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.
| Key Specs | ELAC IW-DC51-W | Polk Audio RC85i |
|---|
| Brand | ELAC
Germany · founded 1926 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Hard-Dome |
|---|
| Woofer | 5.25" Woven Aramid-Fiber | 8" Polypropylene |
|---|
| Frequency response | 45-20kHz | 50-20kHz |
|---|
| Sensitivity | 87 dB | 90 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | 30-120 watts | 20-100 watts |
|---|
| Weight | 4.85kg / 10.7lbs | — |
|---|
| Dimensions (H x W x D) | 6.2500" x 16.5000" x 3.3750"
159.0 x 420.0 x 86.0mm | 12.7500" 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.)
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 IW-DC51-W and RC85i are 2-way speakers.
ELAC IW-DC51-WPolk Audio RC85i
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| 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.
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
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
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.
IW-DC51-W can handle a max power of 120 watts RMS, whereas RC85i has a max power handling value of 100 watts RMS, 20 watts less than the IW-DC51-W.
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
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
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 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