MartinLogan ElectroMotion ESL X Review
The description “transparent sound” has never fit a speaker in this class better.
LASSE SVENDSEN
A unique speaker like the Martin Logan Electromotion ESL X can do something many others cannot. If you can live with a few compromises, you get sound quality with some magnificent qualities.
When everything is as successful as here, you get both powerful bass and crystal-clear sound, but it requires some unconventional solutions.
This unusual speaker design fits into the long line of hybrid speakers from Martin Logan. They have been building speakers with two completely different technical solutions for a long time and have almost perfected the combination of conventional bass drivers and electrostatic elements – known as XStat.
This is a more expensive and complicated solution than the traditional one, which involves combining a dynamic bass driver with a voice coil, magnet, and cone-shaped membrane with a small dome-shaped tweeter – all in one box.
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The marriage between ordinary bass drivers and a transparent electrostatic membrane combines the best of both worlds, creating a dynamic, focused, and open sound rarely found in this price range.
The transparent membrane is a conductive film so light that it must be stretched on a vertical, curved frame so it doesn’t blow away when the current sets it in motion.
In the cabinet, where the frame is screwed in, there are two powerful 20 cm bass drivers – one on the front and one on the back – the bass cabinet acts as the speaker’s subwoofer. It covers the frequency range from 41 to 400 Hz. The rest of the music comes from the 101.6 cm long and 21.8 cm wide XStat electrostatic membrane.
The challenge is to get the four bass drivers to react as quickly as the transparent electrostatic. Since the thin film has much less mass than the bass membrane – which also carries a voice coil – Martin Logan has worked long to develop an effective crossover with polyester film capacitors and steel-laminated inductors.
JUST ONE CROSSOVER
The two bass drivers are mounted back-to-back in a bass-reflex cabinet with the port at the bottom and cross over as low as the electrostatic element allows. The rear driver is tuned to play from 100 Hz and below, and the front one crosses at 400 Hz.
A larger electrostatic membrane, like in the Martin Logan Impression ESL 11A, has a larger bandwidth due to its larger surface area, so in the ESL 11A, the crossover frequency can be lowered to 300 Hz.
The ESL 11A has active basses (built-in bass amplifier) and room correction, but the ESL X is a passive speaker. The electrostatic membrane needs power, which it gets from two small 15V transformers; otherwise, the connections are quite conventional, with solid cable terminals for bi-wiring/bi-amping.
ALTERNATIVES
There aren’t many similar speakers in this class. The slightly smaller and 20,000 kronor cheaper Electromotion ESL (without X) is the only alternative among hybrid speakers. Among conventional speakers, perhaps the retro-cool JBL L100 Classic is an alternative. The highly successful KEF R11 is another, and Sonus faber’s Sonetto series is a third.
They all have their given qualities, but none of them have the super-neutral midrange and lightning-fast transient response of Martin Logan speakers.
PLACEMENT
The ESL X is 150 cm tall, 24 cm wide, and the bass cabinet extends 53 cm backward, but they can be placed near the back wall. The transparent electrostatic membrane is a design bonus because you can see the back wall through the speakers. Thus, the speakers don’t seem as dominating in the room.
Since the electrostatic is open on both the front and back, sound waves also radiate backward. To make the timing as optimal as possible, it is important that the distance from the speakers to the back wall is the same for the right and left speakers.
Under the bass cabinet are rubber feet, where the rubber top can be removed if you prefer to use spikes for better stability on a carpet.
Martin Logan’s user manuals are among the best available; they clearly explain why they recommend angling the speakers toward the center of the sofa. This provides the best sound balance and avoids unwanted reflections from side walls.
DEVIALET CONFIGURATOR
Our test pair played with various amplifiers, from the new Hegel H120 to Rotel’s new high-end amplifier combination in the Michi series. They were also tested with the Devialet Expert 220 Pro, which has speaker-adapted digital processing. This corrects the timing in frequency between the right and left speakers, protects the bass drivers’ voice coils from overload and corrects the bass response.
Devialet calls this technology SAM, and while the speakers sound great with all good amplifiers, an Expert Pro with SAM tightens the focus slightly and gives the bass a bit more reach.
Regardless of which amplifier you prefer, it’s worth considering that the speakers’ impedance of 6 ohms is not constant. It changes with frequency and drops to 1.6 ohms at 20 kHz. This can cause problems for some tube amplifiers and weak amplifiers with moderate damping factor.
LIGHTNING-FAST DYNAMICS
After careful placement in the test room and a few days of break-in, it was time for another deep dive into the hybrid speaker’s qualities.
But let’s start with the shortcomings.
The ESL X has noticeably stronger and more dynamic bass reproduction than the Electromotion ESL, and although it plays a little louder, it does not reach the same volume as a pair of KEF R11 or Audiovector R3 Arreté. If you like heavy bass and loud music, this is hardly the speaker to choose.
The electrostat has only 30 degrees of horizontal dispersion of sound waves, so they must be angled inward to place the treble correctly in the soundstage. But this also means that the optimal listening position is somewhat limited. Two or three people can sit next to each other and listen, but only the person in the middle will get the sound balance perfectly reproduced.
When everything aligns – the amplifier, the placement, the music – and you are ready for musical entertainment, there are few speakers that can match the crystal-clear sound of an electrostat.
In Khalid’s “Better,” you can feel the bass clearly in your gut, and the voice is perfectly focused in the middle of the soundstage. Switching to Mirella Freni’s soprano in Puccini’s “La Bohème,” you immediately notice how fantastically uncolored the sound is. The singing voice is so sharp that it could be used as a knife, but it is never unpleasant.
The speaker’s treble response can very well be said to be relaxed in the highest octaves, which may be the reason you rarely feel discomfort when playing opera as loudly as it should be played.
It is almost impossible to find any distortion at normal listening volume. Keith Jarrett’s trio in “Inside Out,” or Pat Metheny’s live recording of “Are You Going With Me,” is crystal clear and pure. The combined four bass drivers play tight and powerful, and the electrostat’s open and transparent reproduction gives the piano sound plenty of nuances and details.
The more expensive R3 Arreté is even more resolved and detailed, but not quite as neutral in the midrange. The perspective is rock solid, and the soundstage is convincingly deep, and the ability to create the sought-after holography in the room between the speakers and the listener is outstanding and something often only experienced with a successful electrostatic design.
Specs
Type: Two-way electrostatic hybrid
Bass: 2 x 20 cm
Midrange/Tweeter: 102 x 22 cm electrostat
Power Handling: 400 W
Input: Dual pairs
Sensitivity/Impedance: 91 dB/6 ohms
Frequency Range: 41–22,000 Hz (±3 dB)
Dimensions/Weight: 150.3 x 23.8 x 52.6 cm / 23.6 kg
Color: Black lacquer
Verdict
Martin Logan’s Electromotion ESL X perhaps has the most natural and uncolored midrange of any speaker in this class. It also has lightning-fast dynamics and extremely generous bass reproduction. Other speakers play louder, but few play as crystal-clear, clean, and focused – and when paired with a really good amplifier, everything is set for musical experiences that conventional speakers have difficulty matching.
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