Think electrostatic hybrid loudspeakers and a handful of names will come to mind, and likely top of that list will be Martin Logan. Here Janine Elliot takes their ElectroMotion ESL X costing £4998 for a spin. 

Many years ago, I decided to delve into a new level of audio exploration, auditioning three sets of top-notch speakers in one of the respected HiFi shops in London. One speaker was made in Sheffield, England, one from Arcugnano, Italy, and the third from Lawrence, Kansas. I bought the former, but also really loved the speakers from Lawrence – that one being a Martin Logan hybrid electrostatic. The reason I didn’t go for the MLs was that I couldn’t sensibly fit them in my then-confined listening area. So, to be offered their ElectroMotion ESL X for review in 2019 I took the opportunity with open arms and a larger living room.

Martin Logan’s location is a bit of a mystery to me. Whilst their website indicates Lawrence, Kansas, they share space with Paradigm and Anthem in Canada, having been also taken over by ShoreView Industries of Minneapolis. Interestingly there was no hint of the place of construction on the speaker itself, though they are distributed in the UK by Absolute Sounds. Build quality has improved significantly since my first dealing with them in that HiFi shop, but that distinctive shape, fast sound, and the large soundstage has remained.

CONSTRUCTION

The ElectroMotion ESL X is one model higher than the entry-level hybrid electrostatic, the ElectroMotion ESL (RRP £3,198 per pair).  The ESL X at £4,998 per pair features a larger XStat panel with a radiating area 50-square-inch larger than the standard model.  One thing of course that distinguishes Martin Logan speakers from the competition is the curvy shape called CLS™ technology (Curvilinear Line Source). As a young audiophile many years ago it amazed me that one could ever create a curved electrostatic construction bearing in mind the exceptionally thin diaphragm needing at all times to be in parallel with the stators supplying the EHT voltage.  This gentle horizontal curvature is not a gimmick but rather it enables excellent high-frequency dispersion from a large radiating surface and without hindering sound quality. Furthermore, it prevents having to have a restricted and overbearing sweet spot, something that conventional flat electrostatic panels can suffer from. It also enabled me to position the speakers easily in my listening area, just ensuring they were toed in by the right amount.

Below the curved and tilting electrostatic diaphragm is the black aluminium bass cabinet, covering a much larger space on the floor than the curved electrostatic membrane itself would. The EM ESL X has dual 8” woofers – one at the front and one at the rear – compared to the base model’s single woofer. These two are housed in a non-resonant and asymmetrical cabinet with a downward firing port. The drivers are custom engineered high-rigidity paper cones, with extended-throw driver assemblies. Much of the design philosophy of the EM-ESL X comes from their more expensive loudspeakers, with custom-wound transformers, air-core coils, large steel laminate inductors, polyester and low DF electrolytic capacitors. The crossover point between the two drivers is set at 400Hz. Custom 5-way bi-wire binding posts allow for good and easy connectability.  In operation, the frequency range was 41–22,000 Hz ±3db. I just wished there were a few more Hz in the bass but connecting my Wilson Benesch Torus sub allowed me to get another two octaves. Martin Logan has a selection of 7 different subwoofers to add, should you so require, or it can be part of a surround system, Martin Logan also manufacturing centre and rear speakers.  Recommended amplifier power is suggested at 20–400 watts per channel, meaning you can use thirsty amplifiers without worry of damaging the diaphragm, unlike the unfortunate time I once had with my aged Quad ELS63’s. Impedance is rated at 6 ohms (1.6 ohms at 20 kHz, which should not be a problem as there is so little power arriving at this frequency, but some amps might not like it); for the purpose of this review the EM-ESL X was lovingly supplied power from my Krell KAV250a. These are fairly large speakers with an overall area of 59.2″ x 9.4″ x 20.7 ” (150.3cm x 23.8cm x 52.6cm), the woofer taking up most of the floor space. The electrostatic section is bolted onto the bass unit at the front and moving the unit into place did mean I needed to be at floor level to get it right; the electrostatic section is not quite secure enough for you to dare risk moving the unit from the top. The unit comes with a choice of spikes or rubber feet, the latter which are inserted over the top of the spikes. Clever. No need to do any screwing in and out. Electrostatic loudspeakers generally require a lot of thinking about positioning at their best, not just the angle of placement and the distance from the wall, but also choosing carefully your seating position. The Martin Logan was surprisingly, and welcomingly, easy for me, and their wide dispersion of sound meant that both I and my cat Claude could listen on the settee without a hint of loss of detail. With a crossover at 400Hz, all the important mid frequencies are covered by the electrostatic transducers meaning an un-distorted frequency response particularly of vocals and upper strings.  This was highly noticeable in my listening tests. The electrostatic panel dimensions are 40″ x 8.6″ (102 x 22cm), with radiating area of 344 in² (2,244 cm²). The transducers themselves employ Martin Logan’s unique XStat™ transducer, developed for the ElectroMotion Series, to reduce the gauge thickness of the electrostatic panel’s steel stators. The reduced thickness also means that the panel has increased visual transparency, so that the unit doesn’t look quite so imposing in the living room, if you want to see what is behind them.

