In this review, we will be comparing two different types of speakers by MartinLogan. MartinLogan Motion SLM X3 is a On-wall speaker whereas the Motion 15i is a Bookshelf speaker.
Let's have a brief look at the main features
of MartinLogan Motion SLM X3 and MartinLogan 15i first before getting into our more
detailed comparison.
| Key Specs | MartinLogan Motion SLM X3 | MartinLogan 15i |
|---|
| Brand | MartinLogan
United States · founded 1982 | MartinLogan
United States · founded 1982 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | AMT | 1.0 x 1.4" Folded Motion |
|---|
| Woofer | 6 x 4" Aluminium | 5.25" Aluminum |
|---|
| Frequency response | 120-25k Hz | 60-25k Hz |
|---|
| Sensitivity | 93 dB | 92 dB |
|---|
| Impedance | 4 ohms | 5 ohms |
|---|
| Power range | 20-140 watts | 20-200 watts |
|---|
| Weight | 5.90kg / 13lbs | 5.40kg / 11.9lbs |
|---|
| Dimensions (H x W x D) | 6-3/8" x 48-1/16" x 2"
162.0 x 1220.0 x 51.0mm | 11.4" x 6.8" x 9.4"
290.0 x 173.0 x 240.0mm |
|---|
Motion SLM X3 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 Motion SLM X3 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 Motion SLM X3 |
MartinLogan 15i |
| Near-field |
Good |
Poor |
| Small Room |
Good |
Average |
| Mid-size Room |
Average |
Good |
| Large Room |
Poor |
Average |
| Very Large Room |
No way |
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.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Motion SLM X3 and Motion 15i are 2-way speakers.
MartinLogan Motion SLM X3MartinLogan 15i
Woofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
MartinLogan Motion SLM X3 |
MartinLogan 15i |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
-inch
|
1.0 x 1.4-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
6 x 4-inch
|
1 x 5.25-inch
|
Motion SLM X3 features a " Folded Motion AMT Tweeter and 6 x 4" Aluminium Woofer with a Crossover frequency at 3,000 Hz. 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 SLM X3 has a frequency range of 120-25k 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 SLM X3's min frequency of 120Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the On-wall class in our database.
Low Frequency
On-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
Motion SLM X3 is a 4 ohms speaker compared to the Motion 15i which has a nominal impedance of 5 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 Motion SLM X3 can provide this impedance level.
These two speakers also have different sensitivity levels. Motion SLM X3 sensitivity is rated at 93 dB and the Motion 15i's is rated at 92 dB. This 1 dB difference makes the MartinLogan Motion SLM X3 a more sensitive speaker compared to MartinLogan 15i, hence will play louder with the same amount of watts.
Sensitivity
On-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.
Motion 15i can handle a max power of 200 watts RMS, whereas Motion SLM X3 has a max power handling value of 140 watts RMS, 60 watts less than the Motion 15i.
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.
MartinLogan Motion SLM X3
Input Type and Bi-Amping / Bi-Wiring
Motion SLM X3 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 15i's Custom 5-way tool-less binding posts terminals
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 MartinLogan Motion SLM X3's and MartinLogan 15i's external dimensions. MartinLogan Motion SLM X3 has external dimensions of 162.0 x 1220.0 x 51.0mm (6-3/8 x 48-1/16 x 2inch) whereas MartinLogan 15i has external dimensions of 290.0 x 173.0 x 240.0mm (11.4 x 6.8 x 9.4inch).
MartinLogan Motion SLM X3 is 128mm shorter and 189mm less deeper than MartinLogan 15i but it is also 1047mm wider.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
MartinLogan Motion SLM X3 needs about 50% more floor or shelf area. MartinLogan 15i is 189mm deeper, so it stands that much further out from the wall. MartinLogan 15i is 128mm taller.
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 Motion SLM X3 is approximately 622.2cm2 / 96.4inch2 and base area of the MartinLogan 15i is approximately 415.2cm2 / 64.4inch2. The Motion SLM X3 requires 50% 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 15i?
Here are the items that come with the Motion 15i:
- Bookshelf loudspeaker
- Grille
- 4 Rubber feet
- Users Manual
- Warranty/Registration Information