Magnepan MG-20 loudspeaker Page 2

Because I'd heard some nice things about the Ayre Acoustics V-3 as a partner for the MG-20, I asked for a loaner unit. This moderately priced stereo power amplifier ($3450) features a purist and innovative design with no global negative feedback, and displayed a giant-sized sweet spot through the upper mids. It managed to vitalize the MG-20's mid and upper registers with speed and transient finesse, while dishing out refined harmonic textures. Detail resolution and layering of the depth perspective were also strong suits. Despite its rating of 200Wpc into 4 ohms, the V-3 evinced dynamic compression when driving the MG-20 from loud to very loud—a task neither the Bryston nor the Classé had any trouble with.

The smoothest and sweetest solid-state drive I was able to find was the Pass Laboratories Aleph Null monoblocks. The Alephs run single-ended class-A up to about 40W, at which point operation shifts to class-A push-pull out to 75W into 8 ohms, and 150W into 4 ohms. While the Alephs don't exactly sound like SE triode amps, they do share the latter's disposition toward pure and liquid harmonic textures. Treble transients were so well-delineated, with perfect control and felicitous decay into the noise floor of the recording, that it suddenly hit me that the Aleph is a breakthrough product. It coaxed an amazing degree of low-level detail from the MG-20s without resorting to cheap tricks like etching or brightening textures so as to artificially enhance detail.

Preserving the crispness of live music without totally toasting harmonic textures is quite a feat. Reproduction of the corpus of a violin was particularly noteworthy. For example, Perlman and Zuckerman performing Bach's Double Concerto (EMI CDC 47856 2) never sounded more convincing. Soundstage transparency was such that I could clearly see its inner recesses. Instrumental outlines ebbed and flowed with lovely dynamic bloom. But, as with the Ayre Acoustics V-3, the Alephs also occasionally ran out of headroom when driving the MG-20s from loud to very loud.

All about tonal balance
The Magneplanar's strongest tonal suit was a full-bodied lower-midrange/upper-bass that fleshed out the power range of an orchestra—ie, up to about 500Hz—with justice for all. Reproduction of cello was especially impressive: gutsy, and rhythmically precise—no boxy resonances to smear pitch and intonation. I guarantee you this: anyone who's spent their audio career listening to boxes will no doubt marvel at the fact that such airy, detailed, and precise bass lines are possible in a speaker. However, there was no getting away from the fact that the lower midrange was emphasized in relation to the mids and treble.

In my room, deep-bass extension was only flat to 40Hz. Presumably, it would have been possible to coax the bass response into the low 30s with speaker positions nearer the wall, but only at the expense of imaging precision. While the impression of bass punch was adequate, I became aware of moderate dynamic compression when the MG-20's woofer was confronted with a bass transient. In the realm of full-range planars, I'd judge the MG-20 a top performer in this department. However, when challenged by top-of-the-line cone woofers, the inevitable conclusion was that, as with other planars, bass dynamic range was restricted. The concussive clout of the best cone woofers (eg, the Genesis II.5) is not easily forgotten—that sort of impact and sheer intimidation were lacking with the MG-20.

The MG-20's mid-treble (the 3kHz–10kHz range) sounded slightly recessed, on the order of 2dB down relative to the rest of the spectrum. The perspective was consistently that from Row R, the effect being a slight and natural dulling of the brilliance and presence regions that mimicked a back-of-the-hall tonal character.

Closely miked soprano voice, which should have sounded quite brilliant, was typically a bit less lively. In this respect, I preferred the Sound-Lab A-1's sunnier disposition. The A-1's harmonic sunshine and transient finesse painted the 3kHz–10kHz range with greater lucidity. The degree of verve and dramatic fire in the MG-20's sound were to some extent impacted by the associated gear. A brighter-sounding amp or front end, for example, subjectively worked better in this regard.

The joy of cooking
The similarities between gourmet cooking and bi-amping are unmistakable: The cook/audiophile is given a free hand to mix ingredients (amps and crossovers), concocting a final dish seasoned to his liking. The possibilities are enormous: the owner can experiment with crossovers, crossover frequencies, filter slopes, and power amplifiers.

To constrain the enormity of the choice, I chose the Bryston 10B electronic crossover as the standard for this review. And while I tried a mixture of tube and solid-state amps (tubes for the top octaves, solid-state for the bottom), I did most of my listening with two pairs of Bryston 7Bs, because they worked so well with the Magneplanars driven full-range.

I settled on 18dB/octave high- and low-pass slopes at 200Hz as optimum—I didn't find the owner's manual's suggestion of 6dB and 300Hz to work as well for the high-pass signal to the midrange/tweeter. In the lower octaves, 18dB filter slopes tended toward the ideal because of their good selectivity and decent phase behavior.

The most obvious and immediate sonic benefit was a greater sense of ease through the midrange—as if the mids were able to breathe louder. When pushed hard, there appeared to be fewer distortion products than with the passive crossover network. There was a much lower perception of strain during loud passages. Clarity of harmonic textures also improved a notch, as the layering of complex passages was more readily resolvable.

I was also able to tweak the high-pass signal level 1–2dB, thus improving the perceived tonal balance through the upper-mids/presence regions. More boost than that, however, tended to over-brighten the treble.

