Magnepan 20.7 Loudspeaker

Unprecedented Full-Range Planar Sound

Equipment report
Categories:
Floorstanding
|
Products:
Magnepan 20.7
Magnepan 20.7 Loudspeaker

Because of the line-source dispersion characteristics of the 20.7s, only a relatively small amount of their sound output is radiated toward the ceiling and floor. This has the desirable effect of minimizing unwanted reflections from the floor and ceiling, compared to a point-source speaker. Further, the midrange driver and tweeter tend to produce most of their energy on-axis, so sidewall reflections are considerably reduced as well. All of this helps with imaging and accuracy of the soundstage. It also minimizes (but may not completely eliminate) the need to make adjustments to the room.

How Are the 20.7s Different from the 20.1s?
I wish I could fully answer that question. Wendell Diller, great host that he was, was almost mum on the physical differences between the 20.7s and their predecessors. Very frustrating, to say the least. All I could get out of him was that they used higher quality capacitors in the crossover and to “listen and you will hear.” But I did learn from Jonathan Valin’s excellent 2012 blog about the 20.7s (highly recommended reading), and also from the folks at Audio Research, that the midrange driver in the 20.7 is new, with half the mass of the quasi-ribbon panel in the 3.7s. That may help explain the more seamless blend between midrange and tweeter, definitely smoother in that respect than the 20.1s. The crossover is also new and, after break-in, seems to be one of the major contributors to the success of the 20.7s.

There are also some physical differences between the 20.7s and its predecessors that are readily apparent to the user. First, Magnepan finally has done away with the bulky and seemingly power-hungry external crossover. The crossover network is now entirely built into the speaker. This makes initial setup much easier. The connections at the rear of the speaker have also changed slightly. In the 20.1s, there is a connector for loudspeaker cable that works best with banana plugs. The 20.1s have a similar connection that can also be used to insert resistor leads for the purpose of slightly attenuating the output of the tweeter. Magnepan does supply resistors for that purpose, although I have achieved very slightly smoother sound by using several high-quality resistors in parallel to achieve the desired value, such as one ohm. Magnepan supplies a thick metal bar to insert in place of a resistor if you choose not to attenuate the tweeter. Again, I have obtained a very slight sonic improvement over this bar by using a high-quality speaker jumper. Since my speaker cables are Audioquest Volcano, I also use Volcano jumpers made for this purpose.

The 20.7s continue with the same connection protocol, except now there is an additional input in which to insert a resistor to attenuate the output of the midrange panel. I tried a resistor in this location for only a short period of time before deciding that midrange attenuation was not the way to go, particularly in light of the substantial output of the bass panel. So I use another Volcano jumper at this location. The last readily observed change to the 20.7s is the elimination of the metal feet at the base of the speaker. In their place is a new oval shaped wooden base, about 1-¼" high, running the full width of the speaker. I think the new base looks more elegant than the metal feet and seems to offer a sturdier mounting surface.

A Breakthrough in Full-Range Planar Music Reproduction
The previous 20.1s have offered world-class midrange and highs, with world-class bass definition and very good but not world-class midbass punch or slam. Many people, including me, would gladly trade an ill-defined boom box for high-definition planar bass. On the other hand, with a flagship speaker, why should we trade anything? The same question applies to dynamic and horn systems costing upper-five through six figures. At that price, why shouldn’t the speakers do everything? They should, but often they don’t. That is why it is relatively common to see very large and expensive dynamic speakers and horn systems being used with (usually very expensive) subwoofers.

The 20.7s offer substantial improvements over the treble and midrange reproduction of the 20.1s, although I am not sure these improvements qualify as “breakthroughs” as such. They are probably more evolutionary in nature. First, the tweeter seems much better integrated with the midrange driver. In the past, it was not uncommon for the ribbon tweeter to “stand out” on its own with some types of music. For me, this necessitated a loading resistor for the tweeter, balancing the value of the resistor between extended and airy highs, on the one hand, with making sure the tweeter did not call attention to itself, on the other. With the 20.7s I have not encountered this issue. At first I installed the resistors out of habit, believing they would be necessary. But the tweeter sounded smooth and open without calling attention to itself, so I removed the attenuation tweeter and replaced it with a speaker jumper. The highs are now even more open than before, but still the tweeter does not seem to call attention to itself. This improvement in integration is a really nice achievement. The attenuation resistors can always be easily installed, with negligible degradation to the sound, if the user still believes there is a little too much treble output in his or her room.

