In this review, we will be comparing two different types of speakers by MartinLogan. MartinLogan Motion 4i is a Bookshelf speaker whereas the Motion 30i is a Center Channel speaker.
Let's have a brief look at the main features
of MartinLogan Motion 4i and MartinLogan 30i first before getting into our more
detailed comparison.
| Key Specs | MartinLogan Motion 4i | MartinLogan 30i |
|---|
| Brand | MartinLogan
United States · founded 1982 | MartinLogan
United States · founded 1982 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1 x 1.4" Folded Motion Ribbon | 1.0 x 1.4" Folded Motion |
|---|
| Woofer | 4" | 5.25" Aluminum |
|---|
| Frequency response | 70-23k Hz | 65-25k Hz |
|---|
| Sensitivity | 90 dB | 91 dB |
|---|
| Impedance | 4 ohms | 4 ohms |
|---|
| Power range | — | 20-200 watts |
|---|
| Weight | 2.72kg / 6lbs | 8.18kg / 18lbs |
|---|
| Dimensions (H x W x D) | 12-11/16" x 5-11/16" x 5-11/16"
322.3 x 144.5 x 144.5mm | 6-15/16" x 16-5/8" x 11-1/16"
177.0 x 423.0 x 281.0mm |
|---|
Motion 4i and Motion 30i are members of MartinLogan's Motion series of speakers. Below you can find the loudspeakers from this series.
MartinLogan Motion Series
History
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Motion 4i and Motion 30i are 2-way speakers.
MartinLogan Motion 4iMartinLogan 30i
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 4i |
MartinLogan 30i |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1 x 1.4-inch
|
1.0 x 1.4-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 4-inch
|
1 x 5.25-inch
|
Motion 4i features a 1 x 1.4" Folded Motion Ribbon Tweeter and 1 x 4" Woofer. On the other hand, the Motion 30i features a 1.0 x 1.4" Folded Motion Tweeter and 1 x 5.25" Aluminum Woofer with a Crossover frequency at 400Hz and 2600Hz.
Frequency Response
Motion 4i has a frequency range of 70-23k Hz whereas Motion 30i has a frequency range of 65-25k Hz. With a minimum frequency of 65Hz, the Motion 30i can go significantly deeper on the low side and provide stronger bass compared to the Motion 4i's min frequency of 70Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf 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 4i and Motion 30i have the same Impedance of 4 ohms but where they differ is the sensitivity levels. Motion 4i sensitivity is rated at 90 dB and the Motion 30i's is at 91 dB. This 1 dB difference makes the MartinLogan 30i a more sensitive speaker compared to MartinLogan Motion 4i, hence will play louder with the same amount of watts.
One thing to keep in mind that the lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit comared to higher impedance speakers especially at high volume levels, so make sure the amp you pair with the Motion 4i and the Motion 4i can provide this impedance level.
Sensitivity
Bookshelf Speakers
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
Motion 4i features Custom 5-way tool-less binding posts type posts and Motion 30i has a Custom 5-way tool-less binding posts type posts. None of these speakers feature bi-amping/bi-wiring.
MartinLogan 30i'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 4i's and MartinLogan 30i's external dimensions. MartinLogan Motion 4i has external dimensions of 322.3 x 144.5 x 144.5mm () whereas MartinLogan 30i has external dimensions of 177.0 x 423.0 x 281.0mm (6-15/16 x 16-5/8 x 11-1/16inch).
MartinLogan Motion 4i is 278.5mm narrower and 136.5mm less deeper than MartinLogan 30i but it is also 145.3mm taller.
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 30i needs about 469% more floor or shelf area. MartinLogan 30i is 137mm deeper, so it stands that much further out from the wall. MartinLogan Motion 4i is 145mm 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 4i is approximately 208.8cm2 / 32.4inch2 and base area of the MartinLogan 30i is approximately 1188.6cm2 / 184.2inch2. The Motion 4i requires 82% less surface area than the Motion 30i which gives it a small advantage on placement in tight spaces.
What's in the Box of MartinLogan 30i?
Here are the items that come with the Motion 30i:
- Center-channel loudspeaker
- Grille
- 4 Rubber feet
- Users Manual
- Warranty/Registration Information