Conclusion
Planar power! Fed by a high-calorie power amplifier, the Magneplanar MG-20 succeeded admirably in painting a cohesive, living soundstage populated by instrumental outlines of realistic proportion. Its other special gift lay in its natural portrayal of harmonic textures and dynamic bloom. The MG-20's robust tonal balance makes it a natural, of course, for accommodating a variety of music—from Bach to the Beatles.

Although the passive network makes for a cost-effective alternative, the full glory of the MG-20 was only realized when the speaker was bi-amped with high-quality components. A subwoofer would extend the bass response to 20Hz, and increase the bass's overall dynamic range—in which case you might consider tri-amping.

Even in its plain vanilla configuration with the passive network, the MG-20 was a world-class speaker, and one which has justly earned my respect. I could live happily with this speaker until the end of time.

COMPANY INFO
Magnepan
1645 Ninth Street
White Bear Lake
MN 55110
(612) 426-1645
ARTICLE CONTENTS

COMMENTS
yooperaudio's picture

A TWENTY-FOUR year old article is posted here, with some kind of assumption that it will be valued? Jesus god - get a grip.

John Atkinson's picture
yooperaudio wrote:
A TWENTY-FOUR year old article is posted here, with some kind of assumption that it will be valued?

This review is of what was at that time Magnepan's flagship loudspeaker and will be of interest to many. When we launched our website, our plan was to post every review that had been published in Stereophile to our on-line archives and we are well on the way to achieving that goal.

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture

The latest version is 20.7 .......May be Stereophile could review them? :-) .........

Bogolu Haranath's picture

"Get a Grip" ......... Aerosmith :-) ........

JRT's picture

I thank you and/or others responsible for posting this interesting content.

My comment here is intended as counterbalance to complaints about posting older articles.

Respectfully,
JRT

prerich45's picture

Bravo!!!!!! I enjoy reading blast from the past!!!! Especially the Infinity Composition Prelude PFR and the MTS reviews!!!!

Jim Austin's picture

We respect tradition, and history, and our elders.

Plus, whatever you might think, these historic articles are widely and enthusiastically read.

Jim Austin, Editor
Stereophile

yooperaudio's picture

Oh please. What a load of BS. Elders? Fuck your pomposity and your lawn.

Jim Austin's picture

You cannot make him drink.

I'm thinking our site is a poor match for you. Do you agree?

Jim Austin, Editor
Stereophile

yooperaudio's picture

Happily, yes. Carry on with your self-aggrandizing myth-making. You’re grand!

Jim Austin's picture

Excellent. I'm glad we agree. Goodbye.

Jim Austin, Editor
Stereophile

scottsol's picture

Unlike printed magazines where editorial page count is limited by ad revenues, posting old reviews has no effect on the number of posts with new information.

Moreover, in the many years that Stereophile has been posting old material they have typically received more reader comments than new material.

So, your comment was not only of no possible significance, but completely wrongheaded in its premise.

Bogolu Haranath's picture

DO's description of 'Planar Imaging', with JA1's comments, are an interesting read :-) .........

gcvanwinkle's picture

The $650 LRS OWNS the older Model 20 in terms of time coherent performance:

https://www.stereophile.com/content/magnepan-lrs-loudspeaker-measurements

The use of a first-order crossover pays off - along with a little care in speaker placement. Now test a newer 3-way Magnepan and see if they can do the same trick with a more complex design.

And thanks for the look back in time!

volvic's picture

Back in 1989 I auditioned what I thought was going to be my final turntable purchase, it was between the Linn LP-12 and Roksan Xerxes. The speakers used were the large Maggies, I believe they may have been the 20's or at the very least the precursors to the 20's reviewed above. The speakers and Bryston electronics were revealing enough to let me make my decision. I can still remember the addictive sound they had and if I had space in my Manhattan apt I would have swapped my Kans for a pair of Maggies. Love that Stereophile releases these old reviews. Takes me back to a time when physical media was king and when retail hi-fi stores were more plentiful.

BDP24's picture

yooperaudio's comments certainly mirror the unnecessary nastiness I see in so much social interaction these days. Dick Olsher has long been amongst my two or three favorite hi-fi critics of all time, and much of what he had to say about the MG20 is timeless, and still relevant today. I happen to own a pair of Tympani T-IVa, which can be viewed as the basic blueprint for the current Maggie flagship, the MG30.7. Thanks for the reprint, though I still have my copy of the issue it appeared in. A Stereophile subscriber since 1972!

dial's picture

Interesting, I owned a pair of III A (bought second-hand), sold them to a friend cos the WAF you know. They still sound great, with Audio Analyse pre & amp and a Goldmund studio one (extremely rare, only seen it once ! I have the 2)/Linn Basik+/Sumiko Blue Point 2 ! They were not as fragile as the Apogées (see the AS H-E Audio site).

Big eugene's picture

Re: yooperaudio. Wow....what an absolutely pathological, colossal, jerk. No real arguments, just pejoratives.
If this is what passes for civility these days, we're finished as a society.

David Harper's picture

another interesting read would be a review of the original Acoustat monitor, the one that resembled the black monolith in "2001". My friend had a pair of these and they sounded amazing.

scottsol's picture

The Acoustat model that most closely resembled the 2001 monolith was the 2+2 which arrived five years after the first Acoustat. Ironically, they bore a far greater resemblance to that monolith than the first Martin Logan speaker, the Monolith.
https://www.stereophile.com/content/acoustat-22-loudspeaker

David Harper's picture

maybe those were the ones my friend had. I just ordered the new maggie LRS.

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