Electrostatic Technology (How it Works):
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 ElectroMotion ESL is a hybrid electrostatic loudspeaker
that features a XStat CLS electrostatic transducer panel, an optimized Vojtko
crossover, and a passive 8" woofer. 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 (500Hz) ensures a
seamless transition between the two sound reproduction philosophies. As a
result, this speaker offers the best performance for high, mid, and low
XStat CLS Transducer: The MartinLogan ElectroMotion ESL features a
8.6" (w) x 34" (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 CLS, MicroPerf, Generation 2 Diaphragms,
ClearSpars, Vacuum Bonding, and AirFrame technology. 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 300 watts of power.
- 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 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
- AirFrame Technology: The XStat CLS panel is secured to
speaker cabinet using MartinLogan's AirFrame technology. The extruded
aluminum and composite AirFrame makes
the panel extremely rigid while maximizing playable surface area and dipole
sound radiation. At the same time, it provides electrical and acoustical
isolation, minimizing intermodulation distortion caused by vibration and
resonance. Overall, AirFrame technology enhances imaging, low-level sonic detail,
accuracy, and efficiency.
Controlled Dispersion Sound Radiation: A key attribute of the ElectroMotion ESL is its naturally dipolar radiation pattern. A true dipole, the EM-ESL 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 ElectroMotion ESL'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 ElectroMotion ESL 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.
Passive 8" Woofer w/ Ported Cabinet: A precise 8"
high-excursion, perfectly balanced, audiophile grade, doped-fiber cone woofer
has been custom designed exclusively for The EM-ESL by MartinLogan's in-house
engineering team. This woofer precisely optimizes cone suspension and magnetic
flux field to produce high levels of bass output and simultaneous precise
midrange. The custom woofer's rigid light-weight diaphragm eliminates cone
flexure and maximizes response time to achieve remarkably low-distortion. The 8"
woofer is housed in a non-resonant asymmetrical cabinet with a down-firing bass
port for additional bass extension.
Note: When you first begin to play the ElectroMotion ESL 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.
Proprietary Vojtko Filtering: To seamlessly blend audio
output from the high- and mid-frequency electrostatic panel to the low-frequency
woofer the ElectroMotion ESL 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.
Spring-Post Connectors: The ElectroMotion ESL features two
spring-post connectors to attach your speaker wire. The spring-posts will accept
bare wire (16- to 10-gauge), pin-connectors, and banana plugs (single only).
Low-Voltage DC Power Supply: The ElectroMotion ESL 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 ElectroMotion ESL speaker features a signal
sensing circuit which will switch the ElectroMotion ESL 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.
- Input: AC 100-240V~50/60Hz,
- Output: DC 15V, 0.4A
Applications: The MartinLogan ElectroMotion ESL floor-standing speakers can be
used as stereo speakers or home theater front/surround speakers. The ElectroMotion ESL
speakers are ideal for medium and small rooms.
Placement: The ElectroMotion ESL speaker should be placed approximately 2' to 3'
from the front wall (the wall in front of the listening position) and about 2'
from the side walls. Your sitting distance should be further than the distance
between the ElectroMotion ESL 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 Theos floor-standing
loudspeaker includes four pre-installed rubber feet for tile and hardwood
floors. You can remove the rubber tip from the pre-installed feet to reveal four
metal spiked feet for carpeted flooring. The feet are threaded into the base of
the speaker and can be adjusted to non-level surfaces.