From Martin Logan website:
Classic ESL 9
A masterpiece doesn’t just inspire emotions. It changes the way you feel, and it sticks with you long after you’ve left the art gallery or the concert hall. It’s considered a masterpiece precisely because of its ability to alter something inside you. Once you experience it, you’ll never be the same. Enjoying a masterpiece in your own home is something to aspire to.
Consider the Classic ESL 9 your ticket to a life-changing experience with a masterpiece of audio performance. You will never be the same.
A Classic Masterpiece of Sound Reproduction
MartinLogan unveils the Classic ESL 9, its newest modern Masterpiece. All the familiar elements of MartinLogan’s flagship ESL series are here, with some revolutionary refinements. The heart of this exceptional loudspeaker is its 9.2-inch-wide Curvilinear Line Source (CLS) XStat vacuum-bonded electrostatic transducer. Advanced MicroPerf stator technology reveals more of the diaphragm surface area than any other electrostatic panel in this size class, efficiently increasing the narrow panel’s output. Ultra-rigid AirFrame Blade construction reduces performance-robbing vibrations, its shape creating an expressive alignment with the woofer cabinet. Deep bass is rendered with unflinching accuracy and authority by dual 8-inch low-distortion, high-excursion aluminum cone woofers in a beautifully sculpted enclosure.
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. A reinforced electrostatic panel with rigid ClearSpar™ spacers, keeping an exact level of tension on the vacuum-bonded diaphragm without obscuring the beautiful see-through design. Add to these the slender, pointed-arrow design of the new AirFrame™ Blade construction and the result is a powerfully evocative composition creating a harmonious connection between the panel and its woofer cabinet.
Classic Elements, Experienced In a New Way: Advanced MicroPerf stator technology, which allows for almost twice the exposed electrostatic diaphragm surface as a traditional electrostatic panel of the same size. A reinforced electrostatic panel with rigid ClearSpar™ spacers, keeping an exact level of tension on the vacuum-bonded diaphragm without obscuring the beautiful see-through design. Add to these the slender, pointed-arrow design of the new AirFrame™ Blade construction and the result is a powerfully evocative composition creating a harmonious connection between the panel and its woofer cabinet.
Now notice some refinements: We have reinvented the Classic ESL 9 woofer section. We use two 8-inch laser-engineered low-distortion aluminum cone woofers, balanced in an opposing array, one forward- and one rear-firing. This design greatly reduces cabinet vibrations inherent in same-direction woofer positioning, specifically in the 34Hz to 100Hz range for uniform frequency response resulting in realistic bass effects you can feel.
New Ultra-Rigid AirFrame Blade Design
Classic ESL 9 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.
Big, Well-Blended Bass Performance
Rounding out the dynamic performance of this Masterpiece is a passive pair of high-excursion 8-inch laser-engineered aluminum cone woofers custom designed by MartinLogan’s in-house engineering team. This efficient, cast basket woofer design improves cone suspension and the magnetic flux field, maximizing response time, to produce truly profound bass output (down to 34Hz) with vanishingly low distortion.
The woofers are balanced in an opposing array, one forward- and one rear-firing. This design greatly reduces cabinet vibrations inherent in same-direction woofer positioning, specifically in the 34Hz to 100Hz range. Roll-off characteristics for this opposing woofer array are further optimized for a realistically coherent bass wave form. In addition, we’ve tuned the rear-firing woofer to minimize near-wall interactions, perfectly complementing the dipole nature of the electrostatic panel. Bass performance from this configuration is accurate, musical and utterly lifelike.
A flared, ultra-low turbulence rear-firing slotted bass port is integral to the design of the enclosure, providing an extra layer of rigid internal bracing and increasing deep bass output with no added port noise.
Bi-wirable Tool-less Binding Posts and Low-Voltage Power Supply
MartinLogan's proprietary tool-less binding posts simplify cable connection and management. Two sets are supplied—one connected to the electrostatic panel and the other feeding the woofer. Listeners can choose to vertically/horizontally bi-amp the Classic ESL 9, or use jumper clips between the binding post sets for a single wire-connection. Classic ESL 9 features bi-wirable binding posts and provide the ultimate level of flexibility for connection and setup. To further simplify setup and cable management, Classic ESL 9 features a low-voltage DC power supply eliminates the need for a traditional, heavy IEC power cord.
Precision-Built Advanced-Topology Vojtko Crossover
Control is key in the production of a Masterpiece. (Just ask Michelangelo.) Control in the Classic ESL 9 is provided by the advanced Vojtko-voiced crossover. Carefully hand-built using only the finest metallized film capacitors, air-core coils, and low DCR steel laminate coils, the crossover employs MartinLogan’s proprietary Vojtko topology for vanishingly low distortion and seamless driver/ESL integration. This precision-tuned network excels at preserving and reproducing even the most microscopic sonic nuances, while ably handling the full dynamics of any source. The Classic ESL 9 is engineered to work well with practically any type of electronics. MartinLogan’s state-of-the-art electrical interface engineering ensures an absolutely transparent link from your amplifier to the electrostatic panel and woofer array. This produces sound of unparalleled purity, precision, clarity, and openness.
Like all of the loudspeakers in the Masterpiece Series, and like any true masterpiece, when you experience the realistically transparent performance of the Classic ESL 9, you will be changed by it.
Turning Unused Space Into Better Bass
The depth of Masterpiece Series speaker cabinets was carefully chosen to maximize benefits of advanced bass technologies, providing a level of low-frequency precision that is truly unique.
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).
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.