MARTIN LOGAN ESL13A Expression

I felt that the ESL 13A Expressions favored the width of soundstage to its depth. The lateral imaging precision was clearly supported by minimized side reflections - with good recordings, like those from Chesky Records, the Martin Logan threw wall-to-wall sonic pictures. The depth remained confined to a relatively narrow sweet spot, however. When I moved few inches to either side the imaging magic was partially lost. The producer acknowledges ca 30° radiation angle and this was what I heard. Also I wrestled a bit with vertical imaging which was due to conceptual differences of dynamic low end unit and electrostatic top end panel. Instruments and vocalists were split into two parts - bodies, mass, chests and size were floating over floor, whereas voices, strings, resonances and higher harmonics were coming from the eye level. The louder I played the more this split personality was prominent. I believe that ESL 13A are not easy speakers to place without the Anthem ARC equalization system that helps balance the sound in a listening room.

The Anthem ARC is a proprietary digital signal processing software that works with a special calibration microphone and a PC or iOS device. The development of the DSP system was conducted in conjunction with the National Research Council of Canada (this institution is used by Soundstage! for equipment lab analysis, for example). Each ARC Kit consists of a calibrated microphone with a stand and a cable, plus a downloadable ARC software pack. Plug the kit’s microphone into your computer and into the Martin Logan ESL 13A (RJ45 ethernet or mini-USB socket for smartphone control), place the microphone at each of the listening positions in your room (a minimum of five, maximum of ten), and allow ARC to take a sound sample from each location. The proprietary ARC software measures the difference between the speaker’s ideal lab-standard response, and their real-world performance in your room. After that the ARC equalizes crossover curves so that the performance of the speakers in your room was close to the ideal lab standard.