- Manufacturer & Model
- MartinLogan Expression 13A
Low distortion, great imaging, effortless delivery at high output levels, with optional Anthem Room Correction (ARC) via the Perfect Bass Kit (PBK).
The MartinLogan Expression 13A electrostatic speakers are a great choice for 2-channel and home cinema environments. They present a huge sound stage and superb detail that is rarely matched.
MartinLogan Electrostatic Magic
by Wayne Myers
Each time I walk into Cedar Creek Cinema (CCC) at the beginning of an AV get-together weekend, there is something different about it. For my last visit, it was the stately pair of MartinLogan Expression ESL 13A electrostatic speakers. This review will be about the 13A speakers and the journey to properly introduce them into the Cedar Creek Cinema sonic environment.
Robert Pirsig, in Zen and the Art of Motorcycle Maintenance, said that a work of art is complete when the artist and his materials both come to rest relative to each other. I always liked that way of thinking about the creation process, but never thought about it in the context of speaker setup and room treatment until working with the Expression 13A. After several days of planning, implementing, listening, measuring, adjusting, listening some more, then incrementally refining and finally hearing a result that was both exhilarating and relaxing at the same time, I realized that Pirsig's description also fits the work of speaker and room configuration and calibration. Does that make us artists? Perhaps, after a fashion, when you consider the peaceful exhilaration we are used to and insist upon and pursue to its final attainment.
There are so many excellent speaker choices available to the listener these days that a review like this becomes less about whether a speaker is good vs. not-so-good and more about where a given speaker might work best and how to get it to do so. In this case, the Expression 13A, with proper subwoofer support, must deliver STRONG bass, reach high volumes, ultra-low electrostatic distortion, be EQually comfortable handling cinema and two-channel tracks, and provide pinpoint imaging with the huge 3-dimensional soundstage that we have grown accustomed to in this room. That's all!
Expression 13A Premium Electrostatic Loudspeaker
The speakers being reviewed are the MartinLogan Expression ESL 13A hybrid electrostatic loudspeakers. The Expressions 13A are priced at $14,995 retail point on the lineup for MartinLogan, featuring their new 13-inch panel and dual 10-inch powered woofers, each with its own amplification and DSP.
The 24-bit DSP built into the Expression 13A serves two purposes. Anthem Room Correction (ARC) helps smooth out the LF interaction with your room, for one. In fine-tuning of the integration of ESL panel and LF drivers, an area of expertise in which the ML engineering team already excels, the DSP also affords the 13A its +/- 10 dB bass (below 75 Hz) and +/- 2 dB mid-bass controls for user tuning of those ranges.
The new, larger panel design used for the Expression 13A is a plus for those who want high output and low distortion. I have found the newer panel designs to provide improved off-axis performance, an important quality for the SS&I (sound stage & imaging) hounds who use off-axis listening angles to fine-tune the SS&I experience and hope for minimum HF response degradation in the process. Stronger frames around the panels add rigidity and strength to the panels. Cabinet work is always first-rate, but that is a minimum-level expectation that most reputable speaker manufacturers know they must meet. Sonnie’s 13A pair came in a Walnut finish, one of the four standard finish options. Gloss Black, Gloss White, and Dark Cherry are the other three. Seven additional +premium finishes are also available.
Custom binding posts and custom feet with spikes built in come on each Expression 13A.
Setup and Configuration
Our main priorities were (1) strong bass and (2) room correction for all channels for the best SS&I possible. We thought this could be accomplished by running Dirac Live for 2-channel and Audyssey XT-32 for surround, since the Denon AVR could provide 11 channels of correction and the DDRC-88M was limited to 8 channels. But we were foiled by some HDMI limitation between the OPPO player and the Denon AVR, and could not get a navigation display on our cinema screen for 2-channel listening when switching to the DDRC-88BM. This was the case with both Direct and Pure Direct mode in the AVR.
With the Dirac Live unit moved downstream of the Denon AVR, and the use of L/R Mains Passthrough mode in the Denon AVR, we found the best of all worlds. Bass enhancement in the neighborhood of 15 dB at 20 Hz and smooth, tight bass was accomplished through a combination of distance adjustments, and Dirac and Audyssey room correction, along with custom parametric filtering below 300 Hertz. Dirac Live also gave us impulse response correction for higher frequencies and Audyssey provided the bass boost desired for all channels. Along the way, we passed through multiple setup refinements before finally ending up at this desired configuration.
