You are reading the older HTML site

Positive Feedback ISSUE 39
september/october 2008



MG-20 loudspeakers

as reviewed by Arnis Balgalvis





Avalon Eidolon.

Marantz MA-9S2 monoblock power amplifiers

Sony SCD-1 CD/SACD Player, a Nova Physics Memory Player, a Music Server with a Lynx sound card and Media Monkey software. Technology Corporation Platinum DAC III with the optional Analog Volume control, optional Signature DAC module and the Signature 32x filter upgrades, and a Berkeley Audio Design alpha-DAC,

Interconnects are TARA Labs AES/EBU 2M. Speaker cables are TARA Labs OMEGA 10 foot long. Digital cable is Wireworld Gold Starlight AES/EBU 1.5M,

Echo Buster Panels, RSC Tube Traps. Installed dedicated AC power line using 8 GA wiring. Black Noise AC Power Filter/Conditioners.


In a very short time Esoteric has established itself as one of the most prominent companies in the high end arena. They are a force to be reckoned with not only because of the outstanding CD and DVD players that they have created and ship in great numbers, but, to round out their lineup, they also have introduced significant analog products. Witness the C-03 Linestage Preamplifier and the A-100 tube power amplifier.

And then at the 2007 CES, Voila! Esoteric displayed the MG-10 and the MG-20 loudspeakers. For me, this particular launch of an exciting product ranks with the most significant CES introductions that I have had over the years. Of course, it had to happen sooner or later—Esoteric had been unveiling new products on a regular basis. Up to that point, they had everything else to complete a system—yes, even cables—so why not speakers.

At that first hearing of the MG-20, it was immediately apparent that this new speaker was very special. The exceptional speed, the transparency, the dynamics, and, yes, power, all gelled in a very seamlessly coherent and effortless manner.

This was a presentation that created an immediate buzz right then and there—many of the press corps could be heard muttering among themselves in admiration of this new speaker prodigy.

Of course, I wanted to review this new marvel. However, the MG-20s were back ordered to fill the initial dealer requests. I was put in the queue and it was not until some months ago that a review pair finally arrived.

The Big Picture

The initial concept and the project coordination for the MG-10 and MG-20 loudspeakers was all Esoteric. Once Mr. Omachi, president of Esoteric, decided to launch a line of loudspeakers, he proceeded to engage a number of essential contributors around him, in addition to his R&D department, in order to achieve that goal.

So, for example, the development of the revolutionary speaker driver material and key proprietary coatings took place at Nippon Kinzoku Co., Ltd, a Japanese company specializing in the art of exotic material and chemical research and development.

Then, to fully integrate the whole design and implementation, Esoteric called on Tannoy, Ltd. U.K., a renowned stalwart for decades in the loudspeaker industry and familiar associate. Esoteric has been the distributor of Tannoy products in Japan for many years.

The fact that the development of the MG-series loudspeakers was a joint effort by three companies is very significant. Something like this does not happen very often in high end, what with the egos and the "not invented here" syndrome dominating the scene.

What's It All About

The heart of the matter of the MG-20 is the breakthrough decision to use Magnesium as the material for the loudspeaker diaphragms.

Magnesium per se is not a practical metal. Though it has a host of the desirable characteristics essential for a near ideal cone material—very light weight, exceedingly stiff, great self-damping and sonic propagation—it will oxidize quickly as soon as it encounters oxygen in the atmosphere.

Here's where Nippon Kinzoku Co., Ltd. came in. Working with Esoteric, they developed a proprietary method for the application a micro-thin layer of clear coat and ceramic. This process produces a couple of very significant advantages: first, the magnesium is prevented from oxidizing and, second, its already outstanding self-damping characteristics are enhanced even more.

The result of this research generated two new innovative drive-units: a 6.5" woofer and a 1" tweeter.

Being that the woofer crosses over to the tweeter at 1.9kHz, calling this driver a woofer is quite a misnomer.

The Esoteric Mg woofer/midrange driver is designed to excel in power handling capacity and to possess wide dynamic range, in addition to having very low distortion products. To that end this woofer/midrange driver incorporates a robust die cast chassis and a substantial magnet assembly.

Furthermore, in order to control the break-up behavior, the shape of the woofer/midrange driver cone is corrugated. Control of the Mg cone motion is enhanced by the optimally incorporated half-roll rubber surround to provide excellent compliance and linearity characteristics.

