Surround Sound Speaker Systems

MartinLogan 5.1 Home Theater Speaker System

ARTICLE INDEX


Introduction

I remember the first time I saw a pair of MartinLogan electrostatic speakers. It was 1993 and I was still in high-school, shopping for a new car stereo. And then I saw them, a pair of tall ominous black panels. I was immediately intrigued by the strange looking panel. Asking for a demonstration, I was politely refused, who would think a teenager with a scratched rap CD fresh off the car audio demo system could afford (or even appreciate) such a speaker?

It is now 16 years later and I have four MartinLogan products in my listening room and my musical tastes have changed considerably. Gone is the bass-thumping rap of my frivolous teenage days, now I lean towards harder heavy rock, with some world music and acoustic guitar thrown in for balance. Still like the bass though.

Lets' face it, Electrostatic, or for that matter all panel speakers, are hard to forget. Unlike the monkey-coffin shape of most box speakers, panels just ooze class. And the sound, it is as polarizing as their appearance. You either love 'em or hate 'em. And the reason the response is divided is partially because electrostatics require careful room and equipment choices. It was this that concerned me. Would my room be able to accommodate? Will my electronics do them justice?

Specifications

  • Summit X Front Main Speakers
  • Design: ESL Hybrid
  • Horizontal Dispersion: 300
  • ESL Panel: 44" Line Source
  • Woofer Driver: Two 10"
  • Built-in Woofer Amplifier: 200 Watts RMS
  • MFR: 24 Hz - 23 kHz ± 3dB
  • Sensitivity: 91 dB/2.83 Volts/Meter
  • Impedance: 4 Ohms, Minimum 0.8 Ohms
  • Crossover Frequency: 270 Hz
  • Bass Control: ±10 dB at 25 Hz and 50 Hz
  • Power Handling: 300 Watts
  • Dimensions: 60.9" H x 12.7" W x 3" D
  • Weight: 75 Pounds/each
  • Price: $13,995/pair USA
  • Vista Rear Surround Speakers
  • Design: ESL Hybrid
  • Horizontal Dispersion: 300
  • ESL Panel: 40" Line Source
  • Woofer Driver: One 8"
  • MFR: 43 Hz - 30 kHz ± 3 dB
  • Sensitivity: 90 dB/2.83 Volts/Meter
  • Impedance: 4 Ohms, Minimum 1.2 Ohms
  • Crossover Frequency: 450 Hz
  • Power Handling: 200 Watts
  • Dimensions: 57" H x 10.7" W x 16.8" D
  • Weight: 54 Pounds/each
  • MSRP: $4295/pair USA
  • Stage Center Channel Speaker
  • Design: ESL Hybrid
  • Drivers: One 1" Soft Dome Tweeter, Electrostatic Midrange, Two 6.5" Woofers
  • MFR: 69 Hz - 22 kHz ± 3 dB
  • Horizontal Dispersion: 300
  • Sensitivity: 90 dB/2.83 Volts/Meter
  • Impedance: 8 Ohms, Minimum 2.9 Ohms
  • Crossover Frequencies: 450 Hz, 2.7 kHz
  • Power Handling: 250 Watts
  • Weight: 39 Pounds
  • Dimensions: 9" H x 34.6" W x 10.3" D
  • MSRP: $2995/each USA; Stand Optional
  • Descent i Subwoofer
  • Design: Sealed Enclosure
  • Drivers: Three 10"
  • Amplifier: One 250 Watt Amplifier for Each Driver; 0.24% THD+N at Full Output
  • MFR: 18 Hz - 120 Hz ± 3 dB
  • Low Pass Filter Frequencies: 30, 35, 45, 55, 65, 80 Hz
  • High Pass Filter Frequencies: Bypass, 40 Hz, 70 Hz
  • Phase control: 0°, 90°, 180°, 270°
  • 25 Hz and 50 Hz Level Control: ±10 dB
  • Inputs: Left/Right RCA Line Level, RCA and XLR LFE, Speaker Level
  • Dimensions: 21.4" H x 20.5" W x 19.9" D
  • Weight: 105 Pounds
  • MSRP: $3495 USA
  • MartinLogan

Design

What is an Electrostatic Speaker?