Being electrostatic meant I needed to give the speakers power, on this occasion coming in the form of two 15V DC power units the same size as those coming supplied with your mobile phone. They provide the bias-voltage for the electrostatic panel. For the review I charged the units for 24 hours before listening. There is a status indicator at the rear of the speaker below the speaker binding posts to say they are charging, but I wished the LED was positioned at the front, as being below the speaker terminals make them out of sight unless you are a contortionist. After 30 minutes of no signal the light goes out and the unit goes into standby. When connecting the charger on one occasion the light didn’t show which worried me until I turned on my amplifier and it came back to life. Phew. In standby mode, the power consumption is reduced to 1W; the speaker only taking a second to wake itself up when the music starts. I guess there is a good reason for this apart from saving electricity in that bias voltage can cause the panels to attract dust, which of course isn’t so much of a problem when playing music as they will be vibrating.

SOUND QUALITY

Sometimes initial reactions can be different to long listening sessions. My initial reaction after setting up the speakers was “wow”; suddenly the orchestra came away from the loudspeakers and I was amongst the musicians. The sound was very real and tireless. If I wanted to have a long listening session I wouldn’t get exhausted.  At the time of first auditioning ML back in the last century I was very much into Genesis, so I decided it would be very appropriate to start this audition off with ‘Nursery Cryme’, an album released in 1971 though it didn’t actually get into the home UK charts until 1974. It comes in as one of my favourite albums from the group, the first to feature drummer/vocalist Phil Collins.  The group did some amazing music, but I felt the studio engineering was less than perfect; often with a mid-frequency prevalence and uninspiring soundstage. A good test for the Martin Logan’s then. Having set up the soundstage ideally for my listening test I could now begin to evaluate the speakers. Where conventional speakers can be hard to position perfectly and often have many idiosyncrasies such as resonances from the drivers or the box, the electrostatic panel is much freer from these. Listening to the album it was just as bad as I remembered it. What I did notice though, was how good vocals came into the room, with details from each instrument in their own defined area, not just left and right, but also front and back. Only that the bass end was slightly too prominent for me and slightly ‘separate’ from the electrostatic section, though both observations seemed to improve the more I listened. Having the mid-high frequencies emanating from such a large area made listening highly engrossing. Turning to Patricia Barber ‘Live in France’ and the track “Gotcha” I could start to experience and adore the tight initial transients from the close-mic’d percussion. It also gave me a chance to take in the depth of the soundstage as well as from left-to-right. The electrostatic diaphragm is so lightweight, that the tight cymbal sounds were as close as you can get to reality. The second track opens with piano solo, and the ML’s give you a chance to explore and get close to the instrument just as pianist Patricia was herself. The performance was unhurried, though still very detailed. I was listening to the live recital, not my HiFi. Only the live audience applause seemed less real than I was used to; quieter and too polite. I was concerned that there would be spill between both diaphragms causing issues, but Martin Logan have thought of everything; whilst the ElectroMotion-ESL X radiates sound with equal intensity from the front and back of its diaphragm the outputs are of course in opposite phase. As a result, sound waves rippling out toward the sides meet at the loudspeaker’s edge and cancel. This allowed for an accurate stereo definition though at the same time giving bigger areas for sitting in order to enjoy the music; ideal if there are more than one of you in the house. Just make sure you don’t place the units close to a side wall. The sound emanating from the rear was out of phase with the front though added depth to the sound, especially the closer it was to the wall. Luckily, the size of the woofer cabinet does limit you getting too close. I did feel the need to damp the sound behind the unit to control some of the rear reflection. Sound in front had a wider sound stage than that at/behind the speaker, so minimising it with curtains was a good ploy. Having the electrostatic element angled up means vibrations from the floor can be minimised.