The Mg tweeter for the MG-20 is the beneficiary of a proprietary forming process developed for piston production. Here the ceramic coating for the dome diaphragm produces a driver with a very high stiffness to mass ratio in addition to its exceedingly low mass. The well controlled resonance is pushed way out to well beyond 40kHz. A powerful ferrite magnet provides the flux force for the precisely layered copper clad aluminum coil that energizes the Mg dome of the tweeter. This remarkable tweeter reaches down smoothly to 1.8kHz and stays flat for 4 octaves out to about 40kHz. Wow!

It is a well established tenet that the ideal driver should not exhibit distortion creating breakup modes. For these diaphragms, behavior as true pistons well before and also well beyond the specific range of the desired operating spectrum is an absolute must. Furthermore, breakup modes must be avoided in the regions where the crossover is rolling off the response. If anomalies are allowed here, even though they may be at low magnitudes, they will be heard. In today's world, speakers have to be as free of distortion as possible.

It follows that even if a glitch is tens of dB down, it will still interfere with the reproduction. Thus, true pistonic behavior is a must. And that quest leads to specialized materials, in this case Magnesium, which will withstand without any give the violent driving forces that are generated during the playback process.

The MG-20 demonstrates what is possible when the drivers function close to ideal. The crossover design can be simpler since fewer anomalies outside of the driver pass-band need compensation. Suddenly, the dynamics have more zest as they spring to life effortlessly. This allows the sound to be imbued with that essential sense of aliveness which brings us closer to the real experience.


The MG-20 is a slim floor-standing column loudspeaker with very practical dimensions and weight. The 41 3/4 inches high and 10 11/16 inches deep cabinet has a trapezoidal shape 8 1/2 wide at the front and narrowing down to a 6 3/8" wide rear panel. The MG-20 comes with a platform-like stand, the STMG-20, that fastens to the bottom of the speaker with 4 bolts. This stand has three floating support discs that contain inverted cone like spikes. They act to create a stable support for the MG-20 speaker by coupling the speaker cabinet to the floor. The resulting foot-print is a very user friendly 12 ¼ by 10 ¼ area.

The speaker proper is a straightforward, yet elegant, design. The first hint that we have something special is the beautiful wood. On its exterior the MG-20 has a beautiful cherry wood veneer. This cherry is also used for the vertical side rails on either side of the front baffle. But the best part is not obvious—the front baffle holding the two woofers and the tweeter firmly in place, is 1 inch thick and the cabinet walls are actually 15mm thick birch plywood. Overall, the fit and finish is excellent.

Of course, the cabinet is braced extensively on the inside. I suspect that the resulting good performance of this speaker is due to the choice of these woods instead of the mundane MDF.

The MG-20 uses two woofers and one tweeter arranged in a vertical array with the tweeter placed between the woofers. The front baffle is slightly contoured to accommodate the width of the woofer frame. The speaker comes with a stylish grill that covers the three drivers and the reflex port. It is just narrow enough to expose a portion of the woofer basket's outer rim thus creating a techy yet elegant look.

The sensitivity is specified at 89dB. For impedance Esoteric quotes 6 ohms nominally, with 3.7 ohm minimum. See Figure 1. It is a ported design, where the circular vent exits on the front panel. The internal volume is 21.5 liters.

MG-20 Input Impedance

Esoteric has implemented a low-loss and thermally stable cross-over network for the MG-20 using ICW polypropylene "Clarity Cap" capacitors for the high frequency feed and large, laminated silicone steel core inductors in the low-frequency path for the woofer. The wiring is all point-to-point with silver plated van den Hull conductors. The crossover uses 2nd order slopes for the woofer low-pass network and 3rd order for the tweeter high-pass filter.

Response curves, as supplied by Esoteric, are shown in Figure 2. Distortion characteristics are shown in Fig. 3 – 5, while the polar response measurements appear in Fig. 7 – 9.

MG-20 Frequency Response

MG-20 System Vertical Polar

MG-20 LF Vertical Polar

MG-20 HF Vertical Polar

MG-20 Distortion

Red 2nd Harmonic, Blue 3rd Harmonic, Raised 30dB

MG-20 LF Distortion

Red 2nd Harmonic, Blue 3rd Harmonic, Raised 30dB

MG-20 HF Distortion

Red 2nd Harmonic, Blue 3rd Harmonic, Raised 30dB

Bi-wire terminals are located on the rear panel shown in Fig. 6. Additionally, a grounding or "earth" terminal is also provided for the speakers. Esoteric feel that a properly grounded speaker chassis will keep the RF interference to a minimum resulting "in a more transparent midrange".