The ribbon tweeter remains a work of art, easily overlooked when one is confronted with a wide array of competing tweeter technologies. With the right source material, it offers unparalleled delicacy of timbre, laser-like focus into the farthest reaches of the stage, and superb air and atmosphere (if on the recording), all without harshness. Furthermore, it will play loudly enough to fully satisfy on music ranging from full orchestral to heavy metal, without distortion. To be fair, it still won’t play quite as loudly as many dome and horn tweeters. But I play rock and roll at very high levels in my medium/large listening room and have not had an issue with the tweeters of the 20.7s distorting, breaking up, or blowing protection fuses. Moreover, this tweeter seems to be able to retrieve innermost detail on a level with the best electrostats.

The 20.7 midrange driver is, in my view, also state-of-the-art in terms of transparency and tonal accuracy, commensurate with the tweeter. It seems somewhat, not a quantum amount, smoother and more coherent than the 20.1s. As already noted, the transition between midrange and tweeter is now more seamless. In listening to an old favorite, “The Ubiquitous Mr. Lovegrove” from the Dead Can Dance Into the Labyrinth LP (4AD), there is a refrain repeated by the vocalist, “I don’t believe you anymore.” As he lowers his voice at the end of the refrain, on the 20.1s his voice would sound ever so slightly thick and discontinuous. Not so on the 20.7s, where he sounds completely natural throughout. On all material auditioned with the 20.7s, acoustic instruments and voices sound remarkably like acoustic instruments and voices heard live. As Jonathan Valin wrote in his blog, the 20.7s will greatly appeal to those who seek “the absolute sound.” Don’t we all? These speakers are superb at conveying the sound of live acoustic instruments in a real performance environment. The instruments and vocalists are not miniaturized, nor are they enlarged. It is very possible that the more direct dispersion patterns of dynamic and horn speakers could lead to a conclusion that more information is being presented, but that appears to me to be a psychoacoustic effect. The same (or more) information is being presented by the Maggie tweeter and midrange (and bass panel), but its slightly more diffuse overall presentation may lead some to erroneously conclude that some information is missing. It’s not.

I would be remiss if I did not here mention what I believe to be one of the greatest advantages of a large line-source speaker: the size and location of the image in the vertical and horizontal planes. Whether the listener is seated or even standing, the orchestra, soloists, band, or singers are presented dimensionally in a way closer to real life than can be achieved by almost any other speaker design, large or small. There is little to no sense of compression in any dimensional plane. Instruments float in space at ear level, even if you are standing. If the source material and your listening room allow, instruments also float in space to the sides and to the rear of the speakers. Small floorstanders simply cannot offer this degree of realism—all too often it seems like you are listening to a miniaturized orchestra or soloist. In my view, even most large dynamic speakers may not be as convincing as the 20.7s in size and space. All too often the large floorstanding speaker, even flagships costing over $100,000, rely primarily on a single dome tweeter facing the listener, sometimes augmented with a rear-firing tweeter to add “ambience.” To me, it often seems that regardless of how large the dynamic speaker may be, the sound seems “beamed” from wherever the dome tweeter or horn tweeter (or midrange) may be located. (I am preparing for the hate letters.) With its tall line-source tweeter and midrange, the 20.7s do not exhibit this “beaming” effect and seem to offer a more uniform and lifelike presentation of instruments and people in real space, regardless of exactly where you may be seated. I am not saying that seating position is unimportant with the 20.7s—it is. To obtain the best staging laterally, there is still a “sweet spot,” although that spot is wide enough to allow for more than one listener. But regardless of where you sit, the tall line source still seems to place lifelike-sized instruments in a close to lifelike-sized vertical and horizontal space. That is an accomplishment and feature not to be undervalued. 

While on the subject of the soundstage, the 20.7s will exhibit excellent depth so long as there is adequate open space between the speaker and the front wall. Indeed, for the first time the 20.7s even reproduce sounds and ambience behind the listener, but more about that in a minute. As you move the speakers closer to the wall, the sense of depth will compress. Thus, to get the great reproduction of which the 20.7s are capable, the potential buyer must be willing to commit to placing the speakers properly in the room. To anyone considering the purchase of any large speaker system, dynamic or horn or planar, I do not believe this should be a significant issue. All of them need to be placed somewhat into the room to sound their best. To be sure, the 20.7s will sound excellent in smaller rooms and placed closer to the walls, but to realize their full performance potential they need room to breathe. (Magnepan the company, in its written materials and on its website, is careful not to prescribe any specific rules concerning placement of the speakers or associated equipment, although helpful general guidelines are given.) In my experience with the 20 Series, I believe they need to be placed at least four to five feet in front of the front wall. If room permits, a distance of seven to eight feet would be optimal, but not absolutely essential for enjoyment of the 20.7s.

Featured Articles

Lists