Are you feeling a little lost? So did we, many a time. In the end, the frequency ranges of the system L/R Mains signals were handled as follows:
- LF up to 60 Hz - SVS PB16 Ultra subwoofers with internal PEQ plus Audyssey XT-32
- 60 Hz to 80 Hz transition between subwoofers and Expression 13A - PEQ filters in DDRC-88BM, affecting only the 13A signal, to correct a couple of minor frequency response errors in the transition range affected by them both; also, the subwoofer distance settings in the AVR were tweaked to help smooth this transition range
- 60 Hz to 300 Hz - Expression 13A woofers with ARC plus Dirac Live correction and custom target curve
- 300 Hz to 20 kHz - Expression 13A electrostatic panels with Dirac LIve correction and custom target curve
Upon my arrival, I found the 13A set up with the PBK ARC correction calibrated and active in the 13A and with Audyssey XT-32 calibrated and active in the Denon AVR. Initial listening tests were very pleasing, featuring a crisp, clean sound typical of electrostatics. The imaging was very good but not as sharp as I knew it could be. An impromptu shift forward in the listen seat showed that a slight outward shift in the 13A toe angle would improve it. But the placement symmetry was so good already that we elected to allow the soon-to-be-implemented Dirac Live room correction to do the fine finishing work on the SS&I, and it did.
This is a strategic decision every user faces. In my own systems I tend to go overboard getting the physical speaker position and raw SS&I as near perfect as possible, putting minimum burden on the room correction tool, generally Dirac Live in my systems. But most will prefer the speedier and less tedious approach of getting SS&I into the “good” to “very good” range and letting Dirac Live do the rest - with top-drawer results. It boils down to a matter of personal preference and one’s obedience to his own obsessive drives.
I noticed right away that the bass was just a little flabby or not well-controlled. Turning off Audyssey tightened the bass significantly. This loose-bass effect remained a potential issue when we were pushing full-range bass to the woofers of the 13A with room correction and with no subwoofers running, even with the 13A ARC active. With the DSP and internal amplification and ARC feature, it was not obvious why this would be so. But since we were headed toward always having subwoofers active for all types of program material, cutting off subwoofer frequencies to the 13A removed that nuisance effect, so we did not spend much time chasing the mystery.
The Expression 13A with ARC calibration active in the woofer frequency range up to 300 Hz did a very satisfactory job of keeping the bass tight and accurate. Typical room mode effects appeared with the ARC turned off, a situation we put up with for only a few tracks. The symmetrical woofer arrangement gives the benefit of potentially reducing that effect in some situations, along with thoughtful physical placement of the speakers themselves in the room. Sonnie was way ahead in that category, the physical placement was impeccably symmetrical in the exact spot where many other speaker models had given their best in this room. The accuracy of the uncorrected SS&I told us, “Leave that placement alone” in our system config experiments.
Believers that little should be left to chance concerning the rear wave from an electrostatic panel, we were already dealing with reflective panels behind the 13A at the front wall, intending to take control of the direction from which the rear wave arrives at the LP relative to the 13A front wave, and additionally helping match the timing of those reflected waves. Some minor adjustments in their placement contributed to a delivery that had impact and energy and gave heightened sense of depth acuity to the imaging. My own approach to treatment of the front of the room, especially with dipoles, gets a little involved and will be documented elsewhere. Improvement in image clarity, detail, and impact are the big payoffs.
We put to use the well-known technique of pre-EQing low frequencies in systems that will use room correction so that Audyssey or Dirac Live will have an “easier job” working at those crucial, and sometimes challenging, room mode frequencies. We had the ARC in the 13A and several bands of Parametric EQ available in the dual PB16 Ultra subwoofers, which were also placed in well-proven locations in the room. With pre-EQ applied in the 13A and the subwoofers, we got exceptionally clean and flat, well-controlled bass with no flabbiness.
With pre-EQ applied to the 13A with ARC and PEQ in the PB16 Ultra subs, and Audyssey XT-32 calibration active in the Denon AVR and the subwoofer crossover in the AVR at 60 Hz, we then found that switching the AVR to L/R Mains Passthrough mode would deactivate Audyssey processing to the 13A and allow us to run Dirac Live to correct them. Crossover and timing adjustments plus a few additional PEQ sections were included in fine-tuning efforts as shown below.