The MG-20 weighs in at 33 pounds where the STMG-20 stand adds another 9 lbs per speaker for a total of 42 lbs.

Set-up and Tests

I auditioned the MG-20s under three sets of conditions. Obviously, there is my listening room. But I also took the speakers to my friend Bob Gerard's place. Bob just happens to be an excellent listener with a great basement listening room which, not surprisingly, is completely different from mine.

While my system tends to be reasonably exotic, Bob's components are more modest and very cost effective. This situation allowed me to hear the speakers driven by the Dyna MkIII tube power amps, but, most importantly, in a completely contrasting acoustic environment.

The third place was CES.

CES? Yes, absolutely. As it happens, the Esoteric CES demos of 2007, as well as 2008, were outstanding. Driven by, of course, an all Esoteric chain, the speakers acquitted themselves just great. This provided me with yet another take on this product.

Of course, I was excited when the MG-20s arrived. I noticed that the speakers were packaged with unusually great care. They were carefully wrapped in a plastic sleeve and arrived in a double boxed container. The speaker stands arrived in a separate box.

But all that glitters is not gold. The good news was that I had the speakers. The bad news was that I was faced with the dreaded break in process. These speakers need to be exercised a good 200 hours before they are ready to start performing properly. So, I unpacked the MG-20s and proceeded to feed them a constant diet of music. Apparently there is more than one way to skin a cat, or, in this case, to break in the MG-20s. Or, for that matter, all speakers. Mark Gurvey, Division VP/Esoteric, Teac America, Inc. clued me in about a way to accelerate this tedious process.

What I needed, he told me, was the Isotek Full System Enhancer & Rejuvenation Disk. Not only could I cut down on the burn-in time, but the effectiveness of the break in would be superior to any other signal used to exercise the speaker. I proceeded to obtain this CD from the good folks at Isotek and put it to good use. Was it as effective as Mark had suggested? I have no clue; I could not perform anything resembling a controlled test on the single pair of MG-20s that I had been sent.

Location, Location, Location

In my room, for starters, I placed the speakers in the approximate location where my Eidolons usually sit. All my listening was done with the grilles removed.

My initial results were impressive and I decided to continue with this location. However, my listening area is carpeted and the very carefully crafted support feet of the STMG-20 base ended up being practically useless in this situation. The give of the carpet and the form under it did not provide any semblance of stability necessary for anchoring the speakers firmly.

Initially I had screwed the four threaded spikes in the threaded holes in bottom of the speaker and tried to audition them that way. Yes, the spikes did pierce the carpet (but only after filing them down to very fine point), but the speakers, being top heavy – the drivers are at the top part of the speaker—produced a very precarious set-up that made me rather nervous.

It did not help that the 4 bottom spikes were difficult to adjust so that all 4 touched the floor at the same time. So, the spike approach was bid a definite bye-bye.

My solution was to place each MG-20, with its mounting base firmly attached, on an 18" by 18" by 2" thick concrete-like block—actually a patio tile—which itself was supported by three Avalon Acoustics stainless steel cones. I have found these cones to be particularly handy because they have a pointed configuration that is great for piercing carpets and because they "sound" wonderful.

So, in summary, three cones support this patio tile and couples it to the concrete floor in my basement, and the MG-20 with its STMG-20 base plate sits on top of it. Since the tile weighs 50 pounds, this method of anchoring the 42 pound speaker and stand was very effective. The 18" by 18" area of the tile afforded me reasonable leeway for positioning the speaker for best placement and for tailoring the toe-in/toe-out settings to try to extract good sonic performance. After further listening I decided to slip an Ayre Myrtlewood block under each leg of each of the MG-20 support stands. This brought the slight tendency for a high end exuberance under control.

Yes, I did try to set the speakers up in the manner suggested in the manual where the speaker axis cross in front of the listening position. But I could not make that set-up work effectively in my room.

