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ELAC IW-DC51-W vs Polk Audio RC85i Comparison

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ELAC IW-DC51-W

Passive In-wall | 45-20kHz

ELAC IW-DC51-W
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Polk Audio RC85i

Passive In-wall | 50-20kHz

Polk Audio RC85i
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ELAC IW-DC51-W ELAC IW-DC51-W
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Polk Audio RC85i Polk Audio RC85i
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ELAC IW-DC51-W
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Polk Audio RC85i
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ELAC IW-DC51-W vs Polk Audio RC85i Speaker Comparison

In this review, we will be comparing IW-DC51-W and RC85i, two Passive In-wall speakers from ELAC and Polk Audio.

Let's have a brief look at the main features of ELAC IW-DC51-W and Polk Audio RC85i first before getting into our more detailed comparison.

ELAC IW-DC51-W Key Specs

  • 2-way Design
  • 1" Soft-Dome Tweeter
  • 5.25" Woven Aramid-Fiber Woofer
  • 45-20kHz Frequency Response
  • 87 dB Sensitivity
  • Impedance: 6ohms
  • Power Range:30-120watts
  • Dimensions (H x W x D): 159.0" x 16.5000" x 3.3750"( 159.0 x 420.0 x 86.0mm )

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 ELAC IW-DC51-W 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* ELAC IW-DC51-W Polk Audio RC85i
Near-field Poor Average
Small Room Average Good
Mid-size Room Good Average
Large Room Average Poor
Very Large Room Poor 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 ELAC IW-DC51-W 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.


**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 IW-DC51-W and RC85i are 2-way speakers.

Driver ELAC IW-DC51-W Polk Audio RC85i
Driver Setup 2-way 2-way
Tweeter 1-inch 1-inch
Midrange - -
Woofer 1 x 5.25-inch 1 x 8-inch

IW-DC51-W features a 1" Soft-Dome Tweeter and 1 x 5.25" Woven Aramid-Fiber Woofer . On the other hand, the RC85i features a 1" Hard-Dome Tweeter and 1 x 8" Polypropylene Woofer .

Frequency Response

IW-DC51-W has a frequency range of 45-20kHz whereas RC85i has a frequency range of 50-20kHz. With a minimum frequency of 45Hz, the IW-DC51-W 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

IW-DC51-W
RC85i
Min
Average
Max
High Frequency

In-wall Speakers

ELAC IW-DC51-W
Polk Audio RC85i
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

IW-DC51-W is a 6 ohms speaker compared to the RC85i which has a nominal impedance of 8 ohms.

These two speakers also have different sensitivity levels. IW-DC51-W sensitivity is rated at 87 dB and the RC85i's is rated at 90 dB. This 3 dB difference makes the Polk Audio RC85i a more sensitive speaker compared to ELAC IW-DC51-W, hence will play louder with the same amount of watts.

Sensitivity

In-wall Speakers

IW-DC51-W
RC85i
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.

IW-DC51-W can handle a max power of 120 watts RMS from the amp the whereas RC85i has a max power handling value of 100 watts RMS, 20 watts less than the IW-DC51-W.

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

IW-DC51-W 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 ELAC IW-DC51-W's and Polk Audio RC85i's external dimensions. ELAC IW-DC51-W has external dimensions of 159.0 x 420.0 x 86.0mm ( 6.2500-inch x 16.5000-inch x 3.3750-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) .

ELAC IW-DC51-W is 165mm shorter and 3mm less deeper than Polk Audio RC85i but it is also 199mm wider.

What's in the Box of ELAC IW-DC51-W?

Here are the items that are included inside the box of IW-DC51-W:
  • In-wall center-channel speaker
  • Grille
  • What's in the Box of Polk Audio RC85i?

    Here are the items that come with the RC85i:
  • 2 White in-wall speakers
  • 2 White grilles
  • 1 Cardboard Mounting Template
  • Owners Manual
  • Online registration sheet
  • Product Registration Card

  • Reasons to choose ELAC IW-DC51-W over Polk Audio RC85i
    Max Input Power 120 watts vs 100 watts Handle more power from your amplifier
    Low Frequency Response 45 Hz vs 50 Hz Generates deeper bass
    Height 159mm vs 324mm Easier to fit in smaller spaces

    Reasons to choose Polk Audio RC85i over ELAC IW-DC51-W

    Sensitivity 90 dB vs 87 dB Play louder with same amount of amplification power
    Nominal Impedance 8 ohms vs 6 ohms Less selective with amplifiers
    Woofer Size 8 inches vs 5.25 inches Larger woofer
    Base Surface Area 196cm2 vs 361cm2 Takes less floor space
    Price per pair* 279USD vs 660USD costs less (*prices may change depending on the seller, location and time)
    ELAC IW-DC51-W vs Polk Audio RC85i Specs Table
    Detailed comparison of specifications
    General ELAC IW-DC51-W Polk Audio RC85i
    Brand ELAC Polk Audio
    Speaker Type Passive In-wall Speaker Passive In-wall Speaker
    Power Range 30-120 watts 20-100 watts
    Sensitivity 87 dB 90 dB
    Impedance 6 ohms 8 ohms
    Frequency Response 45-20kHz 50-20kHz
    Drivers
    Woofer Quantity 1 1
    Woofer Size 5.25" 8"
    Woofer Composition Woven Aramid-Fiber Polypropylene
    Woofer Surround Material Rubber Rubber
    Tweeter Size 1" 1"
    Tweeter Type Soft-Dome Hard-Dome
    Aimable Tweeter No Yes
    Midrange Driver N/A" N/A"
    Physical Specs
    Height 159.0mm (6.3") 324.0mm (12.8")
    Width 420.0mm (16.5") 221.0mm (8.7")
    Depth 86.0mm (3.4") 89.0mm (3.5")
    Enclosure In-wall In-wall
    Moisture Resistancy No Yes
    Connections
    Biamp Inputs No No
    Other
    Parts Warranty 3 Years Lifetime
    Labor Warranty 3 Years Lifetime

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