MartinLogan EFX vs MartinLogan ESL C Comparison

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MartinLogan EFX

Passive Surround | 68-22k Hz

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MartinLogan ESL C

Passive Center Channel | 66-23k Hz

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MartinLogan EFX

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MartinLogan ESL C

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MartinLogan EFX

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MartinLogan ESL C

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MartinLogan EFX vs MartinLogan ESL C Speaker Comparison

In this review, we will be comparing two different types of speakers by MartinLogan. MartinLogan EFX is a Surround speaker whereas the ElectroMotion ESL C is a Center Channel speaker.

Let's have a brief look at the main features of MartinLogan EFX and MartinLogan ESL C first before getting into our more detailed comparison.

Key Specs	MartinLogan EFX	MartinLogan ESL C
Brand	MartinLogan United States · founded 1982	MartinLogan United States · founded 1982
Design	2-way	3-way
Tweeter	Electrostatic	1 x 1-7/16" Folded Motion
Midrange	—	9 x 6.375"
Woofer	6.5" Aluminium	2 x 5.25" high-rigidity aluminum woofers
Frequency response	68-22k Hz	66-23k Hz
Sensitivity	90 dB	89 dB
Impedance	6 ohms	4 ohms
Power range	20-300 watts	20-300 watts
Weight	11.10kg / 24.4lbs	14.55kg / 32lbs
Dimensions (H x W x D)	48-3/4" x 9-3/8" x 6-1/2" 1239.0 x 238.0 x 165.0mm	7-5/8" x 22-7/8" x 16-1/8" 194.0 x 582.0 x 410.0mm

EFX and ElectroMotion ESL C are members of MartinLogan's ElectroMotion series of speakers. Below you can find the loudspeakers from this series.

MartinLogan ElectroMotion Series History

Model	Body	Frequency	Sensitivity	Impedance	Woofer
MartinLogan ESL C	Center Channel	66-23k Hz	89 dB	4Ω	2 x 5.25"
MartinLogan ESL X	Floor-standing	41-22k Hz	91 dB	6Ω	2 x 8"
MartinLogan ESL	Floor-standing	42-22k Hz	91 dB	6Ω	1 x 8"
MartinLogan EFX	Surround	68-22k Hz	90 dB	6Ω	1 x 6.5"
MartinLogan ElectroMotion FX2	Surround	55-25k Hz	93 dB	5Ω	1 x 6.5"

What size room are the MartinLogan EFX and MartinLogan ESL C 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 EFX	MartinLogan ESL C
Near-field	Good	Poor
Small Room	Good	Poor
Mid-size Room	Average	Good
Large Room	Poor	Good
Very Large Room	No way	Average

(* 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

One of the fundamental differences between these two speakers is that EFX is a 2-way design whereas the ElectroMotion ESL C is a 3-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.

MartinLogan EFX

MartinLogan ESL C

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 EFX	MartinLogan ESL C
Driver Setup	2-way	3-way
Tweeter	-inch	1 x 1-7/16-inch
Midrange	-	1 x 9 x 6.375-inch
Woofer	1 x 6.5-inch	2 x 5.25-inch

EFX features a " Electrostatic panel Electrostatic Tweeter and 1 x 6.5" Aluminium Woofer with a Crossover frequency at 530Hz. On the other hand, the ElectroMotion ESL C features a 1 x 1-7/16" Folded Motion Tweeter, a 9 x 6.375" Midrange and 2 x 5.25" high-rigidity aluminum woofers Woofer.

Frequency Response

EFX has a frequency range of 68-22k Hz whereas ElectroMotion ESL C has a frequency range of 66-23k Hz. With a minimum frequency of 66Hz, the ElectroMotion ESL C can go slightly deeper then the EFX's min frequency of 68Hz.

The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Surround class in our database.

Low Frequency

Surround Speakers

EFX

ElectroMotion ESL C

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

EFX is a 6 ohms speaker compared to the ElectroMotion ESL C which has a nominal impedance of 4 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 ElectroMotion ESL C can provide this impedance level.

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

Sensitivity

Surround Speakers

EFX

ElectroMotion ESL C

Min

Average

Median

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.

EFX and ElectroMotion ESL C have the same power range of 20-300 watts.

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.

Amplifier - change this

Distance

Playing as

MartinLogan EFX

MartinLogan ESL C

Input Type and Bi-Amping / Bi-Wiring

EFX features Binding post type posts and ElectroMotion ESL C has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.

MartinLogan ESL C's Binding 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 EFX's and MartinLogan ESL C's external dimensions. MartinLogan EFX has external dimensions of 1239.0 x 238.0 x 165.0mm (48-3/4 x 9-3/8 x 6-1/2inch) whereas MartinLogan ESL C has external dimensions of 194.0 x 582.0 x 410.0mm (7-5/8 x 22-7/8 x 16-1/8inch).

