About the MartinLogan Masterpiece Classic ESL 9
Impressive detail and an expansive soundstage
The MartinLogan Masterpiece Classic ESL 9 is a perfect blend of high-end form and function.
Impressive detail and an expansive soundstage
When MartinLogan demonstrated a pair of Masterpiece Classic ESL 9 speakers at Crutchfield HQ, I made sure to look around the room. As I expected, I saw telltale signs that our veteran writers and Advisors were impressed: they exchanged significant looks, arched a single eyebrow, or mouthed "wow" to a neighbor. Nobody spoke out loud, which was good — I wanted my ears to focus on the crystalline detail, musical bass, and room-spanning soundstage the Classics were producing.
Efficient, elegant electrostatic panel design
If you're used to traditional woofers and tweeters, welcome to something different, and very cool. Instead of domes and cones, this speaker uses an electrostatic panel to reproduce treble and midrange. It's an ultra-thin diaphragm that's suspended between two electrically charged perforated steel plates. The diaphragm's light weight allows it to move back and forth between the plates thousands of times a second, creating incredibly detailed, lifelike sound.
The ESL 9's curved panel is a perfect blend of high-end form and function. Efficient MicroPerf technology exposes more of the electrostatic diaphragm surface, allowing the speaker to create a wide soundstage from a relatively narrow panel. Ultra-rigid AirFrame Blade construction — precision manufactured from an aerospace-grade extruded aluminum alloy — reduces vibrations and enhances imaging, sonic detail, and accuracy.
Refined woofer array
Previous speakers in the ESL line have offered powerful bass, but MartinLogan made some important tweaks to the Classic ESL 9. The speaker's cabinet houses two 8" laser-engineered low-distortion aluminum cone woofers in an opposing array — one facing forward and one rear-firing. It's a balanced design that greatly reduces cabinet vibrations that can occur when both woofers face forward.
The first time I heard MartinLogan electrostatic speakers
I grew up in Lawrence, Kansas, which also happens to be MartinLogan's hometown. As a student at the University of Kansas, I had a part-time job at the on-campus public radio station, which gave me an early opportunity to learn about music and electronics. I clearly remember one special occasion circa 1990, when one of the station's benefactors — a retired physician and professor emeritus — invited some of the staff to his home.
When I walked into his well-appointed living room, my eyes were drawn to a pair of relatively tall structures I could not identify. I said "what are those?" in an awestruck voice. They were, of course, a pair of MartinLogan's early electrostatic speakers. Our host — a classical music aficionado — proudly put them through their paces, playing soaring arias and soulful string quartet pieces. It was my first exposure to audiophile-quality speakers, let alone electrostatic technology, and I was floored.
That memory of game-changing sound came flooding back when MartinLogan auditioned the Classic ESL 9 at Crutchfield HQ. The sound is even more extraordinary today, as the company has applied the technological advances of the intervening decades to their time-tested speaker design. To my mind, the Classic lives up to its name: it's modern in its look and sound, with ample respect for MartinLogan's legacy.
Unique crossover network
MartinLogan speakers feature proprietary Vojtko™ crossovers, named after thecompany's chief audio technologist, Joe Vojtko. "A Vojtko crossover isn't so much a set of design requirements as it is a philosophy," the company explains. Each speaker's drivers are carefully selected or designed to operate within an intentional frequency range and specific performance parameters. That allows the crossover networks — built from high-quality capacitors and resistors — to be clean and uncomplicated.
