In this review, we will be comparing Motion CI MW4-LCR and UIW RLS II, two Passive In-wall speakers from MartinLogan and Definitive Technology. Let's have a brief look at the main features
of MartinLogan Motion CI MW4-LCR and Definitive UIW RLS II first before getting into our more
detailed comparison.
MartinLogan Motion CI MW4-LCR Key Specs
- 2-way Design
- 1" Folded Motion Ribbon Tweeter
- 2 x 4" Fiberglass Woofer
- 78-25kHz Frequency Response
- 93 dB Sensitivity
- Impedance: 8ohms
- Power Range:50-100watts
- Dimensions (H x W x D): 134.0" x 11.8750" x 2.6875"( 134.0 x 302.0 x 69.0mm )
Definitive UIW RLS II Key Specs
- 2-way Design
- 1" Hard-Dome Tweeter
- 2 x 6.5" Polypropylene Woofer
- 22-30kHz Frequency Response
- 92 dB Sensitivity
- Impedance: 8ohms
- Power Range:10-350watts
- Dimensions (H x W x D): 724.0" x 7.0000" x 3.8750"( 724.0 x 178.0 x 99.0mm )
What size room are the MartinLogan Motion CI MW4-LCR and Definitive UIW RLS II 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* |
MartinLogan Motion CI MW4-LCR |
Definitive UIW RLS II |
| Near-field |
Average |
Are you nuts? |
| Small Room |
Good |
Bad |
| Mid-size Room |
Average |
Poor |
| Large Room |
Poor |
Good |
| Very Large Room |
Bad |
Good |
(* 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 MartinLogan Motion CI MW4-LCR and Definitive UIW RLS II 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 Motion CI MW4-LCR and UIW RLS II are 2-way speakers.
| Driver |
MartinLogan Motion CI MW4-LCR |
Definitive UIW RLS II |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 4-inch
|
2 x 6.5-inch
|
Motion CI MW4-LCR features a 1" Folded Motion Ribbon Tweeter and 2 x 4" Fiberglass Woofer . On the other hand, the UIW RLS II features a 1" Hard-Dome Tweeter and 2 x 6.5" Polypropylene Woofer .
Frequency Response
Motion CI MW4-LCR has a frequency range of 78-25kHz whereas UIW RLS II has a frequency range of 22-30kHz. With a minimum frequency of 22Hz, the UIW RLS II can go significantly deeper on the low side and provide stronger bass compared to the Motion CI MW4-LCR's min frequency of 78Hz.
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
MartinLogan Motion CI MW4-LCR
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
Motion CI MW4-LCR and UIW RLS II have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Motion CI MW4-LCR sensitivity is rated at 93 dB and the UIW RLS II's is at 92 dB. This 1 dB difference makes the MartinLogan Motion CI MW4-LCR a more sensitive speaker compared to Definitive UIW RLS II, 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.
Motion CI MW4-LCR can handle a max power of 350 watts RMS from the amp the whereas Motion CI MW4-LCR has a max power handling value of 100 watts RMS , 250 watts less than the UIW RLS II.
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
Motion CI MW4-LCR features Spring post type posts and UIW RLS II has a Spring post 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 MartinLogan Motion CI MW4-LCR's and Definitive UIW RLS II's external dimensions. MartinLogan Motion CI MW4-LCR has external dimensions of 134.0 x 302.0 x 69.0mm ( 5.2500-inch x 11.8750-inch x 2.6875-inch) whereas Definitive UIW RLS II has external dimensions of 724.0 x 178.0 x 99.0mm ( 28.5000-inch x 7.0000-inch x 3.8750-inch) .
MartinLogan Motion CI MW4-LCR is 590mm shorter and 30mm less deeper than Definitive UIW RLS II but it is also 124mm wider.
What's in the Box of MartinLogan Motion CI MW4-LCR?
Here are the items that are included inside the box of Motion CI MW4-LCR:
In-wall loudspeakerGrilleTorx-bitUser-feets ManualCutout Template
What's in the Box of Definitive UIW RLS II?
Here are the items that come with the UIW RLS II:
In-wall loudspeakerGrilleSelf-adhesive foam gasketPaint maskWall-Mount TemplateOwners ManualOnline Product Registration Card
Sensitivity 
Height 
Price per pair* 
Max Input Power 
Woofer Size 
High Frequency Response 
Passive Radiator 
Base Surface Area