In this review, we will be comparing Motion 8i and Motion 30i, two Passive Center Channel speakers by MartinLogan.
Let's have a brief look at the main features
of MartinLogan 8i and MartinLogan 30i first before getting into our more
detailed comparison.
| Key Specs | MartinLogan 8i | MartinLogan 30i |
|---|
| 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 1.4" Folded Motion |
|---|
| Woofer | 2 x 4" poly cone woofers with rigid dust caps | 5.25" Aluminum |
|---|
| Frequency response | 70-23k Hz | 65-25k Hz |
|---|
| Sensitivity | 89 dB | 91 dB |
|---|
| Impedance | 4 ohms | 4 ohms |
|---|
| Power range | 20-180 watts | 20-200 watts |
|---|
| Weight | 3.86kg / 8.5lbs | 8.18kg / 18lbs |
|---|
| 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 | 6-15/16" x 16-5/8" x 11-1/16"
177.0 x 423.0 x 281.0mm |
|---|
Motion 8i 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
What size room are the MartinLogan 8i and MartinLogan 30i 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 30i |
| 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 30i are 2-way speakers.
MartinLogan 8iMartinLogan 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 8i |
MartinLogan 30i |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.0 x 1.4-inch
|
1.0 x 1.4-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 4-inch
|
1 x 5.25-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 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 8i 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 8i'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 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 and Motion 30i have the same Impedance of 4 ohms but where they differ is the sensitivity levels. Motion 8i sensitivity is rated at 89 dB and the Motion 30i's is at 91 dB. This 2 dB difference makes the MartinLogan 30i a more sensitive speaker compared to MartinLogan 8i, 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 8i and the Motion 8i can provide this impedance level.
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 30i can handle a max power of 200 watts RMS, whereas Motion 8i has a max power handling value of 180 watts RMS, 20 watts less than the Motion 30i.
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 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 8i's Spring post terminals
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 8i's and MartinLogan 30i'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 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 8i is 35mm shorter and 147mm less deeper than MartinLogan 30i but it is also 139mm 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 8i is approximately 753.1cm2 / 116.7inch2 and base area of the MartinLogan 30i is approximately 1188.6cm2 / 184.2inch2. The Motion 8i requires 37% less surface area than the Motion 30i which gives it a small advantage 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 30i weighs 8.18kg / 18lbs. This makes the Motion 30i 112% heavier than the Motion 8i.
Here is a comparison of how Motion 8i and Motion 30i'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 30i?
Here are the items that come with the Motion 30i:
- Center-channel loudspeaker
- Grille
- 4 Rubber feet
- Users Manual
- Warranty/Registration Information
 Number of Woofers |
2
vs
1
|
More woofers |
 Height |
142mm
vs
177mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
753cm2
vs
1188cm2
|
Takes less floor space |
 Price per pair* |
450USD
vs
900USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
200 watts
vs
180 watts
|
Handle more power from your amplifier |
 Sensitivity |
91 dB
vs
89 dB
|
Play louder with same amount of amplification power |
|
Woofer Size |
5.25 inches
vs
4 inches
|
Larger woofer |
|
Low Frequency Response |
65 Hz
vs
70 Hz
|
Generates deeper bass |
 High Frequency Response |
25k Hz
vs
23k Hz
|
Generates higher frequency |
| General |
MartinLogan Motion 8i |
MartinLogan Motion 30i |
| Brand |
MartinLogan |
MartinLogan |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
20-180 watts |
20-200 watts |
| Sensitivity |
89 dB |
91 dB |
| Impedance |
4 ohms |
4 ohms |
| Frequency Response |
70-23k Hz |
65-25k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
1 |
| Woofer Size |
4" |
5.25" |
| Woofer Composition |
poly cone woofers with rigid dust caps |
Aluminum |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1.0 x 1.4" |
1.0 x 1.4" |
| Tweeter Type |
Folded Motion |
Folded Motion |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
400Hz and 2600Hz |
| Firing Direction |
n/a |
rear |
| 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") |
177.0mm (7") |
| Width |
562.0mm (22.1") |
423.0mm (16.7") |
| Depth |
134.0mm (5.3") |
281.0mm (11.1") |
| Weight |
3.86kg (8.5lbs) |
8.18kg (18lbs) |
| Enclosure |
Passive Radiator |
Bass Reflex |
| Finish |
n/a |
MDF/Lacquer |
| Available Colors |
Gloss Black, Matt White, Red Walnut |
White |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
No |
Other |
|
|
| Parts Warranty |
5 Yrs w/ Registration |
5 Years |
| Labor Warranty |
5 Yrs w/ Registration |
5 Years |
Siblings in MartinLogan's Motion series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | B | MartinLogan 30i digs deeper - 65Hz against 70Hz. A subwoofer would even that out. |
| Amplifier needs | B | MartinLogan 30i is more sensitive (91dB vs 89dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (180W vs 200W). |
| Size | depends | MartinLogan 8i is easier to place; MartinLogan 30i is bigger, which usually goes with fuller bass. Your room decides. |
| Cabinet | depends | Passive Radiator vs Ported. |
| Price | A | MartinLogan 8i is cheaper - $450 against $900, about 50% less; arguably a different class. |
A MartinLogan 8i B MartinLogan 30i
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?
The usual trade-off: MartinLogan 30i measures better, MartinLogan 8i costs about about 100% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 70Hz anyway, which makes the cheaper MartinLogan 8i much easier to justify. In a large or open-plan room, MartinLogan 30i has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, MartinLogan 8i 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.