- matched pair of speakers
- 44" x 9-1/4" CLS™ (Curvilinear Line Source) XStat™ electrostatic transducer for wide sound dispersion, excellent clarity, and low distortion
- ultra-rigid AirFrame Blade construction reduces vibrations that can harm performance
- efficient MicroPerf stator technology increases the panel's output
- two 8" high-excursion aluminum cone woofers in opposing array
- bass-reflex woofer enclosure with rear-firing slot port
- external low-voltage DC power supply (included) requires AC outlet connection to energize electrostatic panel
- proprietary high-performance Vojtko™ crossover network
- frequency response: 34-23,000 Hz (±3dB)
- sensitivity: 90 dB
- impedance: 4 ohms (compatible with 4, 6, or 8 ohm rated amplifiers)
- recommended amplifier power: 20-400 watts
- includes adjustable floor spikes
- custom 5-way binding posts allow for secure wire connections
- bi-amp and bi-wire capable
Dimensions and warranty:
- 10-7/16"W x 59-13/16"H x 25-7/16"D (each speaker)
- weight: 78 lbs. (each speaker)
- warranty: 5 years (with product registration)
What's in the box:
- 2 Floorstanding hybrid electrostatic loudspeakers
- 2 AC power adapters (w/ attached 10' DC cord)
- 2 Grilles
- 8 Spike Feet
- User's Manual
- Product Registration Card
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More details on the MartinLogan Masterpiece Classic ESL 9
Features & specs
|Tweeter Size (inches)||9.2 x 44|
|Midrange Size (inches)||N/A|
|Woofer Size (inches)||8|
|Built-in Powered Sub||No|
|Dolby Atmos Drivers||No|
|Connector Type||Binding post|
|Parts Warranty||5 Years w/ Registration|
|Labor Warranty||5 Years w/ Registration|
|Frequency Response||34-23k Hz|
|Subwoofer Amp Power||---|
Electrostatic Technology (How it Works): Where traditional loudspeaker technology incorporate cones, domes, diaphragms, and ribbons that are moved with magnetism, electrostatic loudspeakers employ charged electrons attracting and repelling each other. An electrostatic transducer consists of three pieces; stators, the diaphragm, and spacers. The diaphragm is what actually moves to excite the air and create music. The stator's job is to remain stationary and to provide a reference point for the moving diaphragm. The spacers provide the diaphragm with a fixed distance in which to move between the stators. As your amplifier sends music signals to an electrostatic speaker, these signals are changed into two high-voltage signals that are equal in strength but opposite in polarity. These high voltage signals are then applied to the stators. The resulting electrostatic field, created by the opposing high voltage on the stators, works simultaneously with and against the diaphragm, consequently moving it back and forth, producing music. This technique is known as push-pull operation and is a major contributor to the sonic purity of the electrostatic concept due to its exceptional linearity and low distortion.
Hybrid Electrostatic Speaker: The MartinLogan Classic ESL 9 is a hybrid electrostatic loudspeaker that features a XStat CLS electrostatic transducer panel, an optimized Vojtko crossover, and two passive 8" woofers. Electrostatic panels are perfect for reproducing high, midrange, and midbass frequencies. However, both the size and the power requirements of deep bass frequencies are best served by traditional cone woofers. A phase and amplitude optimized Vojtko crossover (380Hz) ensures a seamless transition between the two sound reproduction philosophies. As a result, this speaker offers the best performance for high, mid, and low frequencies.
- Controlled Dispersion Sound Radiation: A key attribute of the Classic ESL 9 is its naturally dipolar radiation pattern. A true dipole, the Classic ESL 9 radiates sound with equal intensity from the front and back of its diaphragm, but the outputs are in opposite phase. As a result, sound waves rippling out toward the sides meet at the speaker's edge and cancel. That and the relatively large size of the Classic ESL 9's electrostatic panel cause output at the sides to be very low relative to that of a conventional loudspeaker, which in turn minimizes side-wall reflections that tend to muddle sonic detail and stereo imaging. While the reduction in output to the sides contributes to the astonishing clarity, the energy reflected off the wall behind the speaker opens up and deepens the sound.
- Full-Range Operation: Another significant advantage of MartinLogan's exclusive electrostatic transducer technology is that no crossover networks are used above 500Hz, because they are not needed. The Classic ESL 9 consists of a single, seamless electrostatic membrane reproducing all frequencies above 500Hz simultaneously. This eliminates the crossover phase aberrations that are associated with traditional tweeter, midrange, and woofer systems. The result is a dramatic improvement in imaging and staging performance.
XStat CLS Transducer: The MartinLogan Classic ESL 9 features a 9.2" (w) x 44" (h) XStat CLS Transducer. This new XStat transducer builds upon the legacy of MartinLogan's electrostatic heritage with the incorporation of a myriad of technology and design innovations including AirFrame Blade Technology, CLS, MicroPerf, Generation 2 Diaphragms, ClearSpars, and Vacuum Bonding.. Through rigorous testing, this curvilinear electrostatic panel has proven itself to be one of the most durable and reliable transducers available today. Fabricated from a custom tool punched high-grade steel, the patented panel is then coated with a special polymer that is applied via a proprietary electrostatic bonding process. This panel assembly houses a membrane just 0.0005" thick. Ruggedly constructed and insulated, the panel is rated to easily handle 20 to 400 watts of power.
- AirFrame Blade Technology: 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. 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 AirFram Blade design enhances imaging, low-level sonic detail, accuracy, and speaker efficiency.
- CLS (Curvilinear Line Source): MartinLogan engineers discovered a simple solution to achieve a smooth pattern of dispersion from a smaller electrostatic transducer without degrading sound quality. By curving the horizontal plane of the electrostatic transducer, a controlled 30° horizontal dispersion pattern could be achieved, yet the purity of the almost massless electrostatic diaphragm remained uncompromised.
- Generation 2 Diaphragm: The diaphragm used in the ElectroMotion ESL 9 XStat transducer employs an extremely sophisticated conductive coating applied to the polymer surface at an atomic level using a plasma bonding process. A proprietary compound is driven into the surface of the polymer film in an oxygen free argon chamber. This process allows extremely uniform surface resistivity characteristics, an optically transparent surface, and a nearly massless diaphragm. This uniform surface resistivity controls the electrostatic charge on the diaphragm surface and regulates its movement.