In my listening room the MG-20s ended up firing just past my ears, i.e. they were toed out slightly so that I could just see the inside wall of the cabinet from my listening position. The distance between the speakers was 8 ½ feet with each speaker sitting 8 ½ feet to the listening position. There is an interval of 10 feet from the speakers to the wall behind them.

Since my listening room is not symmetrical, the left speaker was 30" from the side wall, while the right speaker had lots of space to its outside. I placed a 24 by 48 inch Echobuster absorptive panel on that side in an attempt to provide some semblance of symmetrical acoustic loading.


The most outstanding aspect of the MG-20 is its sense of speed, clarity and openness. This had been my impression at the initial unveiling at CES and it was only reinforced as the listening continued.

This speaker's forte is all about smoothness, purity and refinement while avoiding the realm of the etched and the mechanical. For me, coloration is not a concept that I would associate with the MG-20s.

I should mention that for all listening the Memory Player from Nova Physics, Inc. was the primary source while another music server was used to play some of the exceptional 176.4/24 source material. I wrote about the Memory Player product in PFO about two years ago and find it to perform even better today than what I described then. You see, it is a much improved product due to the Build 7 upgrade that was released a year ago.

The MG-20s are also exceptionally adept at conveying minute subtleties and nuances thus allowing the sophistication of timbres and dynamic shadings to materialize in a palpably pronounced manner. As a result, I found the MG-20 to be one the most involving speakers that I have ever heard.

Another aspect of note for me was that the purity and refinement that I found so impressive, is something that prevails right across its whole and very extended spectrum. This is not a speaker with merely wonderful highs, or a great midrange, or superb bass. No, what's remarkable about the MG-20s is that this outstanding performance aspect is an across the board phenomenon. The bass is taut and firm, the mids are open and engaging, and the highs are crisp and clear, and delicately delineated.

To some, I'm afraid, Esoteric's choice of metal drivers might be cause for concern. I say, forget about that stigma—that is not what I heard. The MG-20 is NOT one of those novel high technology marvels that is fast and revealing and transparent, only to end up sounding etched and clinical. Nor is it a speaker that despite having been fed carefully selected material, still proceeds to distance you from the music.

Far from it. The MG-20s can swing and sway to all music while providing an involving and inviting experience. Their ability to extract the essential qualities of music in an exciting and stirring manner placed them in a very elite high performance category of speakers.

While the transparency and speed of the MG-20 did remind me of electrostatics, their dynamic capability sets them way ahead of that genre. The MG-20 can really keep pace with the best of the dynamic lot. But, along the lines of what an electrostatic can do, this speaker really shines when it comes to replicating artful dynamic shadings and the complexities of sophisticated tonal balances. All essential subtleties that take us closer to the intimate musical intimations of the musicians.

That is, however, as long as the expectation of low bass remains reasonable. I certainly would not use the MG-20s to play disco or similar music that demands a certain degree of the ability to kick butt.

From what I've heard, the MG-20s are more comfortable with a chamber ensemble than a full orchestra. It is more like a cello and not a double bass. And don't take that as a slight. I mean, the speaker is rated -6dB down at 38Hz. Obviously, it was never designed to rock the house.

I think that the home theater experience has corrupted our sense of bass performance expectations. The blown out of proportion slams and crashes that are the essence of many sound tracks, are very rarely encountered at concerts with unamplified instruments.

Since I don't have a home theater and I do attend at least a dozen live music events each year, I do not see myself as one of the corrupted ones. At least in this one regard.

So, while on the business of MG-20 bass, I would like to refer to a pertinent experience I had a long time ago while trying to find a sub-woofer for my ESL-63s. I ran a number of the then renowned subs through the paces, including the well regarded Entecs, but to no avail. Whatever I tried, did not gel well with the great speed and transparency of the Quads. I consequently abandoned my search for a woofer and went about enjoying what the ESL-63s had to offer.

And so it is with the MG-20s. What they have going for them with their speed and transparency and imaging far outweighs the need to seek rock bottom bass. The more I listen the more I realize that its essentials have been refined to a very high level and the speaker can easily stand on its own merits.

Here's the good news: the MG-20 is an exceptionally delectable performer right down to those lower reaches that it was designed for. What it has going for it is an ability to stay coherent and clear in its pass-band. That means the MG-20s stay clean, and I mean delectably clean, down to a very reasonable point where they then begin to roll off in a very outright and controlled manner. The MG-20s are subtractive, unlike many other speakers that start to whimper and strain and muddy up the sound outside of their capability.

