In this review, we will be comparing two different type of speakers by MartinLogan. MartinLogan Motion 6i is a Center Channel speaker whereas the Motion 15i is a Bookshelf speaker.
Let's have a brief look at the main features
of MartinLogan 6i and MartinLogan 15i first before getting into our more
detailed comparison.
MartinLogan 6i Key Specs
- 2-way Design
- 1.0 x 1.0" Folded Motion Tweeter
- 2 x 3.5" poly cone woofers with rigid dust caps Woofer
- 120-23k Hz Frequency Response
- 89 dB Sensitivity
- Impedance: 6ohms
- Power Range:20-130watts
- Weight:2.59kg
- Dimensions (H x W x D): 134.0" x 17-1/2" x 4"( 134.0 x 445.0 x 102.0mm )
MartinLogan 15i Key Specs
- 2-way Design
- 1.0 x 1.4" Folded Motion Tweeter
- 5.25" Aluminum Woofer
- 60-25k Hz Frequency Response
- 92 dB Sensitivity
- Impedance: 5ohms
- Power Range:20-200watts
- Weight:5.40kg
- Dimensions (H x W x D): 290.0" x 6.8" x 9.4"( 290.0 x 173.0 x 240.0mm )
Motion 6i and Motion 15i are members of MartinLogan's Motion series of speakers. Below you can find the loudspeakers from this series.
MartinLogan Motion Series History
What size room are the MartinLogan 6i and MartinLogan 15i 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 6i |
MartinLogan 15i |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
Poor |
(* 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 6i and MartinLogan 15i 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 Motion 6i and Motion 15i are 2-way speakers.
| Driver |
MartinLogan 6i |
MartinLogan 15i |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.0 x 1.0-inch
|
1.0 x 1.4-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 3.5-inch
|
1 x 5.25-inch
|
Motion 6i features a 1.0 x 1.0" Folded Motion Tweeter and 2 x 3.5" poly cone woofers with rigid dust caps Woofer . On the other hand, the Motion 15i features a 1.0 x 1.4" Folded Motion Tweeter and 1 x 5.25" Aluminum Woofer with a Crossover frequency at 2700Hz.
Frequency Response
Motion 6i has a frequency range of 120-23k Hz whereas Motion 15i has a frequency range of 60-25k Hz. With a minimum frequency of 60Hz, the Motion 15i can go significantly deeper on the low side and provide stronger bass compared to the Motion 6i's min frequency of 120Hz.
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 Center Channel class in our database.
Low Frequency
Center Channel Speakers
High Frequency
Center Channel 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
Motion 6i is a 6 ohms speaker compared to the Motion 15i which has a nominal impedance of 5 ohms.
These two speakers also have different sensitivity levels. Motion 6i sensitivity is rated at 89 dB and the Motion 15i's is rated at 92 dB. This 3 dB difference makes the MartinLogan 15i a more sensitive speaker compared to MartinLogan 6i, hence will play louder with the same amount of watts.
Sensitivity
Center Channel 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 6i can handle a max power of 200 watts RMS from the amp the whereas Motion 6i has a max power handling value of 130 watts RMS , 70 watts less than the Motion 15i.
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 6i features Custom 5-way tool-less binding posts type posts and Motion 15i has a Custom 5-way tool-less binding posts type posts. None of these speakers feature bi-amping/bi-wiring.
MartinLogan 6i's Spring post terminals
MartinLogan 15i's Custom 5-way tool-less binding posts terminals
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 6i's and MartinLogan 15i's external dimensions. MartinLogan 6i has external dimensions of 134.0 x 445.0 x 102.0mm ( 5-1/4 x 17-1/2 x 4inch) whereas MartinLogan 15i has external dimensions of 290.0 x 173.0 x 240.0mm ( 11.4 x 6.8 x 9.4inch) .
MartinLogan 6i is 156mm shorter and 138mm less deeper than MartinLogan 15i but it is also 272mm wider.
Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base surface area of the MartinLogan 6i is approximately 453.9cm2 / 70.4inch2 and base area of the MartinLogan 15i is approximately 415.2cm2 / 64.4inch2. The Motion 6i requires 9% more surface area than the Motion 15i which gives it a small disadvantage on placement in tight spaces.
What's in the Box of MartinLogan 6i?
Here are the items that are included inside the box of Motion 6i:
LCR loudspeakerGrille2 Wall-bracket2 Shoulder bolts4 Rubber bumpersCleaning clothUser-feets Manual (En/Fr)Installation templateProduct Registration Card
What's in the Box of MartinLogan 15i?
Here are the items that come with the Motion 15i:
Bookshelf loudspeaker Grille 4 Rubber feet Users Manual Warranty/Registration Information
Nominal Impedance 
Number of Woofers 
Height 
Price per pair* 
Max Input Power 
Sensitivity 
High Frequency Response 
Base Surface Area