SpeakerDecision
  • SPEAKERS
    • By Type
      Passive Bookshelf Speakers Passive Floor-standing Speakers Passive Center Channel Speakers Passive In-wall Speakers All Passive Speakers Powered Subwoofers Powered Stereo Speakers
      By Feature
      HDMI Input Room Correction Subwoofer Output Front Firing Port Handheld Remote Roon Ready
      By Brand
      Acoustic Energy Aperion ATC Audio-Technica Audioengine Bluesound Bowers Wilkins Buchardt Cambridge Audio Canton DALI Definitive Technology Dynaudio ELAC Emotiva Fluance Focal Fyne Audio Genelec GoldenEar Harbeth Jamo JBL Kanto KEF KLH Klipsch Leak Mackie Magnepan MartinLogan McIntosh Mission MoFi Monitor Audio Nuvo Onkyo OSD Paradigm Perlisten Polk Audio PS Audio PSB Q Acoustics REL Revel Russound Sennheiser Sonos Sonus faber Sony Spendor SVS Tannoy Technics Triangle Velodyne Victrola Wharfedale Wilson Audio Yamaha
  • AMPLIFIERS
    • By Type
      All Amplifiers Integrated Amplifiers Stereo Receivers Streaming Amplifiers Power Amplifiers Compact Amplifiers
      By Power
      Up to 60 watts 61 to 90 watts 91 to 120 watts 121 to 180 watts Over 180 watts
      By Feature
      HDMI Input Room Correction Subwoofer Output Handheld Remote Roon Ready
      Home Theater
      All Home Theater Receivers Anthem ARCAM Denon Integra JBL Marantz McIntosh NAD Onkyo Sony Yamaha
      Headphone Amps
      All Headphone Amplifiers Cambridge Audio iFi Audio McIntosh Naim Pro-Ject Rotel Schiit Audio Sennheiser Yamaha
      Multi-Zone
      All Multi-Zone Amplifiers JBL McIntosh OSD Rotel Russound Sonos
      By Brand
      Accuphase Advance Paris Anthem Arcam Audio Research AudioControl Audioengine Audiolab Bluesound Bose Buchardt Cambridge Audio Cayin Denon Devialet ELAC Emotiva Eversolo FiiO Fosi Audio Hegel HiFi Rose Integra JBL Layer Audio Design LEAK Luxman Marantz Mark Levinson McIntosh Michi MISSION MOON Musical Fidelity NAD Naim Onkyo OSD Parasound Pass Labs Peachtree PrimaLuna Primare PS Audio Rega Rogue Audio Roksan Rotel Schiit Audio Sonos Sony SVS T+A TEAC Technics Vincent WiiM Yamaha
  • SMART FIND
  • TOOLS
  • BLOG
  1. Home
  2. MartinLogan Speakers
  3. MartinLogan Motion 4i vs MartinLogan 6i

MartinLogan Motion 4i vs MartinLogan 6i Comparison

x
Speaker to replace
Change

MartinLogan Motion 4i

Passive Bookshelf | 70-23k Hz

MartinLogan Motion 4i
Check price atAmazon›
Change
    
MartinLogan 6i

Passive Center Channel | 120-23k Hz

MartinLogan Motion 6i
Check price atAmazon›
MartinLogan Motion 4i MartinLogan Motion 4...
Check price atAmazon›
MartinLogan 6i MartinLogan 6i
Check price atAmazon›
MartinLogan Motion 4...
See at AMAZON
MartinLogan 6i
See at AMAZON

MartinLogan Motion 4i vs MartinLogan 6i Speaker Comparison

In this review, we will be comparing two different types of speakers by MartinLogan. MartinLogan Motion 4i is a Bookshelf speaker whereas the Motion 6i is a Center Channel speaker.

Let's have a brief look at the main features of MartinLogan Motion 4i and MartinLogan 6i first before getting into our more detailed comparison.

Key SpecsMartinLogan Motion 4iMartinLogan 6i
BrandMartinLogan
United States · founded 1982
MartinLogan
United States · founded 1982
Design2-way2-way
Tweeter1 x 1.4" Folded Motion Ribbon1.0 x 1.0" Folded Motion
Woofer4"2 x 3.5" poly cone woofers with rigid dust caps
Frequency response70-23k Hz120-23k Hz
Sensitivity90 dB89 dB
Impedance4 ohms6 ohms
Power range—20-130 watts
Weight2.72kg / 6lbs2.59kg / 5.7lbs
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
5-1/4" x 17-1/2" x 4"
134.0 x 445.0 x 102.0mm

Motion 4i and Motion 6i are members of MartinLogan's Motion series of speakers. Below you can find the loudspeakers from this series.

