In this review, we will be comparing Motion 8i and Motion 6i, two Passive Center Channel speakers by MartinLogan.
Let's have a brief look at the main features
of MartinLogan 8i and MartinLogan 6i first before getting into our more
detailed comparison.
| Key Specs | MartinLogan 8i | MartinLogan 6i |
|---|
| Brand | MartinLogan
United States · founded 1982 | MartinLogan
United States · founded 1982 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1.0 x 1.4" Folded Motion | 1.0 x 1.0" Folded Motion |
|---|
| Woofer | 2 x 4" poly cone woofers with rigid dust caps | 2 x 3.5" poly cone woofers with rigid dust caps |
|---|
| Frequency response | 70-23k Hz | 120-23k Hz |
|---|
| Sensitivity | 89 dB | 89 dB |
|---|
| Impedance | 4 ohms | 6 ohms |
|---|
| Power range | 20-180 watts | 20-130 watts |
|---|
| Weight | 3.86kg / 8.5lbs | 2.59kg / 5.7lbs |
|---|
| Dimensions (H x W x D) | 5-9/16" x 22-1/8" x 5-1/4"
142.0 x 562.0 x 134.0mm | 5-1/4" x 17-1/2" x 4"
134.0 x 445.0 x 102.0mm |
|---|
Motion 8i 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
What size room are the MartinLogan 8i and MartinLogan 6i 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 8i |
MartinLogan 6i |
| 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.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Motion 8i and Motion 6i are 2-way speakers.
MartinLogan 8iMartinLogan 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 8i |
MartinLogan 6i |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.0 x 1.4-inch
|
1.0 x 1.0-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 4-inch
|
2 x 3.5-inch
|
Motion 8i features a 1.0 x 1.4" Folded Motion Tweeter and 2 x 4" poly cone woofers with rigid dust caps 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 8i 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 8i 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 Center Channel class in our database.
Low Frequency
Center Channel 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 8i 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 8i can provide this impedance level.
On the other hand, they have the same sensitivity of 89 dBdB.
Sensitivity
Center Channel 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 8i can handle a max power of 180 watts RMS, whereas Motion 6i has a max power handling value of 130 watts RMS, 50 watts less than the Motion 8i.
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.
Input Type and Bi-Amping / Bi-Wiring
Motion 8i features Spring post type posts and Motion 6i has a Spring post type posts. None of these speakers feature bi-amping/bi-wiring.
MartinLogan 8i's Spring post 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 8i's and MartinLogan 6i's external dimensions. MartinLogan 8i has external dimensions of 142.0 x 562.0 x 134.0mm (5-9/16 x 22-1/8 x 5-1/4inch) 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 8i is clearly the larger of the two speakers. Its body is 117mm wider, 8mm taller and 32mm deeper than MartinLogan 6i.
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 8i is approximately 753.1cm2 / 116.7inch2 and base area of the MartinLogan 6i is approximately 453.9cm2 / 70.4inch2. The Motion 8i requires 66% more surface area than the Motion 6i which gives it a small disadvantage on placement in tight spaces.
Weight Comparison The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The MartinLogan 8i weighs 3.86kg / 8.5lbs and the MartinLogan 6i weighs 2.59kg / 5.7lbs. This makes the Motion 8i 49% heavier than the Motion 6i.
Here is a comparison of how Motion 8i and Motion 6i's weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
What's in the Box of MartinLogan 8i?
Here are the items that are included inside the box of Motion 8i:
- LCR loudspeaker
- Grille
- 2 Wall-bracket
- 2 Shoulder bolts
- 4 Rubber bumpers
- Cleaning cloth
- User-feets Manual (En/Fr)
- Installation template
- Product Registration Card
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
 Max Input Power |
180 watts
vs
130 watts
|
Handle more power from your amplifier |
 Woofer Size |
4 inches
vs
3.5 inches
|
Larger woofer |
|
Low Frequency Response |
70 Hz
vs
120 Hz
|
Generates deeper bass |
 Nominal Impedance |
6 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Height |
134mm
vs
142mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
453cm2
vs
753cm2
|
Takes less floor space |
 Price per pair* |
300USD
vs
450USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
MartinLogan Motion 8i |
MartinLogan Motion 6i |
| Brand |
MartinLogan |
MartinLogan |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
20-180 watts |
20-130 watts |
| Sensitivity |
89 dB |
89 dB |
| Impedance |
4 ohms |
6 ohms |
| Frequency Response |
70-23k Hz |
120-23k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
4" |
3.5" |
| Woofer Composition |
poly cone woofers with rigid dust caps |
poly cone woofers with rigid dust caps |
| Tweeter Size |
1.0 x 1.4" |
1.0 x 1.0" |
| Tweeter Type |
Folded Motion |
Folded Motion |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Suggested Break-in Period |
Allow 72 hours of break-in at 90 dB |
Allow 72 hours of break-in at 90 dB |
Physical Specs |
|
|
| Height |
142.0mm (5.6") |
134.0mm (5.3") |
| Width |
562.0mm (22.1") |
445.0mm (17.5") |
| Depth |
134.0mm (5.3") |
102.0mm (4") |
| Weight |
3.86kg (8.5lbs) |
2.59kg (5.7lbs) |
| Enclosure |
Passive Radiator |
Passive Radiator |
| Available Colors |
Gloss Black, Matt White, Red Walnut |
Gloss Black, Matt White, Red Walnut |
| Grille |
Yes |
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 |
Siblings in MartinLogan's Motion series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | A | MartinLogan 8i digs deeper - 70Hz against 120Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (89dB vs 89dB) - both want much the same power. |
| Amplifier match | B | MartinLogan 6i is the easier load at 6 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | A | MartinLogan 8i takes more power (180W vs 130W) - more in hand in a big room. |
| Size | depends | MartinLogan 6i is easier to place; MartinLogan 8i is bigger, which usually goes with fuller bass. Your room decides. |
| Price | B | MartinLogan 6i is cheaper - $300 against $450, about 33% less. |
A MartinLogan 8i 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?
MartinLogan 8i is ahead, but only on 1 of the measured areas, and it costs about 50% more. That is a lot of money for a narrow margin on paper - MartinLogan 6i looks like the sensible buy unless something else about the MartinLogan 8i appeals to you. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 120Hz anyway, which makes the cheaper MartinLogan 6i much easier to justify. In a large or open-plan room, MartinLogan 8i has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, MartinLogan 6i is the easier speaker to get right.
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.