Electrostatic speakers are essentially a thin ultra-lightweight diaphragm that is suspended between two stators. The diaphragm is positively charged, while the stators (driven by the amplifier) hold opposite charges where one is positive while the other is negative. The alternating polarity of these stators simultaneously pushes and pulls the diaphragm forward or backwards. This movement is what produces the vibrations that are interpreted by the brain as sound. Electrostatic transducers are superior to traditional (cone) drivers is in both mass and distortion.

When a voice coil drives a conventional cone back and forth, increasing levels of distortion occur as the cone achieves greater excursion and becomes harder to control. To reduce this distortion loudspeaker designers use a stiff cone, spider, and surround, which comes with added mass. The resulting inertia created with addition mass results in potential sluggishness when changing direction. As this change in direction can occur up to 40,000 times a second this becomes a significant audible bottleneck. Compare this with an Electrostatic speaker that uses a huge membrane uniformly driven across its entire surface. The larger the radiating surface used, the fewer excursions required to move the air which in turn reduces excursion-related distortion.

Additionally an electrostatic membrane is very thin (12 microns, about the thickness of regular plastic kitchen wrap). This ultra-thin, low-mass design (with almost no inertia to overcome when changing direction) allows electrostatic speakers to be extremely quick and agile when reproducing the electrical input from an amplifier.

Sounds like everyone should use electrostatic membranes doesn't it? Well, this type of driver is not easy to produce and can be limited in low frequency output. As the frequency goes lower, the panel size increases. To get low bass the panel would need to be at least the size of a door. For example, MartinLogan's full-range CLX speaker is six feet tall and two feet wide, and still only goes down to 56Hz. While I like my speakers to be big and large, most listening rooms, and listening partners will not accept such a large monolithic speaker. To address this MartinLogan uses cone drivers to cover the lower frequencies, allowing for more compact designs and room/spouse friendly designs. This comes with its own issues though, as now you have to make the ultra-lightweight, low-distortion panel blend with higher-mass cone. Where this becomes an audible issue is really only at the point at which the panel passes over to the cone. At this cross-over point there could be integration issues. MartinLogan's solution to the problem using only high quality parts in their sophisticated 'Vojtko' cross-over network named after their lead designer. That and they have been working on this issue for over 25years. Their constant refinement of this integration has created a seamless hybrid design.

MartinLogan Home Theater System

Summit X

At the top of the ESL hybrid line is the aptly titled Summit X. The X indicates this is a new version of the original Summit incorporating the 'XStat' panel adopted from the technology found in their premium CLX speakers. While the overall specifications remain unchanged, MartinLogan claims to have improved the crossover, the panel, and the woofer integration. Unfortunately I was unable to obtain a Summit to compare with the Summit X, so my comments refer to the Summit X on its own.

The Summit X boasts a 44" tall panel, two ten inch woofers, each with their own Class-D amplifier housed in a rather compact sealed box. There is a level control (+/- 10dB) at both 25Hz and 50Hz, as well as a control for the LED's on the box that will illuminate the control panel on the back of the woofer box, the MartinLogan logo, and a set of LED's that shine down underneath the box. You can select all, some or none of the lights. This provides zero audible improvement but adds some fun to the speaker. I was happy to note the glow of the LED's was not detrimental to my viewing experience in my darkened theater room.

In the Summit X the crossover is at 270Hz, this is right in the middle of a Tenor, and the cello. At the crossover point the powered front-firing and down-firing 10-inch woofers take over and handle the lowest most octaves. The complex and creative Vojtko crossover adjusts the phase of the drivers near the crossover point to better integrate with the dispersion pattern of the electrostatic panel. The 25Hz and 50Hz level controls were able to counter-act the minor room issues I have, further allowing the Summit X to blend remarkably well with the Descent i subwoofer.

The Summit X is available in many finish options, and is 100% designed and assembled (as of this article) in America. The finish on the Summit X is flawless. The build quality and construction of all the components is indicative of its price tag.

