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.
| Key Specs | Polk Audio RC85i | Polk Audio RC55i |
|---|
| Brand | Polk Audio
United States · founded 1972 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Hard-Dome | 0.75" Hard-Dome |
|---|
| Woofer | 8" Polypropylene | 5.25" Polypropylene |
|---|
| Frequency response | 50-20kHz | 70-20kHz |
|---|
| Sensitivity | 90 dB | 89 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 20-100 watts | 20-100 watts |
|---|
| Dimensions (H x W x D) | 12.7500" x 8.6875" x 3.5000"
324.0 x 221.0 x 89.0mm | 9.6250" x 6.1875" x 2.0120"
245.0 x 158.0 x 52.0mm |
|---|
RC85i and RC55i are members of Polk Audio's RC series of speakers. Below you can find the loudspeakers from this series.
Polk Audio RC Series
History
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.)
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 RC85i and RC55i are 2-way speakers.
Polk Audio RC85iPolk Audio RC55i
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 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.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the In-wall class in our database.
Low Frequency
In-wall 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
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
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.
RC85i and RC55i have the same power range of 20-100 watts.
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
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
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 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