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.
Turning Unused Space Into Better Bass
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.
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.
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.
Expression ESL 13A Specifications
Specifications are subject to change without notice
|Frequency Response||24–23,000 Hz ±3dB|
|Vertical Dispersion||44″ (112cm) line source|
|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.|
|Room Correction (Bass Section)||Anthem Room Correction (ARC™) ready (Sold Separately)|
|Amplifier||Woofer: 2 x 300 watts/channel (4 ohms), 2 x 600 watts peak|
|Sensitivity||91 dB/2.83 volts/meter|
|Impedance||4 Ohms, 0.7 at 20kHz Compatible with 4, 6, or 8 Ohm rated amplifiers.|
|Recommended Amplifier Power||20—600 watts per channel|
|Components||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
|Lighting||LED intensity control: on, dim, 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.|
|Inputs||AC Power, RJ45 (for ARC), mini USB (for ARC)|
|Power Draw||Idle: < 1W/channel|
|Weight||103 lbs. (46.8 kg)|
|Dimensions||61.5″ x 13.4″ x 27.5 ”|
(156.1cm x 33.9cm x 69.9cm)