Vista

The bottom of the XStat line up is the Vista hybrid. Designed and assembled in America, with the woofer section being built in China. The Vista uses a smaller panel than the Summit X, a single 8" ported passive woofer section, which combined with the smaller panel moves the crossover point up to 450Hz. This is in the middle of a Soprano and clarinet (among others). The panel is of the same high-quality construction as the Summit X (just smaller is size); however the quality of the cabinet housing the woofer section is noticeably lower quality. The veneer is close in color and tone to the Summit X's, yet it feels less like real wood and more like fake veneer. There is an obvious difference when compared side by side; on its own the difference is hardly noticeable. I did find the finish to be sub-par when compared with other $4000 (and less) speakers such as the B&W 804s, and the Totem Forests.

Ever had one of those Jaw Dropping moments? Well I did the day I put the Vistas up front in place of the Summits. I was expecting to find the Vistas to pale in comparison to the Summit X's, and was I surprised. What I found was that the Vistas are a very capable loudspeaker. Excellent dynamics and resolution, and they paired with the Stage center better than the Summits. Where they lacked was in the bottom end and the upper most top end. The bottom end was compensated for by increasing the low-pass on the Descent i, from 40Hz to 60Hz, and slightly increasing the subwoofer's 50Hz level control. This complimented the Vistas remarkably well. However this also required that the Descent I sub be placed closer to the speakers to improve the integration (which is very room dependent). As for the top end, the clarity and depth of the Vista was not as accurate and involving when compared directly to the Summit X's.

Descent i

An ingenious cabinet design that maximizes driver surface area and minimizes cabinet induced distortion by placing three drivers 120degrees apart in a well braced sealed box. Mounting the drivers in opposition significantly reduces cabinet vibration and the associated distortion that results. Think of two people on a backyard swing-set. If both people swing in unison you can tip the swing set over, when they swing in opposition the resulting forces keep the swing-set stable. Each driver is powered by its own class-d (ICE) amplifier capable of 250watts (RMS) and 700watts (peak) and is servo-controlled to eliminate distortion if it starts to occur. The sub includes +/-10dB level controls at both 25Hz and 50Hz, multiple inputs allowing for simultaneous connections of LFE and stereo, as well as variable phase and crossover.

The only thing that could improve upon this powerful and flexible subwoofer would be a measurement microphone and automatic equalizer. As I have both an auto-eq equipped receiver and a measurement microphone/software system I was able to accurately and effectively set the controls. When paired to the Summit X's I set the crossover to 40Hz, and increased the 25Hz control 2dB and left the 50Hz control flat. This produced a very clean flat bass response that while not the loudest; it is among the best I have ever heard with all types of music and movies.

Stage

Center channels are essential to home theaters, and yet they seem to be an afterthought for most manufactures. It is not enough to just turn a regular speaker on its side. A driver dissipates its sound waves differently in the horizontal plane than its vertical plane. Therefore placing a speaker horizontally changes it's vertical and horizontal dispersion, as now there is a baffle to the sides of the drivers rather than top and bottom. This is even more of an issue with an electrostatic speaker as they have tight horizontal dispersion (also called Controlled Dispersion, see next page) that focuses the sound energy in a tight beam. Placing an Electrostatic speaker on its side greatly reduces its vertical dispersion which reduces the seamless integration necessary for quality home theater audio. To address this the Stage uses three types of drivers, two 6.5inch mid-bass drivers handle from 70Hz to 450Hz, an Electrostatic mid-range handles 450Hz to 2700Hz and then a 1" soft dome tweeter takes it from 2700Hz to the top. On paper one would think this mixing of drivers would create issues, and certainly it would if not for the advanced crossover network that MartinLogan employs.

Overall the Stage is one of the best center channels I have ever heard. This speaker had excellent tonal quality, usable mid-bass and excellent treble. The only problem I found was a slight tonal mismatch between the Summit X's and the Stage. The Stage is a great center, however the mid-range and high-end of the Summit X's is in a whole other league. This issue was most present with multichannel music, and less noticeable with movies. When paired with the Vista there were no tonal issues noticed.