Turning to Mike Valentine’s compelling album “Big Band Spectacular”, this time the version on reel to reel tape, it gave me a chance to hear the orchestra playing in my very own living room. I attended the original recording live at Air Studios so remember the live acoustics. I also love this album as it relives memories of my parents playing Glen Miller albums at Christmas time from their mono valve PYE radiogram. Whilst everything was being played well, there was a slight hint of accentuated mid frequencies overpowering detail of the higher percussion cymbals and brass harmonics. As a sound-engineer I did want to hear a piping-hot rendition of this energetic album at the higher frequencies, particularly the closing track “Anvil Chorus”, but rather than hot chilli peppers I got more of a well-made Sunday roast. Don’t think I was complaining about the speakers; I loved them, and Sunday roast, just that everything was very polite, like spending Sunday lunch with my mum. Whilst musicians weren’t so easy to pinpoint at the listening position on my settee as with my own speakers, the result was a welcoming delicacy with the detail, with the sound covering a large space in front and behind the speakers that made listening equally enjoyable for me and my cat who was often sitting on the next seat. If you want an analytical and punchy sound these are not for you; these speakers are natural and lush sounding meaning I could relax and enjoy the musicians for long listening periods. That 400Hz crossover helped considerably to keep things natural, giving a noticeably good presentation of vocals and string music. I did, however, notice on a few occasions some “change” between the drivers at frequencies covered by instruments such as the cello and viola. However, a full-range electrostatic can mean a loss in the bass end, and ML’s experience with subs and bass drivers showed off well in the ESL X; the bass/electrostatic hybrid generally working well in practice. What really made these speakers pleasurable was their ability to play any kind of music with equal care and honesty. If you want anger and spite look elsewhere. On a few occasions I did find the bottom end could be slightly overpowering, so please Martin Logan add a volume control as is featured in some of your more expensive speakers. However, for a few pounds short of five thousand this loudspeaker presented a very special time for me when set up in my audio space. I constantly felt the musicians were in my house, whether playing pop or classical, orchestral or electronic. Not many speakers can own up to this.

The depth of soundstage and detail was so good. It also got me into deciding to play the highly engrossing album ‘Memoryhouse’ from Max Richter. This is an album that begins with the track “Europe, after the Rain” starting and finishing appropriately with the sound of rainfall, and which is an emotional montage of 1908 music on the radio, spoken vocals, close miked violin and restrained piano playing in the distance. The positioning was just right.  The track is full of repeated pulsing effortless chordal phrases. This use of gently pulsating simple repeated ideas in all the tracks on this album is highly addictive. Indeed, the basic repeated theme of track 1 is heard again in some form in all 18 tracks! Only in track six (“Untitled/figures”) is there a hint of excitement, a track with beats and a celesta adding to the violin solo. The ML loudspeakers showed just how fast transients and details are on electrostatics, and the angled diaphragms meant that the sound was in the room, not in my face. Detail of space was still large and highly addictive, despite the repetitiveness of the music. Bass was fast and having both front and rear 8” drivers enabled the sounds to fill the room completely. The speakers gave me an opportunity to forget that they were actually there, and having such a large vertical sound field from the electrostatic tower block created a large vertical soundstage just as in the concert hall.

My only criticisms at this price were small; that rear-facing LED and the fact that I wished there was a volume control for the bass at the rear, as is fitted in some of the more expensive speakers in their Expression range. There was a tendency for the bass end to overstate, so positioning greater than a foot away from the back wall was essential. My early experience with ML’s left me with the feeling of a weakness in the bass, and the ESL X shows that Martin Logan has come a long way since my first listening in that London HiFi shop.

CONCLUSION

That initial “wow” factor was there for most of my review. It was so good to audition a speaker that seemed to work with all kinds of music. The speaker eked neutrality and musicality with an excellent sound-stage, just that the bass hid some of the greatness from the electrostatic inducers. The ElectroMotion ESL X was particularly good on vocals bringing them out better than on many a speaker I have listened to, whatever the price. Only on a few tracks did I find a slight sibilance. Be careful to match it carefully with your amplifier, so listening to it before you buy is well worth doing.

AT A GLANCE

Build Quality: Well put together with good connectors. Be careful moving them around.

Sound Quality: Fatigue free listening, with an almost holographic staging of the music, plus the speed of mids/highs that only electrostatics can muster.

Value for Money: £4998 is very good value for a hybrid electrostatic of this calibre.

 Pros:

Delicacy of sound

Work equally well on all types of music

Efficiency

Ease of placement

Cons:

Bass can sound detached from the mid/highs

Some might not like the impracticability of running power leads to both speakers

Price: £4998

Janine Elliot

Review Equipment:

Ferrograph Logic 7 and Revox B77 reel-to-reel, Krell KPS20i CD, Pre-Audio turntable/AT33sa cartridge/Manley Steelhead phono, PC FLAC/DSD files, Krell KAV250a amplifier

SPECIFICATIONS

Specifications are subject to change without notice