If that sounds a little complicated to follow, it was. Several times we had to redo pieces of the calibration process because we realized a step had been skipped or done in the wrong order or we had misunderstood how a mode change would affect a crucial setting.
The final result of all of this was simply superb. Many of the little tweaks toward the end of our process were to flatten response bumps and dips that were bothersome more to our analytical left brains and would probably never be heard. But we do it anyway, because we can and must!
It is also important to note that at many points in our evaluation process we focused on the sound of the Expression 13A "native," with ARC active and no other correction or EQ in place. Many listeners will choose a straightforward setup such as this in their rooms. The effortless neutrality of delivery from the electrostatic panels is a quality that one must witness to appreciate. It is a combination of smooth, extended frequency response with low distortion that makes that delivery possible. The addition of ARC for the woofers to help conquer room modes is a huge plus and will be all the equalization that many will dream of needing.
On top of all of this, the Expression 13A can dish out all the bass that many listeners will be looking for. Sonnie likes an extra measure of low bass that calls for subwoofer support, but the dual-woofer design, with 300 Watts of continuous power per, will crank out bass down to the low 20 Hz range with ease.
A final note on distortion. Through the frequency range of the panels, the measured distortion of all harmonics remains consistently low, all grouped together, and smooth, with nothing to stand out and annoy, if one can think of the distortion curve for a single harmonic as smooth. These details, easily overlooked, all add up to a sound that is less than the sum of its parts, that sum adding up to the effortlessness of sound we are referring to.
Their ability to image can blow minds, although a dipole speaker can take a bit of positional tweaking to get to that point of imaging magic. I have heard electrostatics that were set up at trade shows that left listeners wondering what all the hoopla was about. But persistence pays off, and we heard electrostatic magic galore in our sessions, with and without the extra room correction referred to.
“Ain’t It A Shame” - B-52's - One of a few favorite test tracks that I have heard hundreds of times, and I have learned to listen for certain detailed characteristics in the SS&I. The vocal echoes are especially telltale. When the L and R reflected wave is carefully timed so their delays match, those echoes coalesce and sharpen in the upper right corner of the ss with a sharp outline and clarity that pulls it forward from vagueness to stark sharp image in its own right. What was once barely noticed now insists on the listener’s attention. This effect is heightened with Dirac Live to the point of “messing with your head,” but with enough care in setup, the 13A are more than capable of getting you close on their own. In fact, I was surprised at how close to “corrected” the 13A could sound without correction applied. The difference with A-B switching was easy to hear, mainly due to high frequency rolloff. But to walk into the room and listen without knowing it, one might very well not be able to tell that Dirac was turned off.
“Vision Of A Kiss” - B-52's - The strummed octaves from the guitar on the left is almost made delicate by the simple clarity of their tone, the hand claps on the chorus almost seem to slap you. The impact that is experienced by the careful attention to the impulse response alignment is impressive on this track. The strummed acoustic guitar in center, between verses, is simple but punchy.
Comparing between EQ on and off, with PBK active and just re-calibrated, the frequency response is only slightly raw sounding, the voicing of the Expression is very natural, a little peaky in the midrange, neutral but lively due to the slight voicing accent in the upper-mids.
“Perfect World” - Broken Bells - The uncorrected 13A do not completely disappear in soundstage, but only a slight move forward in the listening chair, about 1.5 feet, puts ones head in a position where this does occur. The kick drum is tight with a nice punch. Cymbals and hi-hat are extra clear. In a setup without correction, this speaker “disappearing act” would be accomplished with further slight re-positioning, and there is no doubt it can occur with the 13A, as I have heard it with every other uncorrected MartinLogan hybrid electrostatic model I have worked with. Our choice was to allow the polishing of Dirac Live to accomplish it.
“I Love You” - Climax Blues Band - Cymbal Clarity, WOW, beautifully recorded and wonderfully presented. The snare punch and clarity of the string section that back this track are almost like living a dream. Are they singing about a girl or these speakers?
“Don’t Panic” - Coldplay - This is a song with strongly mixed bass guitar, a good test for bass smoothness and for how well the bass blends with the rest of the mix. The Expressions handle it without the slightest weakness or thinness, and without overwhelming the upper ranges of the mix, strong and integrated. Oneness.
