The aesthetic beauty of MartinLogan’s electrostatic speakers is such that they have appeared in dozens of films and TV series. Their outstanding looks and unusual design make them desirable visual fodder for art directors, and there’s every chance of them achieving that elusive quality known by most audiophiles as ‘Spouse Acceptance Factor’ (SAP).

But of course we also need solid sonics, audio pictures to go with the visual ones. Happily the US company can boast numerous awards for sonic prowess too, including our own Sound+Image 2012 Award for Stereo Speakers of the Year over $5000, which went to this very model — independent proof that MartinLogan engineers some of the best-sounding speakers available.

The electrostatic principle has been around since the 1950s with the Quad ESL 57 being the granddaddy of the genre in terms of full-range high fidelity reproducers. Over the years there have been many other companies that have become enamoured of the electrostatic principle and have produced ES speakers from the moderately successful to designs that, while revered, nonetheless sank into obscurity.

MartinLogan, however, is the exception, 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 can 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 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-wood-veneered 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 23cm wide by 112cm 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 long-throw driver powered by its own 200W Class-D amplifier, its frequency response 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 ohms, but with the typical dip in the high frequencies — in this case down to 0.8 ohms 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 dimensions makes it a manageable size too.

The Ethos comes with rubber feet for tiled or wooden floors and with beautifully-machined 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 conducted for this review, we 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. Even in a 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!

While we’re on the subject of bass… the Ethos is a bass bully. This is fun and fat bass that rocks. Stick on a percussion or acoustic bass track, such as any on Mino Cinelu’s self-titled CD, and be prepared to be walloped with bass drums that are big, bold and, although not the last word in transient attack, with surprising depth and power. Ditto with the Renaud Garcia-Fons Trio’s Arcoluz CD. Garcia-Fons is a bass maestro who bows, plucks and pulls on strings to create soundscapes that could pass for a number of instruments other than the acoustic bass. The Ethos delivered bass aplenty in a textured and muscular way that had the room shaking. But the bass lagged just a tad in terms of overall speed and definition when compared to that glorious electrostatic panel — albeit to a far lesser extent than in the previous generations we’ve heard. Especially in the lower bass, there was plenty of oomph belying the 37Hz spec (it felt far deeper) but utter detail and resolution was a rung or two below the upper bass, never mind the electrostat.

And yes, that electrostatic panel is a cracker. Put on a vocal track, be it the Waifs’ splendid sisters’ ethereal voices or Chris Jones’ cigarette and whisky-stained tone and the Ethos rewards with a life-like presence that stuns. And not just voices; instruments also sound incredibly real, which we put down to the MartinLogan panels’ utterly accurate timbre, overall balanced tonality and exact resolution. There is a silence between the notes and a lightning-fast reaction to musical signals that starkly define transients and carry musical ebb and flow. And this also translates to an ease and effortlessness that is always enjoyable and never ever brash or bright. The Ethos is smooth and natural to a fault.

Notably, the soundstage the speakers can throw is well outside the speakers laterally, cavernously deep, and with a wide sweet spot, all correlating to the intelligent curvilinear design. Even more surprising, however, is the Ethos’s ability to focus quite competently - if not extraordinarily - images within the large soundstage, a trait that electrostatic designs haven’t been traditionally strong at. Bells, cymbals and all manner of top-end musical content were beautifully rendered.

To varying degrees, some speakers tend to exaggerate the extension of the top octaves to create a slightly artificial sense of ambience and ‘air’; not the Ethos. High frequencies are delicate, fast and utterly natural.

Great looks, advanced engineering, beautiful fabrication by craftspeople in the US, reasonably pricing and musical beguilement — the Ethos shows how MartinLogan’s concerted efforts in introducing novel technologies have paid off in terms of addressing the electrostatic design’s various inherent Achilles’ heels. For starters, the speaker certainly excels at explosive bass crescendos; the ample in-built power and high-quality dynamic drivers (and passive radiators) see to that. The panel is not the equal of the bass section in explosiveness but it is on par with dynamic-design speakers in its price range. Over what felt like an all-too-short stay, the Ethos had us listening to a helluva-lot of music. And that’s what this is all about, right? Enthusiastically endorsed.  

Superb sound & build
Outstanding design
Brilliant build
Bass can be tailored

Low bass not the ultimate in definition

Price: $9495
Quoted frequency response: 34Hz-23,000Hz (±3dB)
Drivers: XStat CLS electrostatic transducer (111.8 × 23.4cm); 203mm (8-inch)
aluminium cone, 203mm polypropylene passive radiator  
Crossover frequency: 375Hz
Power to woofer: 200W (4 ohms)
Quoted sensitivity: 92dB/2.83 volts/meter
Impedance: 4 ohms
Weight: 19kg
Dimensions (hwd): 151cm × 27cm × 46cm
Warranty: 5 years (labour/panels), 3 years (subwoofer driver/electronics)