Expression ESL 13A

Premium Performance

Expression ESL 13A is the artful presentation of audio focused solely on intensifying your emotional experience. Featuring a 13-inch (CLS™) XStat™ electrostatic transducer, dual 10-inch PoweredForce Forward™ woofers powered by dual 300-watt Class-D amplifiers, and controlled by a 24-Bit Vojtko™ DSP Engine and ARC™ (Anthem Room Correction).

$17,999.98 pair
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Audio is both real, and imagined. There is the fact of the sound. And there is the feeling that the sound arouses within us.

This feeling is the inspiration behind the new Expression ESL 13A. Like the Expressionist masterpieces, this artful presentation of audio is focused solely on intensifying your emotional experience. It’s a virtually transparent audio performance that transports you to a new landscape of the senses.

The Art of Emotion in Audio

The Expression ESL 13A is part of the Masterpiece Series. It features a dual 10-inch woofer system with ARC-honed performance, for perfectly blended low-frequency response. The groundbreaking integration of this woofer array with MartinLogan’s signature 13-inch wide XStat CLS Transducer, coupled with a powerful dual amplifier section, delivers an expressive and dynamic audio experience, with less coloration. It reveals the pure emotional impact of your audio.

Look at the familiar elements of the classic MartinLogan electrostatic loudspeaker: Advanced MicroPerf stator technology, which allows for almost twice the exposed electrostatic diaphragm surface as a traditional electrostatic panel of the same size. The panel is reinforced with rigid ClearSpar™ spacers, keeping an exact level of tension on the vacuum-bonded diaphragm without obscuring the beautiful see-through design. Add the slender, pointed-arrow design of the new AirFrame™ Blade construction; a powerfully evocative composition creating a harmonious connection between the panel and its woofer cabinet.

Now notice some radical refinements: Inspired by our own breakthrough design, we have reinvented the Expression ESL 13A woofer section, powered by new dual 300-watt Class-D amplifiers, and controlled by a 24-Bit Vojtko™ DSP Engine and ARC™ (Anthem Room Correction).

Using two 10-inch laser-engineered low-distortion aluminum cone woofers in independently enclosed compact chambers, exclusive PoweredForce Forward™ bass alignment technology controls the interaction between the rear-firing woofer and the wall behind that woofer. With smart phase-shifting logic, we minimize the effect that wall has on bass information that might bounce back into the listening room. This uniform frequency response results in realistic bass effects you can feel. It’s one more way MartinLogan innovation improves your listening experience in any room.

Achieving the Laboratory Standard in Your Own Room

In the lab, MartinLogan engineers strive for transparency. Outside the lab, there’s one wildcard our engineers can never account for: Your listening room. The unique size and shape of your listening space (and the size and shape of its contents) can make bass waves do unpredictable things, greatly affecting a speaker’s overall performance.

The Expression ESL 13A integrates exclusive Anthem Room Correction (ARC) technology. By engaging ARC to control the low-frequency curve in relation to the output of the ESL panel (as seen in this graph), you will experience performance on par with MartinLogan’s audio test lab.

ARC measures low-frequency sound output in your room and compares it to optimal response curves that account for spatial anomalies. The advanced algorithms of ARC then effectively remove the anomalies, leaving only the ideal standard: realistically blended, natural-sounding bass performance in your listening space.

By minimizing room interactions with PoweredForce Forward bass technology and the advanced room correction capabilities of ARC, along with its unique synthesis of the ESL and bass sections, the Expression ESL 13A produces perfectly-etched imaging and focus; optimum natural reproduction of sound at lifelike listening levels; and agile, full-range operation in open air.

Clearly, it is this level of ultimate performance that separates the merely excellent from a true masterpiece.

Expression  ESL 13A
Expression  ESL 13A

New Ultra-Rigid AirFrame Blade Design

Expression ESL 13A XStat panels are joined to their speaker cabinets using MartinLogan’s redesigned AirFrame Blade construction, precision manufactured from an aerospace-grade extruded aluminum alloy. This material, and this exclusive manufacturing process, makes the panels extremely rigid.

The bold, forward-moving styling of this AirFrame Blade rail system, narrow and strong in front, broad and forceful from the side, is a modern design statement. It never obstructs playable surface area or interferes with the panel’s dipole sound radiation pattern. It also provides electrical and acoustical isolation, minimizing intermodulation distortion caused by vibration and resonance. The flowing lines emphasize the groundbreaking integration of the panel itself with the compact woofer and amplifier section. The breathtaking AirFrame Blade design enhances imaging, low-level sonic detail, accuracy, and speaker efficiency.

Expression  ESL 13A
Expression  ESL 13A

Curvilinear Line Source (CLS) Electrostatic Panel

CLS technology is an essential ingredient of every electrostatic loudspeaker we produce. Through our proprietary manufacturing method, we have built-in the panel’s gentle horizontal curvature. This unique design enhances the high frequency detail produced by the large radiating surface, without compromising overall sound quality. Notice how the gentle modern curve and perforation pattern gives way to the flat grille of the woofer section.

Controlled Dispersion Sound Radiation

The sound we hear from a loudspeaker is a combination of direct radiation from it to our ears, and reflections off of room surfaces—walls, floor, and ceiling. How our brains integrate this information is far from simple. Depending on the angle of incidence to the ears and the arrival-time difference between direct and reflected sound, reflections can either blur detail and stereo imaging, or enhance the natural impression of depth and openness.

Electrostatic panels, which are true dipole speakers, produce a nearly-ideal controlled dispersion radiation pattern. They send very little sound to the sides, thereby minimizing side-wall reflections, whose short arrival times tend to interfere with the perception of the direct sound. Their strong rear radiation, however, produces a generous amount of natural, ambience-enriching later-arriving mid- and upper register information.

Expression  ESL 13A
Expression  ESL 13A

New  PoweredForce Forward™ Bass Technology

PoweredForce Forward bass technology combines two MartinLogan audio innovations: PoweredForce, which allows small enclosures to accurately produce massive amounts of bass, and ForceForward, which significantly reduces performance-robbing front-wall bass reflections.

PoweredForce Forward bass technology uses an advanced crossover topology with phase-timed woofers to minimize destructive reflected energy. By virtually eliminating front-wall bass reflections and working in tandem with the panel, PoweredForce Forward Bass Technology gives you more placement flexibility, and enhances the true audio realism of your sound source.

Expression  ESL 13A

Turning Unused Space Into Better Bass

Masterpiece Series Cabinet Cut-away

The depth of Masterpiece Series speaker cabinets was carefully chosen to maximize benefits of both PoweredForce and ForceForward technologies, providing powerful bass with extreme detail. Combined with Anthem Room Correction (ARC™), these advanced bass technologies provide a level of low-frequency precision that is truly unique.

Masterpiece Series speaker cabinet dimensions create an ideal relationship between the woofers, cabinet volume, and amplifiers in their PoweredForce woofer systems. By providing ample internal volume for the woofers (two sealed enclosures—one per woofer) along with powerful amplification, Masterpiece Series speakers with powered woofer systems are capable of reaching the lowest registers with authority while preserving bass detail.

With ForceForward bass technology, the farther apart the woofers are from each other the lower in frequency its beneficial effects extend. MartinLogan’s ForceForward technology has solved a problem (found in nearly all speakers) where low bass frequency soundwaves reflect off the wall behind the speakers and interact with the waves traveling towards the listener. These interactions create non-linearity in those frequencies as they arrive at your ears and bass information suffers from both cancelations and excessiveness that is not accurate to the original sound. By selectively adjusting phasing of output from their opposing woofers, powered Masterpiece Series speakers eliminate problematic bass energy from behind the speakers.

ForceForward also simplifies the task of speaker placement by removing bass energy from behind the speaker and creating a uniform bass launch. This allows Masterpiece Series speaker cabinets to go closer to the wall than previous generations of MartinLogan speakers. As a rule of thumb we recommend placing the rear of the speaker cabinet no closer to the wall than the diameter of its woofer (Renaissance ESL 15A: 12-inches, Expression ESL 13A: 10-inches, and Impression ESL 11A and Classic ESL 9: 8-inches). For an added level of control powered Masterpiece Series speakers incorporate two level controls (at 75Hz and 200Hz) to allow for fine tuning of bass integration.

Additionally, due to their dipole nature, electrostatic panels perform best when placed at least 2.5-feet or more from the wall—a distance that is ideal for the front of nearly any high-end speaker, regardless of driver technology. The depth of Masterpiece Series cabinets lends itself to providing electrostatic panels with adequate distance from the wall, guaranteeing a richly detailed, three-dimensional soundstage.

New More Performance, Versatility, and Safety, with WBT Binding Posts

Connect your electronics safely and securely using 5-Way audiophile WBT Binding Posts. Their pure copper connection plate is highly conductive and free from “eddy current” effects. These posts are insulated for shock protection, and fully damped against vibrations. They give you plenty of room for large-gauge professional speaker connections.

Expression  ESL 13A

New Powerful Dual 300-Watt Class-D Amplification with 24-Bit Vojtko™ DSP Engine

The performance of Expression ESL 13A has been reconsidered from the ground up. Taking full advantage of innovations like PoweredForce Forward and ARC Technology, and the integration of the electrostatic panel with the woofer array, required daring thinking about power and efficiency. Our new dual 300-watt amplifiers produce clean power, in a small space, more efficiently than ever before. They enable the effortless delivery of exhilarating dynamic impact, with plenty of overhead. Superior, reliable Class-D technology means there’s virtually no energy lost between the amplifiers and the woofers.

Expression  ESL 13A
MartinLogan’s dedicated in-house design and engineering team created an extremely precise 24-bit Vojtko Digital Signal Processing (DSP) engine to work in conjunction with these powerful new amplifiers. It gives these speakers the ability to deliver detailed low-frequency performance reaching down to 22Hz. Advanced DSP allows complete control and performance optimization over the low pass filters, woofer equalization and limiting functions, all of which are mapped mathematically in the digital domain. Complete control of the signal, along with instant response, huge amounts of clean power, and efficient, integrated performance, paints an original picture of lifelike audio performance.
Expression  ESL 13A

Precision-Built Advanced-Topology Vojtko Crossover

Vojtko Voiced, the advanced crossover and electronics in Expression ESL 13A add enhanced mid-range clarity to this artful composition. Carefully hand-built using only the finest polypropylene capacitors and air-core coils, the crossover employs MartinLogan’s proprietary Vojtko topology for vanishingly low distortion and seamless driver/ESL integration. This precision-tuned network preserves even the most microscopic sonic nuances while handling the full dynamics of any source.

We’ve also considered the signal you will feed your loudspeakers, and have engineered Expression ESL 13A to work well with practically any type of electronics. MartinLogan’s state-of-the-art toroidal transformer and electrical interface engineering ensure an absolutely transparent link from amplifier to electrostatic panel and woofer array. This produces sound of unparalleled purity, precision, clarity, and openness — the next best thing to no speaker at all.


High Expression [RUSSIAN]

"[Translated] MartinLogan Expression ESL 13A delivers a perfectly balanced sound to the listener with an inconspicuous mating of the electrostatic panel and the subwoofer."

—Artem Avatinyan,
Read the full review»

MartinLogan Expression 13A Electrostatic Speaker Review with ARC

"The MartinLogan Expression 13A are the kind of speakers you can easily forget. That is a high compliment for a speaker review. Once in place and supported by proper room treatment, and perhaps a little room correction for ultimate smoothness and ideal SS&I - don't forget about the optional ARC correction built in - I predict most listeners will quickly become comfortable with the inability to find the 13A in the room - they can disappear that completely - and become completely sonically unobtrusive in their systems. The Expression 13A are another example of Electrostatic Magic from the Electrostatic Wizards at MartinLogan. I highly recommend them."

—Wayne Myers,
Read the full review»

MartinLogan Expression ESL 13A Floorstanding Speaker Reviewed

"MartinLogan has hit a home run with the Expression ESL 13A. This speaker improves upon the traditional MartinLogan strong points of transparency and detail and adds a much improved bass section to create a well-rounded, great-sounding speaker. The Expressions are capable of doing the illusive, transporting the listener to the performance."

—Brian Kahn,
Read the full review»

MartinLogan Expression ESL 13A hybrid electrostatic speaker Review

"The MartinLogan Expression ESL13A is a game changer. I have heard better speakers but they are significantly more expensive than the Expression. I never thought I could afford a speaker with this level of performance. "

—Robert Schussel,
Read the full review»

To run Anthem Room Correction (ARC) with your speakers you will need to purchase a PBK or ARC Kit (Please note that MartinLogan Perfect Bass Kit (PBK) microphones are fully compatible with Anthem Room Correction for MartinLogan speakers). Each kit is shipped with a unique microphone.

To download the most up-to-date version of ARC, please click the link below to go directly to Anthem's website.

Get the Latest ARC Software »

System Requirements

ARC Genesis requires an ARC or PBK Microphone, a Mac OS X (10.12+) or Windows (7/8/8.1/10) computer, and an ARC or PBK compatible audio product. One USB port is required. If you are using a laptop computer, check power settings and battery meter before starting to ensure the procedure is not interrupted.


Specifications are subject to change without notice

Frequency Response

24–23,000 Hz ±3dB

Recommended Amplifier Power

20—600 watts per channel

Horizontal Dispersion


Vertical Dispersion

44" (112cm) line source


91 dB/2.83 volts/meter


4 Ohms, 0.7 at 20kHz Compatible with 4, 6, or 8 Ohm rated amplifiers.

Crossover Frequency


High Frequency Transducer

XStat™ CLS™ electrostatic transducer » Panel Dimensions: 44" x 13" (112 x 33cm) » Radiating Area: 572 in² (3,696 cm² )

Low Frequency Transducer

Two 10” (25.4 cm) cast basket, high excursion, rigid aluminium cone and extended throw drive assembly, non-resonance asymmetrical chamber format.


Woofer: 2 x 300 watts/channel (4 ohms), 2 x 600 watts peak

Room Correction (Bass Section)

Anthem Room Correction (ARC™) ready (Sold Separately)


Custom-wound audio transformer, air core coils, polypropylene capacitors. 24-bit DSP based preamplifier (used with woofer amplifier).

Audio Controls

Bass: ±10 dB under 75 Hz Mid-Bass: –2 dB, 0 db, +2 db Light: On, Dim, Off ARC™ Room EQ: On, Off

Signal Inputs

WBT-0703Cu nextgen™ 5-way binding posts feature a filigree signal conductor made from gold plated, nickel free, non- ferromagnetic, pure copper for high conductivity and fully insulated. Free from eddy current effects.


AC Power, RJ45 (for ARC), mini USB (for ARC)

Power Draw

Idle: < 1W/channel Max: 500W/channel


LED intensity control: on, dim, off


103 lbs. (46.8 kg)


61.5" x 13.4" x 27.5 " (156.1cm x 33.9cm x 69.9cm)

Customer Reviews For Expression ESL 13A

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Scott M.

  • Wednesday, April 17, 2019

Two months ago I upgraded from Vista to the Expression. For many months I was trying to convince myself that I'd be happy with Impressions, but within 5 seconds of hearing the Expression demo at the dealer I was hooked! The amazement continues, and continues . . . . These are better in every way! The sweet spot is larger and more forgiving at the boundaries, meaning the edges are a softer blending between sweet and not-as-sweet. The woofer integration is very good indeed! The ARC calibration works very well, simple to execute. I've very recently discovered that tweaking the bass stronger yields major dividends in dynamics, in addition to the expected fullness. This is a new experience for me with electrostatics as I'm used to having less impact from the panel in exchange for clarity, but now I don't feel that I'm lacking anything at all. I've currently positioned the panels about 40" from the front wall, less than where the Vistas were, and they sound brilliant! I will say that the Expressions definitely benefit from wider and taller absorption, partly because they are taller, but also because the sound field is wider. So on the front wall behind the Expressions I've got floor to ceiling absorption panels which are 30" wide and positioned in the first reflection area (between the speakers) more than a foot beyond (towards center) an actual mirrored reflection. Once I did this all rear-wave problems went away! The sound is gorgeous and I simply can't get enough! Sorry for all the exclamation marks, but they are well deserved!! Happy Customer!


  • Wednesday, February 7, 2018

I recently upgraded from the Summit X to the Expression ESL 13A in my media room (previously I had also updated from the Stage X to the Focus center channel several months earlier). This time around I got a custom color instead of a standard finish to closer match my Focus center channel. First let me comment on the quality of the finishing, packaging and workmanship. I saw all this and more first hand at a visit to the Canadian plant so I was not surprised but it was all very well done. Also now that I have purchased several ML products over the years (Summit X, Descent I’s, 212's, CLX Art, Focus, Vanquish) the packing is very good and they have all arrived in great condition. I know packaging is probably not the most talked about topic but we do want our product delivered in good condition. Believe me it’s no accident that they do it’s that good. I must admit I was not an immediate fan of the new look compared to the Summit X's that I had at the time. I was not able to see anything in person until a couple of years ago at Axpona where a pair of 15A's were on display. What I saw on line the new ones just seemed to industrial looking. The much bigger boxy lower end seemed so much bigger then past designs so I was concerned that visually I would not like them as much as the Summit X's. Well let me tell you once I saw them in person I was much impressed with the new design, the much beefier frame and particularly the sound. Being familiar with ML speakers I came to love the clarity of the sound and the new 13A’s just make you smile so much more. The wider panel helps, the much sturdier frame helps but probably the biggest improvement is in the bass section. Yes it’s larger but its sooooo much better. Most likely a combination of the improved amp, the actual enclosure and the calibration software. I was first introduced to the calibration software with my purchase of a couple of 212 subs. It made a tremendous difference in how the bass played in my room and I was not disappointed in how after calibration the bass on the 13A’s sounded – tight, deep and fast just how I like it. I also believe the integration with the top panel is even better with the 13A’s as compared to the Summit X’s. That is saying a lot as I thought the Summit X’s were very well integrated but the new ones are even better. My setup is multichannel not two channel like my Summit X’s were before being moved into the media room. So I don’t have much experience on two channel performance but my gut tells me they will perform nicely and better then the Summit X’s. All I can say to the ML development team is you have hit it out of the park with the new lineup. It was a tough thing to accomplish but it’s nicely done – Visually and Sonically. Not just a small incremental improvement but justifying the new models as they are aptly named.