“We Are One” - Buckethead and Friends - Where “Don’t Panic” shines with deep bass, “We Are One” sizzles with almost too much treble. The low-distortion output from the 13A electrostatic panels makes you want to sit and take it. The ringing floor tom in the silent spaces of this mix reminds you that these speakers are made to fill a big room with full-range sound at dangerous levels with ease. What a way to lose our hearing. Don’t Do This At Home, though - protect your hearing with your life. You will want to be able to enjoy these speakers for many years.
"One Voice" - Wailin' Jennys - The 13A can be as laid back and subtle as they need to be, and this track showed us terrific separation between vocal images and a beautiful resonance of the acoustic guitar just after the song's midpoint that threatens to stop my heart almost every time I hear it on the right speakers. And the Expression 13A are the right speakers for that sound.
"Late In The Evening" - Paul Simon - The horns, that belt, the percussion, Paul’s vocals, music to love about music to love and laid out by speakers to love made by people who love music. There comes a point where the 13A start to blend with the room and music to the point where you forget to pay attention. They become forgettable. That is a good quality in a speaker, and not easy to come by.
Playing loud, VERY loud, without beginning to display little flaws of character, is a talent the 13A and their siblings in the MartinLogan ESL family. Dome tweeters, horns, most other high frequency transducers on the market within reach of the wallets of mortals - plasma tweeters are special specimens with special price tags - will have their way of letting you know when they are reaching their limits of transparent reproduction. The electrostatic panels of the Expression 13A appear to have no such limit in the practical SPL listening range, at least that I could ever detect. Uncorrected frequency response is smooth enough, even off-axis, that there are no peaks that become annoying at higher levels, although the slight upper-mid emphasis might lead to fatigue for some listeners over an extended time. With the polish of Dirac LIve correction, that voicing emphasis is tamed to where speakers disappear and only music remains.
“Knocking On Heaven’s Door” - Warren Zevon - There is a slight hollowness in the uncorrected sound, which is eradicated by the Dirac Live correction. Vocals and guitars all sing with a resonance that says they are true to life, yet remain integral to a punchy and heartfelt performance and mix.
We watched the following movies beginning to end:
- Mechanic Resurrection
- The Fifth Element
- Jason Bourne
- 13 Hours
- Pacific Rim
With bass to the 13A cut off at 60 Hz, the woofers were not working at full throttle like they might be asked to in some systems. At higher volumes, this will ease the burden placed on the dual 10-inch powered woofers, helping them deliver their frequency range - up to 300 Hz - with lowest possible distortion. This point will matter for home cinema, especially action-oriented films with more going on in the LFE channel, and in music tracks where distortion is likely to be more noticeable.
Only one minor annoyance became evident during our cinema sessions. The rear grille on the Expression 13A is perforated steel, and lies against a felt pad to keep it from rattling. But our 13A were adjacent to the fronts of the SVS subs and at a certain frequency, that rear grille did rattle. We ended up removing both rear grilles to stop tet rattling. The ML engineers will certainly solve this with a tighter fastening system and/or improved padding.
I especially enjoy the audio on movies where audio effects and music and action sounds are difficult to tell apart, as with Eric Serra’s soundtrack for The Fifth Element. Another good example of that kind of soundtrack is Blade Runner by Vangelis, a great soundtrack but from a point in time well before soundtracks tended to get bass-heavy and speaker-stressful. Subtle details simply pop out of the soundstage with the 13A. Anything less than the SS&I quality we insisted upon would have much of that detail buried in the extraneous sonic fog.
The MartinLogan Expression 13A are the kind of speakers you can easily forget. That is a high compliment for a speaker review. Once in place and supported by proper room treatment, and perhaps a little room correction for ultimate smoothness and ideal SS&I - don't forget about the optional ARC correction built in - I predict most listeners will quickly become comfortable with the inability to find the 13A in the room - they can disappear that completely - and become completely sonically unobtrusive in their systems. The Expression 13A are another example of Electrostatic Magic from the Electrostatic Wizards at MartinLogan. I highly recommend them.
