In this review, we will be comparing Motion 8i and ES35, two Passive Center Channel speakers from MartinLogan and Polk Audio.
Let's have a brief look at the main features
of MartinLogan 8i and Polk ES35 first before getting into our more
detailed comparison.
| Key Specs | MartinLogan 8i | Polk ES35 |
|---|
| Brand | MartinLogan
United States · founded 1982 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1.0 x 1.4" Folded Motion | 1" High-res dome |
|---|
| Woofer | 2 x 4" poly cone woofers with rigid dust caps | 6 x 3" mica-reinforced polypropylene Dynamic Balance |
|---|
| Frequency response | 70-23k Hz | 66-40k Hz |
|---|
| Sensitivity | 89 dB | 89 dB |
|---|
| Impedance | 4 ohms | 8 ohms |
|---|
| Power range | 20-180 watts | 20-150 watts |
|---|
| Weight | 3.86kg / 8.5lbs | 6.36kg / 14lbs |
|---|
| 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 | 4-3/16" x 24-7/16" x 6-1/16"
107.0 x 621.0 x 154.0mm |
|---|
What size room are the MartinLogan 8i and Polk ES35 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 |
Polk ES35 |
| 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 ES35 are 2-way speakers.
MartinLogan 8iPolk ES35
TweeterWoofer
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 |
Polk ES35 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.0 x 1.4-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 4-inch
|
6 x 3-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 ES35 features a 1" Terylene High-res dome Tweeter and 6 x 3" mica-reinforced polypropylene Dynamic Balance Woofer.
Frequency Response
Motion 8i has a frequency range of 70-23k Hz whereas ES35 has a frequency range of 66-40k Hz. With a minimum frequency of 66Hz, the ES35 can go slightly deeper then 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 is a 4 ohms speaker compared to the ES35 which has a nominal impedance of 8 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 ES35 has a max power handling value of 150 watts RMS, 30 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 5-Way post type posts and ES35 has a 5-Way post type posts. None of these speakers feature bi-amping/bi-wiring.
MartinLogan 8i's Spring post terminals
Polk ES35's 5-Way post terminals
Polk ES35 Port
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 Polk ES35'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 Polk ES35 has external dimensions of 107.0 x 621.0 x 154.0mm (4-3/16 x 24-7/16 x 6-1/16inch).
MartinLogan 8i is 59mm narrower and 20mm less deeper than Polk ES35 but it is also 35mm 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 8i is approximately 753.1cm2 / 116.7inch2 and base area of the Polk ES35 is approximately 956.3cm2 / 148.2inch2. The Motion 8i requires 21% less surface area than the ES35 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 Polk ES35 weighs 6.36kg / 14lbs. This makes the ES35 65% heavier than the Motion 8i.
Here is a comparison of how Motion 8i and ES35'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 Polk ES35?
Here are the items that come with the ES35:
- LCR loudspeaker
- Grille (attached)
- 4 Self-adhesive rubber feet
- Wall-mount template
- Owners Manual
- Online Product Registration
 Max Input Power |
180 watts
vs
150 watts
|
Handle more power from your amplifier |
 Woofer Size |
4 inches
vs
3 inches
|
Larger woofer |
 Base Surface Area |
753cm2
vs
956cm2
|
Takes less floor space |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
|
Number of Woofers |
6
vs
2
|
More woofers |
|
Low Frequency Response |
66 Hz
vs
70 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
23k Hz
|
Generates higher frequency |
 Height |
107mm
vs
142mm
|
Easier to fit in smaller spaces |
 Price per pair* |
399USD
vs
450USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
MartinLogan Motion 8i |
Polk Audio Signature Elite ES35 |
| Brand |
MartinLogan |
Polk Audio |
| Speaker Type |
Center channel speaker |
Low-profile center channel speaker |
| Power Range |
20-180 watts |
20-150 watts |
| Sensitivity |
89 dB |
89 dB |
| Impedance |
4 ohms |
8 ohms |
| Frequency Response |
70-23k Hz |
66-40k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
6 |
| Woofer Size |
4" |
3" |
| Woofer Composition |
poly cone woofers with rigid dust caps |
mica-reinforced polypropylene Dynamic Balance |
| Tweeter Size |
1.0 x 1.4" |
1" |
| Tweeter Type |
Folded Motion |
High-res dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
rear |
| Suggested Break-in Period |
Allow 72 hours of break-in at 90 dB |
n/a |
Physical Specs |
|
|
| Height |
142.0mm (5.6") |
107.0mm (4.2") |
| Width |
562.0mm (22.1") |
621.0mm (24.4") |
| Depth |
134.0mm (5.3") |
154.0mm (6.1") |
| Weight |
3.86kg (8.5lbs) |
6.36kg (14lbs) |
| Enclosure |
Passive Radiator |
Bass Reflex |
| Finish |
n/a |
MDF, Wood-grain vinyl |
| Available Colors |
Gloss Black, Matt White, Red Walnut |
Black, Walnut, White |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Yrs w/ Registration |
5 Years |
| Labor Warranty |
5 Yrs w/ Registration |
5 Years |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass | B | Polk ES35 digs deeper - 66Hz against 70Hz. A subwoofer would even that out. |
| Amplifier needs | evenly matched | Similar sensitivity (89dB vs 89dB) - both want much the same power. |
| Amplifier match | B | Polk ES35 is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | evenly matched | Similar power handling (180W vs 150W). |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Cabinet | depends | Passive Radiator vs Ported. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. MartinLogan 8i sits in a wider range (18 models), so a matched surround system is easier later. |
| Price | B | Polk ES35 is cheaper - $399 against $450, about 11% less. |
A MartinLogan 8i B Polk ES35
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?
Polk ES35 is the easier recommendation: it leads on most of the measured areas and costs less. Take MartinLogan 8i if its size, looks or fit in your room suit you better. If your amplifier is modest, vintage or valve-based, Polk ES35 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.