For example, on the recordings that I know well, the Zigeunerweisen track of "Uncommon Ritual ", (Sony Classical xxxxx), I never felt shortchanged in the bass department. If anything, the opposite was true, I was thrilled. What I heard was a resoundingly resolved, transparent, and very fast sound, especially that of the double bass, that more than compensated for whatever might have been abbreviated in the bass region. I simply did not miss anything. The dynamic excursions, the absolutely captivating staging, and the snap of the mandolin just plain set me on the edge of my seat and drew me into the performance. I was mesmerized to hear how delicately the attack of each pluck transitioned into an airy absence; time was near a standstill as each decay proceeded to die away into an eerie silence.

But don't mistake this delicacy for weakness. The MG-20s take no prisoners when it comes to revealing bright or sibilant recordings and display them in a very revealing light. Much to my dismay, I found that Eva Cassidy's Songbird , (Blix Street Records G2-10045) while very ambient, was rife with rather exaggerated sibilants and peaky passages during loud parts.

Play well recorded material and the MG-20s will provide you with exalted levels of transparency. For me, when playing numerous of my favorite CDs, this speaker provided some of the best immediacy ever. That includes speakers like the Avalon Eidolons and Eclipses, the Apogee Divas, and the Quad ESL-63s

The longer I listened to the MG-20s the more I liked them. These speakers really grew on me. And because I had them for a fairly long time, there were several components that found their way into the system and helped to make the sound better. One was the alpha-DAC by Berkeley Audio Design and the other was the Black Noise Extreme mains filter distributed by Nu-force. Both of these components allowed me to feed the speakers a more refined and elegant signal that revealed the capabilities of the MG-20s.

The speakers responded to this challenge most commendably. The MG-20s revealed a host of sophisticated nuances and hues with exceptional élan. This was not only about revealing more details, this was about the ability to make these subtleties more significant in a very expressive manner. And imaging and focus, both of very high caliber to begin with, now moved into the stunning category judging from the spectacular soundstage that was being generated consistently.

And another thing: I simply can not detect a cross-over. Had I not known that it was a two-way design, I would never have guessed that to be so. It does help, I'm sure, that the woofer and the tweeter use the same material and technology because the end result is a completely seamless musical presentation. The MG-20s simply excel at disappearing. Time and again, I found it rather uncanny to hear this wonderful soundscape materialize in front of me without much of a hint that it is created by speakers.

The real fun, however, began when I hit the MG-20s with some of Keith Johnson's HRx recordings. Reference Recordings has now released 5 DVD-R discs that contain exact, bit-by-bit copies of Keith's 176.4/24 masters. Talk about a special treat! The good news is that these DVD-Rs are now available. To play them you do need a computer/music server with appropriate software and sound card as well as your own DAC. (I intend to cover the HRx recordings and the hi-rez music server subject in the, hopefully, near future.)

The exceptional high frequency resolution and speed capabilities of the MG-20s really rose to the occasion and produced a most memorable sonic experience. The vastness of the recording venue was recreated by the MG-20s with great effectiveness. And the orchestral breath and spread and depth were depicted in stunningly realistic proportions that materialized in an involving presence. Couple that with the remarkably refined timbral reproduction, with some pretty heartening excursions into the realm of dynamics, and I have to award this speaker all of the five stars that I have chosen to have available to me.


Esoteric has created an exceptionally refined loudspeaker in the MG-20. I found it to be a speaker capable of delivering outstanding musical pleasure. The MG-20s provided me with one of the most open, vivid and transparent windows to the performance that I have ever had in my home. It's a speaker that flatters the music.

In closing, I have a really exciting development to announce, something just in from Esoteric: the price of a pair of MG-20s with stands is now $7800! According to Mark Gurvey: "All R&D amortization now completely paid off." (Only a few months ago the MG-20s had an MRSP of $9000/pair and the STD-MG20 stands were option with an MSRP of $1500.) I was going to recommend the MG-20s wholeheartedly before the arrival of this wonderful announcement, but now, at the $7800 price (with stands), I see this speaker as one of the outright best buys in all of high-end. As such, it is a must-audition product in every sense of the word. Arnis Balgalvis

MG-20 loudspeakers
Retail: $7800 a pair (stands included)

web address: