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.
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.
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.
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.
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.
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.
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 24Hz. 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.
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.