MartinLogan EFX

A wall-mounted electrostatic hybrid sold as a pair: a 71 cm tall XStat panel and a 16.5 cm bass-reflex woofer in a cabinet 16.5 cm deep. It is conceived as a surround for MartinLogan home cinema systems, yet also works either side of a television.

EFX: an electrostatic for the wall

The EFX is for anyone who wants the sound of an electrostatic panel without giving up floor space. It fixes to the wall on the brackets packed with it, and these pivot, so each speaker can be turned to aim at the listening area. The XStat panel measures 71 x 22 cm, with 1,562 cm² of radiating area, and covers everything above 530 Hz; underneath sits a 16.5 cm woofer with a fibre cone and long-throw motor, reflex loaded. Response runs from 68 Hz to 22 kHz within ±3 dB, sensitivity is 90 dB and nominal impedance 6 ohms, dipping to 1.3 ohms at 20 kHz.

The panel is curved on Curvilinear Line Source lines and mounted in a very stiff AirFrame of extruded aluminium. Its construction uses vacuum bonding and stators with MicroPerf perforation, two choices aimed at higher efficiency and precision. Horizontal dispersion is 30°, while vertically the panel acts as a line source 71 cm tall.

The panel's filter follows the Vojtko topology and is assembled by hand with point-to-point wiring, large coils with air cores, plus a transformer on an E-I core wound to order. Cables attach to posts that tighten without tools. The panel needs power, supplied by an external low-voltage DC unit, which does away with the usual IEC mains lead and makes cable runs on the wall simpler. Maximum draw is 2 W per speaker.

Specifications

• Type: wall-mounted electrostatic hybrid, bass reflex
• Supplied: sold as a pair
• Installation: on the wall, pivoting brackets included
• Frequency range: 68 Hz to 22 kHz (±3 dB)
• Sensitivity: 90 dB (2.83 V at 1 m)
• Impedance: 6 ohms nominal, 1.3 ohms at 20 kHz
• Suggested amplification: 20 to 300 W a channel
• Crossover point: 530 Hz
• Electrostatic panel: XStat CLS, 71 x 22 cm, 1,562 cm² radiating area
• Woofer: 16.5 cm, long-throw fibre cone
• Inputs: hand-tightened posts
• Power: low-voltage DC supply, 2 W maximum per speaker
• Size (height, width, depth): 123.9 x 23.8 x 16.5 cm
• Weight: 11.1 kg each