
Very Large Room Bad 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.)

In the following sections, we will get into more detail in order to better understand how the Polk Audio RC85i and Polk Audio RC55i 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

Both RC85i and RC55i are 2-way speakers.

Driver Polk Audio RC85i Polk Audio RC55i
Driver Setup 2-way 2-way
Tweeter 1-inch 0.75-inch
Midrange - -
Woofer 1 x 8-inch 1 x 5.25-inch

RC85i features a 1" Hard-Dome Tweeter and 1 x 8" Polypropylene Woofer . On the other hand, the RC55i features a 0.75" Hard-Dome Tweeter and 1 x 5.25" Polypropylene Woofer .

Frequency Response

RC85i has a frequency range of 50-20kHz whereas RC55i has a frequency range of 70-20kHz. With a minimum frequency of 50Hz, the RC85i can go significantly deeper on the low side and provide stronger bass compared to the RC55i's min frequency of 70Hz.

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 In-wall class in our database.

Low Frequency

In-wall Speakers

RC85i
RC55i
Min
Average
Max
High Frequency

In-wall Speakers

Polk Audio RC85i
Polk Audio RC55i
Min
Average
Max

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

RC85i and RC55i have the same Impedance of 8 ohms but where they differ is the sensitivity levels. RC85i sensitivity is rated at 90 dB and the RC55i's is at 89 dB. This 1 dB difference makes the Polk Audio RC85i a more sensitive speaker compared to Polk Audio RC55i, hence will play louder with the same amount of watts.

Sensitivity

In-wall Speakers

RC85i
RC55i
Min
Average
Max

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.

RC85i and RC55i has the same power range of 20-100 watts.

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

RC85i features Spring clip type posts and RC55i has a Spring clip type posts. None of these speakers feature bi-amping/bi-wiring.

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 Audio RC85i's and Polk Audio RC55i's external dimensions. Polk Audio RC85i has external dimensions of 324.0 x 221.0 x 89.0mm ( 12.7500-inch x 8.6875-inch x 3.5000-inch) whereas Polk Audio RC55i has external dimensions of 245.0 x 158.0 x 52.0mm ( 9.6250-inch x 6.1875-inch x 2.0120-inch) .

Polk Audio RC85i is clearly the larger of the two speakers. Its body is 63mm wider, 79mm taller and 37mm deeper than Polk Audio RC55i.

What's in the Box of Polk Audio RC85i?

Here are the items that are included inside the box of RC85i:
  • 2 White in-wall speakers
  • 2 White grilles
  • 1 Cardboard Mounting Template
  • Owners Manual
  • Online registration sheet
  • Product Registration Card
  • What's in the Box of Polk Audio RC55i?

    Here are the items that come with the RC55i:
  • 2 White in-wall speakers
  • 2 White grilles
  • 1 Cardboard Mounting Template
  • Owners Manual
  • Online registration sheet
  • Product Registration Card

  • Reasons to choose Polk Audio RC85i over Polk Audio RC55i
    Sensitivity 90 dB vs 89 dB Play louder with same amount of amplification power
    Woofer Size 8 inches vs 5.25 inches Larger woofer
    Low Frequency Response 50 Hz vs 70 Hz Generates deeper bass

    Reasons to choose Polk Audio RC55i over Polk Audio RC85i

    Height 245mm vs 324mm Easier to fit in smaller spaces
    Base Surface Area 82cm2 vs 196cm2 Takes less floor space
    Price per pair* 129USD vs 279USD costs less (*prices may change depending on the seller, location and time)
    Polk Audio RC85i vs Polk Audio RC55i Specs Table
    Detailed comparison of specifications
    General Polk Audio RC85i Polk Audio RC55i
    Brand Polk Audio Polk Audio
    Speaker Type Passive In-wall Speaker Passive In-wall Speaker
    Power Range 20-100 watts 20-100 watts
    Sensitivity 90 dB 89 dB
    Impedance 8 ohms 8 ohms
    Frequency Response 50-20kHz 70-20kHz
    Drivers
    Woofer Quantity 1 1
    Woofer Size 8" 5.25"
    Woofer Composition Polypropylene Polypropylene
    Woofer Surround Material Rubber Rubber
    Tweeter Size 1" 0.75"
    Tweeter Type Hard-Dome Hard-Dome
    Aimable Tweeter Yes Yes
    Midrange Driver N/A" N/A"
    Physical Specs
    Height 324.0mm (12.8") 245.0mm (9.6")
    Width 221.0mm (8.7") 158.0mm (6.2")
    Depth 89.0mm (3.5") 52.0mm (2")
    Enclosure In-wall In-wall
    Moisture Resistancy Yes Yes
    Connections
    Biamp Inputs No No
    Other
    Parts Warranty Lifetime Lifetime
    Labor Warranty Lifetime Lifetime

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