In this review, we will be comparing C-8IW and RC85i, two Passive In-wall speakers from JBL and Polk Audio. Let's have a brief look at the main features
of JBL C Series C-8IW and Polk Audio RC85i first before getting into our more
detailed comparison.
JBL C Series C-8IW Key Specs
- 2-way Design
- 0.5" Soft-Dome Tweeter
- 8" Poly Woofer
- 45-20kHz Frequency Response
- 89 dB Sensitivity
- Impedance: 8ohms
- Power Range:up to 45watts
- Dimensions (H x W x D): 328.0" x 8.7500" x 3.2500"( 328.0 x 223.0 x 83.0mm )
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 )
What size room are the JBL C Series C-8IW and Polk Audio RC85i 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* |
JBL C Series C-8IW |
Polk Audio RC85i |
| Near-field |
Good |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
No way |
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 JBL C Series C-8IW and Polk Audio RC85i 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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Drivers
Both C-8IW and RC85i are 2-way speakers.
| Driver |
JBL C Series C-8IW |
Polk Audio RC85i |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
0.5-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 8-inch
|
1 x 8-inch
|
C-8IW features a 0.5" Soft-Dome Tweeter and 1 x 8" Poly Woofer . On the other hand, the RC85i features a 1" Hard-Dome Tweeter and 1 x 8" Polypropylene Woofer .
Frequency Response
C-8IW has a frequency range of 45-20kHz whereas RC85i has a frequency range of 50-20kHz. With a minimum frequency of 45Hz, the C-8IW can go significantly deeper on the low side and provide stronger bass compared to the RC85i's min frequency of 50Hz.
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
High Frequency
In-wall 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
C-8IW and RC85i have the same Impedance of 8 ohms but where they differ is the sensitivity levels. C-8IW sensitivity is rated at 89 dB and the RC85i's is at 90 dB. This 1 dB difference makes the Polk Audio RC85i a more sensitive speaker compared to JBL C Series C-8IW, 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. 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.
C-8IW can handle a max power of 100 watts RMS from the amp the whereas C-8IW has a max power handling value of 45 watts RMS , 55 watts less than the RC85i.
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
C-8IW features Spring clip type posts and RC85i 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 JBL C Series C-8IW's and Polk Audio RC85i's external dimensions. JBL C Series C-8IW has external dimensions of 328.0 x 223.0 x 83.0mm ( 12.8750-inch x 8.7500-inch x 3.2500-inch) whereas 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) .
Polk Audio RC85i is 2mm narrower and 4mm shorter than JBL C Series C-8IW but it is also 6mm deeper.
What's in the Box of JBL C Series C-8IW?
Here are the items that are included inside the box of C-8IW:
In-wall loudspeakerGrillePaint shieldCut-Out TemplateOwners ManualWarranty CardImportant Safety Instructions
What's in the Box of Polk Audio RC85i?
Here are the items that come with the RC85i:
2 White in-wall speakers2 White grilles1 Cardboard Mounting TemplateOwners ManualOnline registration sheetProduct Registration Card
Low Frequency Response 
Base Surface Area 
Price per pair* 
Max Input Power 
Sensitivity 
Height