Controlled Dispersion

A speaker driver disperses its sound in a radiated pattern which then causes the sound-pressure waves to hit the floor, ceiling and walls which in turns reflects back towards the listener. This can create some atmospheric effects and contribute to sound-stage and imaging cues. These reflected sounds can interact with the direct sounds from the speaker and confuse the brain and muddy the sound. By reducing the spread of the waves (controlling the dispersion) you can then minimizes late arrival side and ceiling/floor reflections. . This controlled dispersion is one of the major advantages of electrostatics that creates an illusion that you're in the room with the artist/band rather than 'listening to a speaker/recording. The narrower the beam of sound is the less the room will interfere with the direct sound, which can also translate to a very narrow sweet spot. MartinLogan employs a curved electrostatic panel to increase the sweet spot and still benefit from controlling the dispersion.


Set Up

The majority of the listening sessions were done with a Denon 4308 receiver controlling a Bryston 9Bsst2 5 channel amp (140x5watts RMS @ 8ohms). Blu-Ray came from a Sony PS3 slim, SACD came from an Oppo 981HD and 2ch source was an Onix XCD-88 cd player.

The speakers were placed in the room according to the manual's advice, with the Summit X's panel being four feet from the wall, and ample room on both sides as they are open to other rooms (which greatly removes any first side reflection point issues) and slightly toed-in. I ran the Denon's auto-eq (Audyssey) using multiple microphone positions in a figure-8 pattern encompassing the location of my head in the sweet spot. I did this twice, first time I took note of the 25Hz and 50Hz equalization settings that Audyssey applied. I then adjusted the controls on the Summit X's to match what Audyssey recommended (+2db @ 25Hz, +4dB @50Hz). When I re-ran the auto-eq it no longer applied correction to those tow settings. Doing this allows Audyssey to use its finite amount of filters in other frequency bands. For reference sake, the auto-eq set the fronts to large, with no low frequency cut off, the center to small, cut-off at 80Hz and the rears to small, cut-off at 60Hz. The sub's crossover was set to max, and the Denon's bass management took care of sending all the LFE to the sub and all content from 40Hz down (the lowest point that could be set).


In Use

MartinLogan Home Theater System

Now that the hard work was done it was time to put on some music. First up was the multichannel SACD Whites Off Earth Now by The Cowboy Junkies. This is a pristine recording by the crew at Mobile Fidelity Sound Lab. I was immediately struck by a massive and enveloping sound-stage The placement of instruments and their tonal quality was intensely realistic. There was depth to this recording that was previously unresolved with my reference speakers (Raw Acoustic OB3X). The top end of this disc can be too hot with speakers that rise up in the treble, and none of that was found with the Summit X's. As the volume was increased the dynamics did not compress, and the speakers seemingly grew in size, filling my room from comer to corner with clear undistorted sound.

MartinLogan Home Theater System

Switching over to Blu-Ray, I put on David Gilmours Remember That Night. The crowd is lightly mixed into the rear speakers, with the musicians up front. Again the sound-stage and imaging was incredible, and at all volume levels. The panning from front to back was seamless; however across the front stage there was some tonal mismatch between the Summit X and the Stage, with the stage having a slight bump in the upper mid-range this was affected noticeably by the vertical position of the center channel. With other speakers, especially ones that rise in the treble, the crowd's applause can be grating and intrusive. I found no such faults with this 5.1 speaker system.

MartinLogan Home Theater System

On to some 2ch music. To get me in the mood I started with the only album by the now defunct eclectic trio from Canada called Okgiraffe. The band consists of Rosa Smedley on vocals, upright bass and guitar, Kevin Bertram on vocals and upright bass, and Brandon Goodwin on percussion and trumpets. The vocal pairing of these singers intertwined with guitar, upright-bass and percussive instruments on this intimate recording is a great test for dynamics, clarity and separation of instruments. As this album was recorded analog live-off-the-floor, it is also a great test for a systems ability to recreate depth and sound-stage. On the opening track "Black Blood Famine" the upright-bass is what I am listening for. The pluck and release of the strings should be clear and detailed without being lost behind the vocals and the Summit X's nails it. As the upper fundamental frequency of this instrument is very close to the cross-over point I was listening for the cohesion and integration of the woofer and panel. If there was any speed or distortion imbalance it would be present with this instrument, and I heard none. It was seamless and the instrument had full body with great detail. The music on this track comes through with pristine clarity which served to sharply define the notes without any unnatural grain. The small amount of hiss present on this the recording was well resolved with the Summit X's, it was not intrusive or detrimental to the overall presentation.