  • Monday, August 14, 2017

Martin Logan Trainer & Set-Up Expert Joel Lopez - "It's My Passion"
My wife and I purchased Martin Logan Expression 13A loudspeakers from the Magnolia Audio & Design Center in Madison, Wisconsin. Nick Hufford the store manager put me in contact with Joel Lopez at Martin Logan regarding questions I had about rake angle and set up. My first contact was in March of this year. I had already seen several YouTube videos with Mr. Lopez about setting the speakers up. I sent to Mr. Lopez an email containing material from the Cardas website regarding speaker set up. Their calculator was the most helpful. Thank you for contacting Cardas Audio. I recommend using the standard calculator to start. This will help to maximize bass performance. If you also mark the spot for the dipole calculator you could try any location between the two to improve imaging also. Imagine my surprise when there was a message on my cell phone from Mr. Lopez offering to speak to me via telephone regarding my questions and concerns. In the course of that conversation Mr. Lopez offered to come to our home to personally set the speakers up and implement the Anthem Room Correction, a program built into these speakers designed to take the room out of the equation; identifying and removing room nodes and standing waves; essentially allowing the speakers to perform at their best without being compromised by interaction with anomalies caused by the room. Frankly, I was flabbergasted by his offer. He wrote back after reviewing the numbers: When looking at the calculator it looks as though his calculations are correct and also what we would recommend as well. The only downside with using technology for speaker placement is it doesn't take into account things like type of flooring, thickness of sheetrock, type of paint weather flat or gloss, and objects in your room that will absorb or diffuse sound waves. My personal suggestion would be to use the calculator as a starting point for placement but be aware that minor adjustments in placement and or toe in can have a big effect on your overall sound. My offer still stands to come to your home and insure your speakers are performing to the reference level we intended. I simply could not believe my ears. This was personalized service unlike anything I had read about in the industry other than knowing about Peter McGrath of Wilson Audio going to the home of a customer after a sale to set up speakers and of course dealer set up. The set up team from Magnolia did an outstanding job using the results generated by the Cardas calculations. Even before the speakers had 100 hours on them it was hard to imagine how much better the response could be even though I had read reviews which testified to the difference the ARC made. Moreover Mr. Lopez sent instructions for achieving a rake angle of one degree (almost exactly perpendicular to the floor) something I desired, to improve imaging even further so I would have them to give to the install team. He added “Once I get a chance to travel back to Madison, your speakers will have played for the recommended break in period and I can then lend my expertise by making adjustments in placement to squeeze out every ounce of performance as possible.” Mr. Lopez came to our home on July 25th and I played for him 9 selections from vinyl, several from Redbook CD’s and two from an SACD so he would get a good feel for how our system sounded before he started. I thought, somewhat pridefully, that the system sounded very good but was looking forward to witnessing to what degree it could be improved. He felt the soundstage was too small and went to work knowing that my priority, if I had to choose between a large soundstage versus focus, I would choose focus. There was a great deal of speaker movement before the ARC was implemented. He asked my wife to sit in what looked to me to be a very near field listening position and yet it was at the apex of an equilateral triangle. My wife could immediately discern that the new position was much better. Specifically, instruments appeared and sounded a great deal more present and alive than our previous listening position. My wife had to leave to go to the library and when she left I shared that I knew, despite the clear improvement, that she was unhappy about the set up because the seating position was too close, so Mr. Lopez had to start all over again; moving the speakers further apart so the sofa could be further back and still achieve an equilateral triangle. Mr. Lopez started the ARC process and I could clearly see on his laptop the response caused by the room. To say that the frequency response was not linear would be a tremendous understatement. There are degrees of knowing; for years I have read that the room really impacts the sound; take care of room interactions first. The graph on his laptop hardly looked like the frequency response curve of the speakers shown by testing in an anechoic chamber. It is generally taken for granted that it is almost impossible to replicate outstanding results in the real world but the deviation in our living room was not to be believed. When Mr. Lopez was done he asked us to choose a selection from the original ones we played and it was IMMEDIATELY discernible, immediately, as in less than two minutes just how improved was the sound; specifically the entire sound spectrum was balanced! We had not heard the presentation like that before so of course we could not know what we were missing. Choral voices to my ears were even more individuated and defined and yet the presentation became, for lack of a better descriptor, relaxed. It was ironic to me how we could be hearing more information with greater definition and at the same time the presentation was relaxed; not laid back in any way; just relaxed; there was also an effortlessness to the presentation. Mr. Lopez’s experience (he has been with Martin Logan since 2002) cannot be underestimated; the software did not do the work; it was Mr. Lopez’s implementation, that achieved such an accomplished result. In that sense what took place can be described as art, assisted by technology; Mr. Lopez’s artistry was evident as was his craft, and make no mistake it was craft too. The speakers were tilted a bit to the right and left, meaning from side to side respectively for each speaker and he worked tirelessly to make the lack of perpendicularity disappear. I am guessing most people would have been content to leave them as they were. Mr. Lopez said “we are seeking perfection.” I said “I am sorry you are working so hard” and he immediately and yet casually replied “it’s my passion!” What more could I have asked for “it’s my passion” says it all; how many people do you meet that can claim the work they do is their passion? Martin Logan is lucky to have him because he is insuring customer allegiance one at a time; the old fashioned way, via unparalleled dedication to results. In the interest of clarity I want to emphasize that Martin Logan speakers are not finicky or difficult to set up; they are great from the get go, but with the extra attention comes extra-ordinary, extraordinary results. Since Mr. Lopez cannot be cloned, owners would do well to inquire regarding his availability, since his primary responsibility is training dealership personnel.