MartinLogan Motion Series History
Model Body Frequency SensitivityImpedance Woofer
MartinLogan 60XTi
  
Floor-standing 35-25k Hz 94 dB4Ω 2 x 8"
MartinLogan 15i
  
Bookshelf 60-25k Hz 92 dB5Ω 1 x 5.25"
MartinLogan 35XTi
  
Bookshelf 50-25k Hz 92 dB4Ω 1 x 6.5"
MartinLogan 40i
  
Floor-standing 40-25k Hz 92 dB4Ω 2 x 6.5"
MartinLogan 50XTi
  
Center Channel 50-25k Hz 94 dB4Ω 2 x 6.5"
MartinLogan 20i
  
Floor-standing 46-25k Hz 90 dB4Ω 2 x 5.5"
MartinLogan LX16
  
Bookshelf 60-25k Hz 92 dB5Ω 1 x 5.25"
MartinLogan 30i
  
Center Channel 65-25k Hz 91 dB4Ω 1 x 5.25"
MartinLogan 6i
Center Channel 120-23k Hz 89 dB6Ω 2 x 3.5"
MartinLogan 8i
  
Center Channel 70-23k Hz 89 dB4Ω 2 x 4"

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 6i are 2-way speakers.

Woofer - 4 inch
MartinLogan Motion 4i
Woofer - 3.5 inchWoofer - 3.5 inch
MartinLogan 6i

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 6i
Driver Setup 2-way 2-way
Tweeter 1 x 1.4-inch 1.0 x 1.0-inch
Midrange - -
Woofer 1 x 4-inch 2 x 3.5-inch

Motion 4i features a 1 x 1.4" Folded Motion Ribbon Tweeter and 1 x 4" Woofer. On the other hand, the 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.

Frequency Response

Motion 4i has a frequency range of 70-23k Hz whereas Motion 6i has a frequency range of 120-23k Hz. With a minimum frequency of 70Hz, the Motion 4i can go significantly deeper on the low side and provide stronger bass compared to the Motion 6i'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 Bookshelf class in our database.

Low Frequency

Bookshelf Speakers

Motion 4i
Motion 6i
Min
Average
Median

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 is a 4 ohms speaker compared to the Motion 6i which has a nominal impedance of 6 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 4i can provide this impedance level.

These two speakers also have different sensitivity levels. Motion 4i sensitivity is rated at 90 dB and the Motion 6i's is rated at 89 dB. This 1 dB difference makes the MartinLogan Motion 4i a more sensitive speaker compared to MartinLogan 6i, hence will play louder with the same amount of watts.

Sensitivity

Bookshelf Speakers

Motion 4i
Motion 6i
Min
Average
Median

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 4i
 
MartinLogan 6i
 

Input Type and Bi-Amping / Bi-Wiring

Motion 4i features Spring post type posts and Motion 6i has a Spring post type posts. None of these speakers feature bi-amping/bi-wiring.

MartinLogan 6i Terminals
MartinLogan 6i's Spring post 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 6i's external dimensions. MartinLogan Motion 4i has external dimensions of 322.3 x 144.5 x 144.5mm () whereas MartinLogan 6i has external dimensions of 134.0 x 445.0 x 102.0mm (5-1/4 x 17-1/2 x 4inch).

MartinLogan 6i is 188.3mm shorter and 42.5mm less deeper than MartinLogan Motion 4i but it is also 300.5mm wider.

Size, drawn to scale

FRONTMartinLogan Motion 4i front: 145 x 322 mm (5.7 x 12.7 in)MartinLogan 6i front: 445 x 134 mm (17.5 x 5.3 in)MartinLogan Motion 4i145 × 322 mmMartinLogan 6i445 × 134 mmTOP / FOOTPRINTMartinLogan Motion 4i footprint: 145 x 145 mm (5.7 x 5.7 in)MartinLogan 6i footprint: 445 x 102 mm (17.5 x 4 in)MartinLogan Motion 4i145 × 145 mmMartinLogan 6i445 × 102 mm
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 6i needs about 117% more floor or shelf area. MartinLogan Motion 4i is 43mm deeper, so it stands that much further out from the wall. MartinLogan Motion 4i is 188mm 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 6i is approximately 453.9cm2 / 70.4inch2. The Motion 4i requires 54% less surface area than the Motion 6i which gives it a small advantage on placement in tight spaces.

What's in the Box of MartinLogan 6i?