MartinLogan Home Theater System

For my next 2ch disc I decided on something completely different. It became apparent early on that these speakers could do well-recorded acoustic guitar and female vocals with ease. So what would they do with some sludge-rock done by the original grunge band, The Melvins? Cueing up the 2006 release a Senile Animal I prepared myself for some Electrostatic meltdowns. Seriously, how could a speaker that reproduces excellent recordings so well even begin to do justice to a metal band that made Nirvana look and sound like Easy Listening? I am happy to report they survived. This album features two drummers playing two drum kits on either sides of the sound-stage they play tight, so tight in fact that you would think there was only one drummer. Until I heard them through the Summit X's I had never heard the tonal differences in their percussive instruments. There is ever so slight difference between the two kits and it is clear and well reproduced with these speakers. This is not the cleanest recording and at high volumes it is apparent. However these speakers can and do rock, and while they lack some of the dynamic punch provided by cone drivers they get plenty loud and very satisfying without any fatigue.

MartinLogan Home Theater System

Throwing the extended cut of The Watchmen in DTS-HD 5.1 into the Blu-Ray player I was not prepared for just how well these speakers could do movie playback. When Dr. Manhattan teleports the resulting shock wave put the Descent i into action. The bass was clean, and unlocalizable. Thanks in part to the low cross over setting afforded by the truly full-range Summit X's, and also in part to the excellent cabinet design. It was not possible to locate the source of this low frequency and instead the entire listening room seemed to will with bass. The sound was clean and flat without any nasty resonance. You could feel the bass from ten feet away through the couch. In the past I had employed bass shakers to move the seats. With the Descent i I found no need to augment anything. The panning of sounds across the front stage was more balanced with movies than music, and there were no issues from front to back. The glass breaking and gun shots (of which there is plenty in this movie) was startling realistic. Pleasantly I heard no audible compression or distortion.

Just for fun I took the Bryston out of the chain and used the amplifiers in the Denon 4308 receiver. I expected one, or both of the following. Thermal shutdown of the Denon under the load, and mediocre sound reproduction. Many a pixel has been spent talking about how hard MartinLogan's are to drive. How you need high-quality gear and power to make them shine. Maybe something has change with the new line, but I had no problem with just a receiver powering the set. And I did not go easy on the Denon. I went back and revisited the tracks and movies I used with the Bryston. What I found was that at low to mid volume the Bryston seemed to better control and excite the panels. While the Denon sounded it best at higher volumes. As well when I really pushed the speakers loud the Denon started to break-up and add some grain to complex percussion passages.

All was not perfect though. There is one issue with line-source, and electrostatic speakers in general that may deter some listeners. And that is the tight sweet spot. Everywhere outside of the sweet spot sound great, just lacked imaging and sound-staging cues. If you are off to one side the image pulls to that speaker. But what a sweet spot. With my usual speakers (ribbon tweeters paired with an open-baffle cone mid-range) the sweet spot is generous, maybe two and a half seats wide. With both the Summit X's and the Vistas I found the sweet spot to be about one and a half seats wide. Yet it was phenomenal in that spot. Keep this in mind when you audition MartinLogan speakers. For me it was a non issue as I am the only one in my home who even cares about such things. And with movie playback the Stage does a great job of locking the voices dead center, even when you are off-axis.


Conclusions

I have long felt that to get great sound one should focus on the speaker's first, room second and electronics third. This is not in agreement of many reviewers, manufactures or consumers. Many people feel that garbage in = garbage out. And they always suggest using the best source, the best amp, and in some cases the best cables, and then adding the speakers that work well. You cannot deny however that the biggest and most noticeable difference in all the components we use is with speakers. It is not easy to detect the differences between cd players, yet astonishingly easy to hear the differences between speakers. Personally I want my electronics to be flat and leave the colorization of the sound to the speakers.

And with that in mind, I absolutely recommend the MartinLogan speakers. I was able to drive them with expensive and budget gear, with good and bad recordings and had fun throughout it all. In the end you must realize electrostatic speakers require the proper room, and their sound is not for everyone. Their narrow sweet spot may deter some listeners, so you must audition for yourself. They are for me, and I now know why they call us Panel Lovers.