Floorstanding loudspeakers — Martin Logan ElectroMotion ESL

The ElectroMotion ESL, often shortened to EM-ESL, is the entry point to MartinLogan's hybrid electrostatic floorstanders, aimed at both 2-channel music systems and multi-channel home theatre. MartinLogan describes it as a successor in spirit to the Aerius, an electrostatic model that debuted in 1992. The current list price is USD 2,799.98 per pair, in Satin Black or Gloss Black.

Key specs that matter

MartinLogan rates the EM-ESL from 42 Hz to 22,000 Hz within 3 dB. Sensitivity is 91 dB at 2.83 V and 1 m, and nominal impedance is 6 ohms, dropping to 1.6 ohms at 20 kHz. MartinLogan recommends 20 to 300 W per channel. The crossover frequency is 500 Hz. The XStat CLS panel stands 86 cm tall and 22 cm wide with a radiating area of 1,892 cm2, giving a 30 degree horizontal dispersion. Each speaker weighs 16.1 kg and measures 132.3 x 22.9 x 41.4 cm.

Engineering and use context

Compared with the Aerius, the panel offers 40 percent more radiating surface, and the older model was rated at 89 dB into 4 ohms. For this speaker, MartinLogan developed a version of the XStat transducer with thinner-gauge steel stators, which leaves the performance unchanged but lets more light pass through the panel. MicroPerf hole design raises diaphragm area without weakening the structure, and the panel sits in an aluminium and composite AirFrame. As a true dipole, the panel radiates front and back in opposite phase, so output toward the side walls is low. A single 8-inch high-excursion woofer with a high-rigidity paper cone uses a ported bass reflex alignment, mounted in a non-resonant asymmetrical chamber, with an extended throw drive assembly. The Vojtko filter combines air-core coils and large steel laminate inductors with polyester film capacitors in series and low DF electrolytic capacitors in parallel, plus a custom-wound audio transformer.

Pairing

According to MartinLogan, the EM-ESL can be driven by AV receivers as well as by high-end amplifiers, and is compatible with amplifiers rated for 4, 6 or 8 ohms. Push-style terminals with curved inserts accept bare wire, and removable rubber end caps expose banana jacks. Supplied 3/8-16 ETC spikes help stability on thick carpet and come with rubber caps for hard floors.

Alternatives

For a larger panel in a passive design, MartinLogan offers the Classic ESL 9 with a 23 cm wide XStat CLS transducer and two 8-inch aluminium cone woofers.