MartinLogan EFX is 344mm narrower and 245mm less deeper than MartinLogan ESL C but it is also 1045mm 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 ESL C needs about 508% more floor or shelf area. MartinLogan ESL C is 245mm deeper, so it stands that much further out from the wall. MartinLogan EFX is 1045mm 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 EFX is approximately 392.7cm² / 60.9inch² and base area of the MartinLogan ESL C is approximately 2386.2cm² / 369.9inch². The EFX requires 84% less surface area than the ElectroMotion ESL C which gives it a small advantage on placement in tight spaces.

What's in the Box of MartinLogan ESL C?

Here are the items that come with the ElectroMotion ESL C:

Center-channel loudspeaker
Grille
AC power supply (attached 10-feet DC cord)
User-feets Manual (En/Fr)
Product Registration Card

Reasons to choose MartinLogan EFX over MartinLogan ElectroMotion ESL C

Sensitivity	90 dB vs 89 dB	Play louder with same amount of amplification power
Nominal Impedance	6 ohms vs 4 ohms	Less selective with amplifiers
Woofer Size	6.5 inches vs 5.25 inches	Larger woofer
Base Surface Area	392cm² vs 2386cm²	Takes less floor space

Reasons to choose MartinLogan ElectroMotion ESL C over MartinLogan EFX

Driver Setup	3-way vs 2-way	Have a dedicated mid-range driver
Number of Woofers	2 vs 1	More woofers
Low Frequency Response	66 Hz vs 68 Hz	Generates deeper bass
High Frequency Response	23k Hz vs 22k Hz	Generates higher frequency
Height	194mm vs 1239mm	Easier to fit in smaller spaces
Price per pair*	1700USD vs 4400USD	costs less (*prices may change depending on the seller, location and time)

MartinLogan EFX vs MartinLogan ESL C Specs Table

Detailed comparison of specifications

General	MartinLogan EFX	MartinLogan ElectroMotion ESL C
Brand	MartinLogan	MartinLogan
Speaker Type	Surround speaker	Center channel speaker
Power Range	20-300 watts	20-300 watts
Sensitivity	90 dB	89 dB
Impedance	6 ohms	4 ohms
Frequency Response	68-22k Hz	66-23k Hz
Drivers
Woofer Quantity	1	2
Woofer Size	6.5"	5.25"
Woofer Composition	Aluminium	high-rigidity aluminum woofers
Tweeter Size	-	1 x 1-7/16"
Tweeter Type	Electrostatic	Folded Motion
Aimable Tweeter	No	No
Midrange Driver	No	9 x 6.375"
Crossover Frequency	530Hz	n/a
Suggested Break-in Period	n/a	Allow 72 hours of break-in at 90 dB
Physical Specs
Height	1239.0mm (48.8")	194.0mm (7.6")
Width	238.0mm (9.4")	582.0mm (22.9")
Depth	165.0mm (6.5")	410.0mm (16.1")
Weight	11.10kg (24.4lbs)	14.55kg (32lbs)
Enclosure	Dipole	Passive Radiator
Available Colors	n/a	Black
Grille	Yes	Yes
Moisture Resistancy	No	No
Connections
Biamp Inputs	No	n/a
Other
Parts Warranty		5 Yrs w/ Registration
Labor Warranty		5 Yrs w/ Registration

Verdict

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

Area	Better	Why
Bass	evenly matched	Much the same reach (68Hz vs 66Hz).
Amplifier needs	evenly matched	Similar sensitivity (90dB vs 89dB) - both want much the same power.
Amplifier match	A	MartinLogan EFX is the easier load at 6 ohms; the other is 4 ohms and wants an amplifier rated for it.
Headroom	evenly matched	Similar power handling (300W vs 300W).
Size	depends	Similar cabinet size - neither is easier to fit.
Type	depends	A Passive Surround against a Passive Center Channel - a different job rather than a better one.
Cabinet	depends	Dipole vs Passive Radiator.
Price	B	MartinLogan ESL C is cheaper - $1,700 against $4,400, about 61% less; arguably a different class.

A MartinLogan EFX B MartinLogan ESL C
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 EFX is ahead, but only on 1 of the measured areas, and it costs about 2.6x the price. That is a lot of money for a narrow margin on paper - MartinLogan ESL C looks like the sensible buy unless something else about the MartinLogan EFX appeals to you. Match it to your room: we rate MartinLogan EFX the better fit for near-field listening and a small room, and MartinLogan ESL C for a mid-size room and a large room. If your amplifier is modest, vintage or valve-based, MartinLogan EFX 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.