- MicroPerf Stator: Although stators are the elements of an electrostatic driver that are supposed to stand still, they carry the audio signals that do the work of propelling the diaphragm back and forth to move air and produce sound. Because the stators sandwich the diaphragm between them, they must be perforated to allow sound to pass through. Yet they must also be rigid enough to remain absolutely stationary despite the strong electrostatic forces pushing and pulling at them during operation. MartinLogan's MicroPerf design optimizes this tradeoff by reducing the size of the individual holes and using many more of them than in a traditional electrostatic panel. MicroPerf almost doubles effective diaphragm radiating area without compromising structural integrity. The resulting increase in output capability and efficiency allows the XStat CLS panel to be made much smaller without sacrificing performance and lets you enjoy a substantial leap in bandwidth and dynamics.
- Vacuum Bonding + ClearSpar Spacers: To achieve the power, precision, and strength of the XStat transducer, two insulated high-purity carbon steel stators along with a proprietary plasma bonded diaphragm and ClearSpar spacers are fused into a curved geometry with an aerospace adhesive whose strength exceeds that of welding. MartinLogan's proprietary Vacuum Bonding process guarantees uniform diaphragm tensioning and extremely precise construction tolerances, resulting in precision, linearity and efficiency.
Dual 8" Woofers w/ Ported Cabinet: The MartinLogan Classic ESL 9 uses two 8" 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. Roll-off characteristics for this opposing woofer array are further optimized for realistic coherent bass response. In addition, MartinLogan 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. The 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 low distortion.
Note: When you first begin to play the Classic ESL 9 speaker, it will sound a bit bass shy. This is due to the high-quality, long-life components used in the passive woofer. The custom-made woofer requires approximately 72 hours of break-in at 90 dB (moderate listening levels) before any critical listening. The break-in requirements of the crossover components (and, to a lesser degree, the stator) are equivalent.
ForceForward Bass Reflex Cabinet: The depth of Classic ESL 9 speaker cabinet 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 the opposing woofers, the Classic ESL 9 speaker eliminates problematic bass energy from behind the speakers. A flared, ultra-low turbulence rear-firing slotted bass port is also 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.
Proprietary Vojtko Filtering: To seamlessly blend audio output from the high- and mid-frequency electrostatic panel to the low-frequency woofers the Classic ESL9 features a proprietary Vojtko topology filter utilizing custom air core coil and low DCR steel laminate inductors, polyester film capacitors in series, and low DF electrolytic capacitors in parallel.
Bi-Wirable Binding Post: The Classic ESL 9 features bi-wirable binding posts and provide the ultimate level of flexibility for connection and setup. 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. You can choose to bi-amp the ESL X, or use jumper clips between the binding post sets for a single wire-connection. The binding posts will accept bare wire (16- to 8-gauge), pin-connectors, spade-connectors, and banana plugs (single only).
Low-Voltage DC Power Supply: The Classic ESL 9 speaker uses an external low-voltage power supply to energize its electrostatic panel. The included power supply firmly inserts into the "DC Power In" receptacle on the rear-panel of the speaker and then to an AC wall outlet. The Classic ESL 9 speaker features a signal sensing circuit which will switch the Classic ESL 9 off after a few minutes of no music signal, and requires less than two seconds to recharge the panels when a music signal is present.
Applications: The MartinLogan Classic ESL 9 floor-standing loudspeakers can be used as stereo speakers or home theater front/surround speakers. The Classic ESL 9 speakers are ideal for medium and large rooms.
Placement: The depth of Classic ESL 9 speaker cabinet lends itself to providing the electrostatic panel with adequate distance from the wall, guaranteeing a richly detailed, three-dimensional soundstage. The Classic ESL 9 speaker can be positioned closer to the wall than previous generations of MartinLogan speakers. As a rule of thumb MartinLogan recommends placing the rear of the speaker cabinet no closer to the wall than the diameter of its woofer (which in this case is 8"). Your sitting distance should be further than the distance between the Classic ESL 9 speakers themselves. This will allow you to attain good center imaging and stage width. Generally, it is found that the ideal listening position is with the speakers slightly toed-in so that you are listening to the inner third of the curved transducer section.
Note: The front wall surface ideally should be one long wall without any doors, windows, or other openings. If you have openings, the reflection and bass characteristics from each channel can be different.
Interchangeable Feet: The MartinLogan Classic ESL 9 floor-standing loudspeaker includes four pre-installed rubber feet for tile and hardwood floors. You can remove the rubber feet and install metal spike feet for carpeted flooring. The spike feet are threaded into the base of the speaker and can be adjusted to non-level surfaces.