The ElectroMotion ESL (EM-ESL) represents a brave new direction for electrostatic loudspeaker design. Featuring a full-sized 34-inch tall curvilinear XStat™ electrostatic transducer the new ESL performs more like a mini-flagship than an entry level audiophile speaker. Long time MartinLogan enthusiasts are sure to describe ElectroMotion ESL as the second-coming of the legendary Aerius electrostatic speaker which debuted in 1992 and went on to sell in record numbers. The new ESL, however, boasts 40 percent more radiating surface, a superbly integrated and authoritative bass performance, and a sensitivity rated at 91dB. In addition, the ESL is capable of being effortlessly powered by both receivers and high-end amplifiers alike.

ElectroMotion ESL's XStat electrostatic MicroPerf panel is housed within a radical aluminum and composite AirFrame™ similar to those found on MartinLogan's flagship products. AirFrame technology rigidifies the electrostatic panel without obstructing playable surface area or interfering with ambience enriching dipole sound radiation. At the same time, an AirFrame provides electrical and acoustical isolation, minimizing intermodulated distortion caused by vibration and resonance while enhancing imaging, low-level sonic detail, accuracy, and efficiency. MicroPerf design optimizes the individual holes of The EM-ESL's electrostatic panel. MicroPerf design substantially increases diaphragm radiating area, compared to early generations—without compromising structural integrity. The resulting increase in output capability and efficiency allows The EM-ESL's panel to enjoy a substantial leap in bandwidth and dynamics without growing larger. For example, The EM-ESL's XStat electrostatic panel features 129 square inches of sound radiating surface on both the front and back and a sensitivity of 91dB into 6 Ohms. The Aerius, well received its day, only had 93 square inches and a sensitivity of 89dB into 4 Ohms.

A unique XStat™ transducer was developed for the ElectroMotion ESL to reduce the gauge thickness of the electrostatic panel's steel stators. The reduced gauge does not alter the performance characteristics of the panel. However, as a natural byproduct of tighter build tolerances, it does increase the visual transparency of the panel. The EM-ESL's new XStat panel is so visually transparent it nearly vanishes when you're sitting and listening.

CLS™ XStat™ Transducer

One of MartinLogan's original breakthroughs, CLS™ (Curvilinear Line Source) technology, has been an essential ingredient of every electrostatic loudspeaker we've produced—and the ElectroMotion ESL is no exception. Proprietary manufacturing methods enable construction of electrostatic panels as cylindrical sections. Their gentle horizontal curvature solves the problem of obtaining good high-frequency dispersion from a large radiating surface without compromising overall sound quality or reliability.

Controlled Dispersion Sound Radiation

Another 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 for which electrostats are revered, the energy reflected off the wall behind the speaker opens up and deepens the sound.

Superb Bass Integration

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.

A precise 8-inch high-excursion, perfectly balanced, audiophile grade, doped fiber cone woofer was 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 minimizes response time to achieve remarkably low-distortion approaching that of MartinLogan's award-winning electrostatic panel design.

Technical Specifications

	ElectroMotion ESL X	EFX	ElectroMotion ESL	ElectroMotion ESL C	ElectroMotion C2	ElectroMotion FX2
Frequency Response	41–22,000 Hz ±3dB	68–22,000 Hz ±3dB	42–22,000 Hz ±3dB	66–23,000 Hz ±3dB	55–25,000 Hz ±3dB	55–25,000 Hz ±3dB
Dispersion	30° x 40" (101.6cm) line source	30° x 28" (71cm) line source	30° x 34" (71cm) line source	30° x 6.375" (16cm) line source	80° x 30°	160° x 30°
Sensitivity	91 dB/2.83 volts/meter	90 dB/2.83 volts/meter	91 dB/2.83 volts/meter	89 dB/2.83 volts/meter	94 dB @ 2.83 volts/ meter	93 dB @ 2.83 volts/ meter
Nominal Impedance	6 Ohms, 1.6 @ 20kHz. Compatible with 4, 6 or 8 ohm rated amplifiers.	6 Ohms, 1.3 @ 20kHz. Compatible with 4, 6 or 8 ohm rated amplifiers.	6 Ohms, 1.6 @ 20kHz. Compatible with 4, 6 or 8 ohm rated amplifiers.	4 Ohms. Compatible with 4, 6 or 8 ohm rated amplifiers.	4 Ohms. Compatible with 4, 6 or 8 ohm rated amplifiers.	5 Ohms. Compatible with 4, 6 or 8 ohm rated amplifiers.
Recommended Amplifier Power	20-400 watts per channel	20-300 watts per channel	20-300 watts per channel	20-300 watts per channel	20-250 watts per channel	20-200 watts per channel
Crossover Frequency	400Hz	530Hz	500Hz	600, 3400 Hz	900, 2,300 Hz	2,300Hz
High Frequency Transducer	XStat™ CLS™ electrostaic transducer	XStat™ CLS™ electrostaic transducer	XStat™ CLS™ electrostaic transducer	One 1" x 1.4" (2.6cm x 3.6cm) Folded Motion Transducer with 5.25" x 1.75" (13.3cm x 4.4cm) diaphragm.	One 1.25" × 2.4" (3.2cm × 6.1cm) Folded Motion XT Transducer with 4.5" × 2.75" (11.4cm × 7cm) diaphragm	Two 1.25" × 2.4" (3.2cm × 6.1cm) Folded Motion XT Transducers with 4.5" × 2.75" (11.4cm × 7cm) diaphragm
» Panel Dimensions (HxW)	40" x 8.6" (102cm x 22cm)	28" x 8.6" (71cm x 22cm)	34" x 8.6" (86cm x 22cm)	—	—	—
» Radiating Area	344 in2 ( cm2)	241 in2 ( cm2)	292 in2 ( cm2)	—	—	—
Mid Frequency Transducer	—	—	—	XStat™ CLS™ electrostaic transducer	—	—
» Panel Dimensions (HxW)	—	—	—	6.375" x 23" (16cm x 58cm)	—	—
» Radiating Area	—	—	—	147 in2 ( cm2)	—	—
Low Frequency Driver	Two 8” (20.3 cm) high excursion, high-rigidity paper cones with extended throw driver assembly, non-resonance asymmetrical chamber format, bass reflex	6.5" (16.5cm) high excursion, fiber cone with extended throw drive assembly; bass reflex	8" (20.3cm) high excursion, high-rigidity paper cone with extended throw drive assembly, non-resonance asymmetrical chamber format; bass reflex	Two 5.25" (13.3 cm) high excursion, high-rigidity aluminum cone with extended throw driver assembly, non-resonance asymmetrical chamber format.	Two 5.25" (13.3cm) paper cone with cast aluminum basket. Ported.	6.5" (16.5cm) paper cone with cast aluminum basket. Ported.
Weight	52lbs. (23.6kg) each	24.5lbs. (11.1kg) each	35.5lbs. (16.1kg) each	32lbs. (14.5kg) each	24.5lbs. (11.12kg) each	16lbs. (7.3kg) each
Overall Dimensions (HxWxD)	59.2 x 9.4 x 20.7 (150.3cm x 23.8cm x 52.6cm)	48.8 x 9.4 x 6.5 (123.9cm x 23.8cm x 16.5cm)	52.1 x 9 x 16.3 (132.3cm x 22.9cm x 41.4cm)	7.6 x 22.8 x 16.1 (19.3cm x 57.9cm x 40.9cm)	6.4 x 18.9 x 14.3 (16.4cm x 48.2cm x 36.5cm)	14.9 x 14 x 6.8 (37.9cm x 35.5cm x 17.2cm)