If ever there was a speaker line which displayed the ultimate in that elusive quantity known by most audiophiles as ‘Spouse Acceptance Factor (SAP)’, I’m firmly of the opinion that MartinLogan’s range of electrostatic loudspeakers would take the prize. Such is their aesthetic beauty that MartinLogan speakers have appeared in dozens of films and TV series: their outstanding looks and unusual design obviously make them ideal visual fodder for art directors. But looks alone ain’t what this is about, right? We’re about sonics, aren’t we? Well, the US company can proudly boast of having been awarded numerous awards for sonic prowess too: those awards, from some of the most prestigious names in audio, are independent proof that MartinLogan engineers some of the bestsounding speakers available.
The electrostatic principle has been around since the 1950s with the Quad ESL 57 being the granddaddy of the genre so far as full-range, high fidelity reproducers are concerned. Over the years there have been many other companies that have become enamoured of the electrostatic principle and have produced ES speakers that ranged from the moderately successful to those designs that while they are revered, nonetheless sank into obscurity.
MartinLogan, however, is the exception, since it has been steadily and consistently producing ever-evolving examples of the genre since the early 1980s, predominantly based on a design that attempts to address a couple of the inherent weaknesses that dog electrostatic panels; namely dispersion, bass extension and maximum output level. MartinLogan has tackled these issues by engineering electrostatic panels that vary in size, depending on the model, but share a slightly curved profile (MartinLogan refers to this profile as a ‘Curvilinear Line Source’ or ‘CLS’ which is the abbreviation that appears on many-a-model’s nomenclature), therefore dealing with the dispersion issue. By mating these 30-degree dispersion pattern panels with dynamic bass drivers in appropriate enclosures MartinLogan speakers efficiently resolve the question of extension to the bottom octaves.
The brand-new MartinLogan Ethos is from the company’s top tier Reserve Series and is, as you can see from the photograph, a tall see-through tower of electrostatic elegance sitting atop a small real woodveneered enclosure (available in a variety of finishes) housing two bass drivers, a crossover and the circuitry required to deliver the high-voltage charges to the electrostatic panels.
The Ethos’ XStat CLS panel (a direct derivative of the flagship CLX speaker) is a 230mm wide by 1118mm line source driver with a 30-degree dispersion pattern. The panel sits atop the bass enclosure and is slightly angled back to improve its vertical dispersion. The lower enclosure houses a 203mm front-firing aluminium-coned longthrow driver powered by its own 200-watt Class-D amplifier whose frequency response is tailored using 24-bit DSP engine technology. Underneath the Ethos, facing downwards, is another 203mm cone, but this one is made from polypropylene and is not driven by the amplifier. It is instead what’s known as a ‘passive radiator’ or ‘drone cone’ and in effect acts like a bass reflex port, using the otherwise ‘wasted energy’ from the rear of the front-firing driver to extend and augment the deep bass. As with all MartinLogan designs, the crossover is the company’s proprietary ‘Vojtko’ type, the design of which it’s a bit coy about explaining. It has high-quality parts including air-cored coils and polypropylene capacitors.
MartinLogan quotes the frequency response of the Ethos as extending from 34Hz to 23kHz ±3dB and sensitivity as 92dBSPL at one metre for an input of 2.83V. The woofer crosses over to the panel at 375Hz. The impedance is quoted as being 4 but with the typical dip in the high frequencies; in this case down to 0.8 at 20kHz. The Ethos takes a standard speaker-level input from your amplifier—by way of very nice and easy-to-hand-tighten binding posts—and there’s provision for some bass tailoring via a ±10dB level control that operates below 100Hz. Aside from the bass enclosure, the otherwise box-less design means the Ethos is a relatively light speaker, weighing in at only 19kg, making it an easy shuffle around the room. The 1507×273×463mm dimensions makes it a manageable size too.
The Ethos comes with rubber feet for tiled or wooden floors and with beautifullymachined steel spikes for carpeted surfaces. Also worth noting is the very well written and comprehensive manual; it’s packed full with design information and useful set-up suggestions.
During the course of the auditioning sessions I conducted for this review, I hooked the Ethos up to both ‘linear’ and ‘Class-D’ amplifiers, in this case a high-powered Krell integrated amplifier and a flagship NuForce amplifier. Both designs drove the Ethos effortlessly, a testament to the relative insignificance of that high frequency impedance dip given quality amplification. I also found that even in my large auditioning room (approximately 5.5×11m) the Ethos produced oodles of bass power and depth at the ‘0’ position on the bass dial—no need for extra bass level, but if you’re a bass-head, at least you know it’s there!