Associated Review Equipment
- Panasonic PT-AE8000 Projector
- Denon AVRX4300H AVR (amplification for surround and height speakers)
- miniDSP DDRC-88BM 8-Channel Dirac Live Processor with Bass Management
- Parasound A31 3-Channel Power Amp (LCR Speakers)
- MartinLogan Expression ESL 13A x2 (L&R Main Speakers)
- MartinLogan Stage X (center)
- MartinLogan Electromotion ESL x2 (rear surround)
- MartinLogan Motion AFX ATMOS height x4
- SVS PB16-Ultra 1500 W 16-inch Ported Subwoofer x2
- Frequency Response: 24–23,000 Hz ±3dB
- Horizontal Dispersion: 30°
- Vertical Dispersion: 44" (112cm) line source
- Panel Dimensions: 44" × 13" (112 × 33cm), 572 sq in, 3,696 sq cm
- LF Transducer: Two 10” (25.4 cm) cast basket, high excursion, rigid aluminium cone and extended throw drive assembly, non-resonance asymmetrical chamber format.
- Room Correction (LF): Anthem Room Correction (ARC) ready, sold separately
- Amplifiers (LF): 2 x 300 W/channel continuous (4 ohms), 2 x 600 watts/channel peak
- Recommended Power: 20 to 600 W per channel
- Sensitivity: 91 dB/2.83 v/m
- Impedance: 4 Ohms, 0.7 at 20kHz. Compatible with 4, 6, or 8 Ohm-rated amplifiers.
- Crossover: 300 Hz
- Bass: ±10 dB under 75 Hz
- Mid-Bass: –2 dB, 0 db, +2 db
- Light: On, Dim, Off
- ARC™ Room EQ: On, Off
- Power Draw:
- Idle:< 1W/channel
- Max: 500W/channel
- Weight: 103 lbs. (46.8 kg)
- 61.5" × 13.4" × 27.5"
- (156.1cm × 33.9cm × 69.9cm)
Frequency response at 0.5m on axis, with 3ms IR window to reduce the influence of reflections, at 30in ref height on the electrostatic panel above the floor (blue trace), the panel height at which sound radiates perpendicular from the panel to ear height at the LP, 0.25m higher (green), 0.25 m higher again (red), and 0.25m lower than ref height (plum), 48th oct smoothing. These plots show the consistency of frequency response up and down the panel, especially through the upper midrange from 2 kHz to 10 kHz.
Frequency response at 1m on axis with 4ms IR window to reduce the influence of reflections (tan), and off-axis at 11 degrees (violet), 22.5 degrees (plum), 34 degrees (blue), 48th oct smoothing.
Frequency response at 1m on axis with 4ms IR window to reduce the influence of reflections (tan), and off-axis at the 14 degree LP listening angle, 48th oct smoothing.
Woofer frequency response, front woofer 0.5m on axis (green), front woofer 1m with mic on-axis but on the floor (blue), front woofer 0.1m on-axis (plum), back woofer 0.1m on-axis (dark green).
Frequency response at the Listening Position from the left (green) and right (plum) speaker, 6th oct smoothing.
Frequency response with ARC active on the Expression 13A, at the Listening Position from the left (dark green) and right (blue) speaker, 6th oct smoothing. Notice how effectively the range below 300 Hz is controlled.
Frequency response with ARC active on the Expression 13A plus Dirac Live calibration, at the Listening Position from from the left (tan) and right (green) speaker, 6th oct smoothing.
Frequency response with built-in parametric EQ in subwoofers, Audyssey XT-32 for subwoofers, and additional parametric EQ in the DDRC-88BM to blend the subwoofer / Expression 13A at crossover.
Impulse response diagram shows the front wave and rear wave impulses and how their timing is carefully matched at the LP.
Matching of the impulse timing for the front wave shows a perfect overlay, indicating a perfect match of the delay times at the LP.
Matching of the impulse timing for the rear wave shows a near-perfect overlay, indicating a very good match of the delay times at the LP. This will greatly enhance the SS&I performance.
Several views of Cedar Creek Cinema front of house, including the MartinLogan Expression 13A and MartinLogan Stage X center.
Cedar Creek Cinema seating rear wall treatment / wall mounted media storage, MartinLogan Electromotion ESL surround speakers. sonically absorptive covers on front three seat backs, and little green guard/mascot (NOT Sonnie Parker.).
SVS PB16-Ultra Subwoofer
MartinLogan Expression 13A.
Reflective Panel.behind the Expression 13A for controlling the rear wave reflection direction, timing, and strength at the LP.
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