In this review, we will be comparing IW Sub Reference and Motion CI MW4-LCR, two Passive In-wall speakers from Definitive Technology and MartinLogan. Let's have a brief look at the main features
of Definitive IW Sub Reference and MartinLogan Motion CI MW4-LCR first before getting into our more
detailed comparison.
Definitive IW Sub Reference Key Specs
- 1-way Design
- " Tweeter
- 13" Not given Woofer
- 14-200Hz Frequency Response
- --- Sensitivity
- Impedance: 4ohms
- Power Range:up to 275watts
- Dimensions (H x W x D): 639.0" x 14.3750" x 4.0000"( 639.0 x 366.0 x 102.0mm )
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 )
What size room are the Definitive IW Sub Reference and MartinLogan Motion CI MW4-LCR 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* |
Definitive IW Sub Reference |
MartinLogan Motion CI MW4-LCR |
| Near-field |
Poor |
Average |
| Small Room |
Poor |
Good |
| Mid-size Room |
Good |
Average |
| Large Room |
Good |
Poor |
| Very Large Room |
Average |
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 Definitive IW Sub Reference and MartinLogan Motion CI MW4-LCR 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
One of the fundamental differences between these two speakers is that IW Sub Reference is a 1-way design whereas the Motion CI MW4-LCR is a 2-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
| Driver |
Definitive IW Sub Reference |
MartinLogan Motion CI MW4-LCR |
|
Driver Setup
|
1-way
|
2-way
|
|
Tweeter
|
-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 13-inch
|
2 x 4-inch
|
IW Sub Reference features a " Tweeter and 1 x 13" Not given Woofer . On the other hand, the Motion CI MW4-LCR features a 1" Folded Motion Ribbon Tweeter and 2 x 4" Fiberglass Woofer .
Frequency Response
IW Sub Reference has a frequency range of 14-200Hz whereas Motion CI MW4-LCR has a frequency range of 78-25kHz. With a minimum frequency of 14Hz, the IW Sub Reference 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
Definitive IW Sub Reference
MartinLogan Motion CI MW4-LCR
Impedance and Sensitivity
IW Sub Reference is a 4 ohms speaker compared to the Motion CI MW4-LCR which has a nominal impedance of 8 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the IW Sub Reference can provide this impedance level.
These two speakers also have different sensitivity levels. IW Sub Reference sensitivity is rated at --- and the Motion CI MW4-LCR's is rated at 93 dB. This 93 dB difference makes the MartinLogan Motion CI MW4-LCR a more sensitive speaker compared to Definitive IW Sub Reference, 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.
IW Sub Reference can handle a max power of 275 watts RMS from the amp the whereas Motion CI MW4-LCR has a max power handling value of 100 watts RMS, 175 watts less than the IW Sub Reference.
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 Sub Reference features Spring post type posts and Motion CI MW4-LCR 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 Definitive IW Sub Reference's and MartinLogan Motion CI MW4-LCR's external dimensions. Definitive IW Sub Reference has external dimensions of 639.0 x 366.0 x 102.0mm ( 25.1250-inch x 14.3750-inch x 4.0000-inch) whereas 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) .
Definitive IW Sub Reference is clearly the larger of the two speakers. Its body is 64mm wider, 505mm taller and 33mm deeper than MartinLogan Motion CI MW4-LCR.
What's in the Box of Definitive IW Sub Reference?
Here are the items that are included inside the box of IW Sub Reference:
In-wall subwooferGrille (attached)4 Long self-adhesive foam gaskets3 Short self-adhesive foam gaskets8 ScrewsWall-templatePaint maskOwners ManualOnline Product Registration card
What's in the Box of MartinLogan Motion CI MW4-LCR?
Here are the items that come with the Motion CI MW4-LCR:
In-wall loudspeakerGrilleTorx-bitUser-feets ManualCutout Template
Max Input Power 
Woofer Size 
High Frequency Response 
Passive Radiator 
Driver Setup 
Nominal Impedance 
Height 
Base Surface Area 
Price per pair*