Here are the items that come with the Motion 6i:
  • LCR loudspeaker
  • Grille
  • 2 Wall-bracket
  • 2 Shoulder bolts
  • 4 Rubber bumpers
  • Cleaning cloth
  • User-feets Manual (En/Fr)
  • Installation template
  • Product Registration Card


Reasons to choose MartinLogan Motion 4i over MartinLogan Motion 6i

Sensitivity 90 dB vs 89 dB Play louder with same amount of amplification power
Woofer Size 4 inches vs 3.5 inches Larger woofer
Low Frequency Response 70 Hz vs 120 Hz Generates deeper bass
Base Surface Area 208cm2 vs 453cm2 Takes less floor space

Reasons to choose MartinLogan Motion 6i over MartinLogan Motion 4i

Nominal Impedance 6 ohms vs 4 ohms Less selective with amplifiers
Number of Woofers 2 vs 1 More woofers
Height 134mm vs 322mm Easier to fit in smaller spaces

MartinLogan Motion 4i vs MartinLogan 6i Specs Table

Detailed comparison of specifications
General MartinLogan Motion 4i MartinLogan Motion 6i
Brand MartinLogan MartinLogan
Speaker Type Bookshelf speakers Center channel speaker
Sensitivity 90 dB 89 dB
Impedance 4 ohms 6 ohms
Frequency Response 70-23k Hz 120-23k Hz
Drivers
Woofer Quantity 1 2
Woofer Size 4" 3.5"
Woofer Composition poly cone woofers with rigid dust caps
Tweeter Size 1 x 1.4" 1.0 x 1.0"
Tweeter Type Folded Motion Ribbon Folded Motion
Aimable Tweeter No No
Midrange Driver No No
Suggested Break-in Period n/a Allow 72 hours of break-in at 90 dB
Physical Specs
Height 322.3mm (12.7") 134.0mm (5.3")
Width 144.5mm (5.7") 445.0mm (17.5")
Depth 144.5mm (5.7") 102.0mm (4")
Weight 2.72kg (6lbs) 2.59kg (5.7lbs)
Enclosure Passive Radiator
Finish Piano Lacquer n/a
Available Colors Gloss Black Gloss Black, Matt White, Red Walnut
Mounting Bracket No
Grille n/a Yes
Moisture Resistancy No No
Connections
Other
Parts Warranty 5 Yrs w/ Registration 5 Yrs w/ Registration
Labor Warranty 5 Yrs w/ Registration 5 Yrs w/ Registration

Verdict

Siblings in MartinLogan's Motion series, so they share a family sound. It comes down to size, output and price.

AreaBetterWhy
BassAMartinLogan Motion 4i digs deeper - 70Hz against 120Hz.
Amplifier needsevenly matchedSimilar sensitivity (90dB vs 89dB) - both want much the same power.
Amplifier matchBMartinLogan 6i is the easier load at 6 ohms; the other is 4 ohms and wants an amplifier rated for it.
SizedependsSimilar cabinet size - neither is easier to fit.
TypedependsA Passive Bookshelf against a Passive Center Channel - a different job rather than a better one.
CabinetdependsPorted vs Passive Radiator.

A MartinLogan Motion 4i  B MartinLogan 6i
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.

Which should you choose?

Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 120Hz anyway, so judge these on the other rows instead. If your amplifier is modest, vintage or valve-based, MartinLogan 6i is the safer partner - the other will want more current or more watts to sound its best.

And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.


Most Popular Speakers
Klipsch Reference R-51M
Klipsch R-51M
2-way | 93 dB | 8 ohms
ELAC Debut 2.0 B6.2
ELAC Debut 2.0 B6.2
2-way | 87 dB | 6 ohms
Wharfedale Elysian 2
Wharfedale Elysian 2
3-way | 89 dB | 4 ohms
KEF Q150
KEF Q150
2-way | 86 dB | 8 ohms
Bowers & Wilkins 606 S2 Anniversary Edition
B&W 606 S2
2-way | 88 dB | 8 ohms
Klipsch Reference Premiere RP-500M
Klipsch RP-500M
2-way | 93 dB | 8 ohms
Wharfedale EVO5.1
Wharfedale EVO5.1
2-way | 87 dB | 4 ohms
Wharfedale EVO4.1
Wharfedale EVO4.1
2-way | 87 dB | 8 ohms
This site contains affiliate links. We may be compensated if you make a purchase after clicking through one of them. As an Amazon Associate we earn from qualifying purchases.
Copyright © 2026 by SpeakerDecision
About Privacy Contact US Camera Decision

Report a Correction