Electrostatic On-Wall

Get off the floor and on the wall with the EFX electrostatic on-wall speaker. This versatile on-wall electrostat is the perfect surround speaker for any MartinLogan home theater system.

$4,399.98 pair
Find a Dealer

Surround Yourself with EFX

MartinLogan is proud to introduce the slim, on-wall EFX™ hybrid electrostatic loudspeaker, featuring XStat™ technology, dramatically reducing cabinet size, yet establishing new standards for efficiency, dynamics and precision.

CLS™ XStat Transducer

Housed within a radical, ultra-ridged extruded aluminum AirFrame™, the EFX's new CLS XStat transducer builds upon the legacy of MartinLogan's electrostatic heritage with the incorporation of advanced vacuum bonding and MicroPerf stat panels, providing even greater efficiency and precision.

Slim On-Wall Profile

If you won't settle for anything but electrostats next to your new flatscreen TV, the EFX is the perfect solution at just 6.5-inches deep. Free up precious floorspace by mounting EFX to your wall with the included wall brackets. The EFX is also the ultimate high-performance home theater surround speaker and complements MartinLogan's entire line of electrostatic loudspeakers. EFX rotates with the pivoting wall bracket to easily focus your surround sound experience.

Advanced Vojtko Filtering

Proprietary Vojtko filtering technology is utilized for EFX's electrostatic transducer. This audiophile quality network, derived from the CLX, is carefully hand-built using precision point-to-point wiring, polypropylene capacitors, massive air-core coils, and a custom wound E-I core transformer—flawlessly preserving micro-acoustic subtleties while effortlessly handling the broadest range of dynamics contained within even the most demanding sonic source.

Custom 5-Way Binding Posts and Low-Voltage Power Supply

MartinLogan's proprietary tool-less binding posts simplify cable connection and management. EFX features custom 5-way binding posts and provide the ultimate level of flexibility for connection and setup. To further simplify setup and cable management, the EFX features a low-voltage DC power supply eliminates the need for a traditional, heavy IEC power cord.



MartinLogan ElectroMotion ESL Loudspeakers Reviewed

"They have great value, a unique sound,and are a true gateway to the journey that is the audiophile hobby."

—Jerry Del Colliano, Future Audiophile
Read the full review»


Specifications are subject to change without notice

Frequency Response

68–22,000 Hz ±3dB

Recommended Amplifier Power

20—300 watts per channel

Horizontal Dispersion


Vertical Dispersion

28" (71cm) line source


90 dB/2.83 volts/meter


6 Ohms, 1.3 @ 20kHz Compatible with 4, 6, or 8 Ohm rated amplifiers.

Crossover Frequency


High Frequency Transducer

XStat™ CLS™ electrostaic transducer » Panel Dimensions: 28" x 8.6" (71 x 22cm) » Radiating Area: 241 in² (1,562 cm² )

Low Frequency Transducer

6.5" (16.5cm) high excursion, fiber cone with extended throw drive assembly; bass reflex


Custom-wound E-I core transformer, air core coils, metal film capacitors


Custom 5-way binding posts

Power Draw

Max: 2W each Standby: <1W each


24.5 lbs. (11.1 kg)


48.8" x 9.4" x 6.5 " (123.9cm x 23.8cm x 16.5cm)

Customer Reviews For EFX

Please, Sign in or Sign up to add comments.


  • Tuesday, August 2, 2022

The stat panel is relatively small, but it still sounds excellent. The frequency response is especially excellent from about 3kHz all the way to 22kHz, with useable response extending well past my measurement setup's threshold of 24kHz. I also have not measured or been able to audibly hear any issues from having this dipole speaker mounted so close to the wall. That makes this an especially excellent surround channel speaker. It will reproduce ambient noises you otherwise wouldn't hear with most box speakers; it takes a decent Beryllium tweeter or the world's greatest soft dome, aluminum or titanium tweeter to keep up with these on the top end. The 6.5" woofer isn't as good as it could be, and it could benefit from a higher order low-pass crossover. It would be much better if it had the aluminum cone, high excursion 6.5" woofer from the Focus C18, and a redesigned the crossover to avoid the midrange from the woofer overpowering the midrange from the stat panel. That said, even though it's not ideal, room correction like ARC Genesis or Dirac Live can easily fix the midrange response issues. That conclusion leads me to the bottom line that these speakers are fairly overpriced for the performance they provide. They should not be more expensive than the ESL, which has a much larger stat panel, cabinet and woofer. I'm looking to have an entirely hybrid-electrostat 5.1 system in a very small room, so I don't have much of a choice but to use these for the surround channels. It's going to be a chore to deal with modifying the crossover, but I will definitely be experimenting with different 6.5" woofers in this speaker.

Michael W.

  • Friday, July 5, 2019

The first ML speaker I owned was the SLM - I was shocked at the incredible sound. I had this same experience going from the SLM to the EFX. I used both as mains for home theater and stereo. Each Martin Logan product is amazing. The EFX sounds like a huge speaker and all the fine details of sound is present. When playing stereo, I had to check my other speakers several times if I was running surround sound... because the sound is so subversive. It wraps around me and can not be pin pointed to a source. Placement is important but not hard to set up - distance apart and the angle towards the listener make a big difference. Not too far apart seems good for my room (8’). The bass is light with this size speaker, of course, but with a subwoofer and proper set up of the audio processor, this can be resolved. It takes a long time to break in. I don’t think mine ever did until I moved and was able to play loudly. I highly recommend.