Magico A5 loudspeaker
It’s rare for a Stereophile reviewer to review two loudspeakers in a row from the same manufacturer, but then these are unusual times. Because of the pandemic, Magico’s M2s got stuck here for a year (I know: poor me). By the time they were packed up and shipped out, it was time for a long-scheduled review of the less-expensive, more-massive Magico A5 ($24,800/pair).
At $63,600/pair equipped with the no-longer-optional M-Pod footers (footnote 1), the now-departed M2 costs roughly 2.5 times what the newly arrived A5 costs. (The A5 comes with mere spikes.) Like all current Magico speakers, both are sealed-box, acoustic suspension designs, which means that at the bottom end, the response falls off at 12dB/octave—slow enough to have useful output a full octave below where the low bass starts trending down. That’s a much slower rolloff than with the more common bass-reflex (ported) designs.
The A5 is the bigger speaker of the two, with significantly more cabinet volume, which should translate into more and deeper bass—as should the A5’s three 9″ woofers, which, doing the math, have about 2.5 times more woofer surface area than the M2’s two 7″ bass drivers.
Magico is a company that measures and that practices physics-based design based on established psychoacoustic knowledge. But it is also a company that listens; sure, Magico owns a Klippel Near Field Scanner and a laser interferometer, but it also has the second-nicest listening room I’ve visited. Science and listening need not be opposed concepts, even if, regrettably, some people seem to see it that way. Where Magico parts ways with some of the more subjectivist loudspeaker makers is in their belief that a product that measures well should also sound good. But that doesn’t keep them from listening.
While some well-regarded loudspeakers have intentionally (or unintentionally) lively cabinets, a scientific approach to loudspeaker design requires that cabinets be acoustically inert. It’s desirable for a loudspeaker to dissipate some of the resonant energy of the air vibrating inside the cabinet, but the cabinet itself is not the best dissipator, because at least some of the energy absorbed by a cabinet will be released as sound after a time delay; that’s distortion. Absorbing energy is what mineral wool and other cabinet-stuffing material is for. Energy absorbed by those materials is dissipated as heat.
The M2 achieves its cabinet-wall inertness via carbon fiber, which is very stiff and relatively light. Stiffness means it does not absorb vibrational energy readily; low weight means it doesn’t store much energy. (In the M-series speakers, most of the cabinet is carbon fiber, but the top and bottom caps are aluminum.) Carbon fiber makes it expensive and labor-intensive to manufacture and to finish. Apparently, you can buy a giant chunk of aluminum alloy and machine it for much less.
The A5 cabinet is made from the same aircraft-grade, precipitation-hardened aluminum alloy used in Magico’s Q-series speakers. Tempered aluminum alloy is heavier than carbon fiber, but it’s stiff, with an advantageous ratio of stiffness to weight, which helps suppress internal resonance—as does the “complex internal bracing” (quoted from the Magico website) inside.
Aluminum makes some people think lightweight and crinkly, like foil or an aluminum can. But the A5’s aluminum chassis is massive, thick and hard. When I rapped my knuckles against the cabinet to try to detect cabinet resonances, I hurt my knuckles. The only appreciable vibrations I noticed were in my bones. This speaker is 180lb of mostly metal.
The tweeter and the midrange driver are each mounted in their own sealed chamber. Magico’s Alon Wolf told me that the A5’s 5″ driver is the first true, pure midrange driver ever to grace a Magico speaker; apparently, the 6″ drivers used in other Magico speakers extend into the upper bass. (Incidentally, the A5’s 5″ driver comes very close to being 6″.)
Just as science-based designers want stiff enclosures, they also want stiff driver cones, for roughly the same reasons: They want their cones to move in and out, not to flex and vibrate internally. For years—I don’t know how long—Magico has used “Nano-Tech” drivers which coat their cones with graphene. Graphene is a high-tech material that’s lightweight and extraordinarily stiff—so stiff that its Young’s modulus (a measure of stiffness) is hard to measure, but it’s somewhere around 1TPa or about 15 times stiffer than aluminum.
The A5 may be part of Magico’s least-expensive range, but it is, or was, the first Magico speaker to adopt a particular innovation: an “aluminum honeycomb core” in their driver cones. This was planned to be introduced with the flagship M9, but the A5 was ready first so got the nod. All the drivers in the A5 (except the tweeter of course) utilize this new cone construction. It’s exactly what it sounds like. The “honeycomb core” is said to make the A5’s graphene-coated cones even stiffer and lighter, which makes it more likely that they will operate (in their passband) in a purely “pistonic” manner: just moving in and out without vibrating internally. The M9, now that it’s finished, also has this cone technology.
There’s more to a driver than a cone, however: Wolf told me that overall, the M-series drivers are more sophisticated than the drivers on the A5—another reason the M-series speakers cost more.
Very stiff driver cones often come with steep-slope crossovers, because once they start to break up, they do so violently. It’s best, therefore, to operate them strictly in the frequency range where they’re not breaking up. Typically for Magico, the A5 utilizes, on the low-pass side, “elliptical-symmetry” crossover filters, a topology that’s able to achieve very steep rolloff with a low parts count. And because elliptical filters have “zeros,” or “notches”—points where the impedance is effectively infinite—they’re very good, when designed well, at eliminating especially problematic frequency ranges. (I don’t know whether this characteristic is important in Magico’s designs.)
The A5 is also the first Magico speaker—Magico says it’s the first loudspeaker anywhere, and I’ve got no reason to doubt it—to use Mundorf’s new “MResist Ultra” foil resistors. Magico says they offer “greater power handling, transparency and liquidity.” The other crossover parts are also all from Mundorf.
I almost forgot the tweeter: It’s “based on the fundamental design platform and geometry of the M-series tweeters,” but the 28mm beryllium diaphragm lacks the diamond coating, which, in the more expensive speaker, adds additional stiffness but very little weight.
Cheaper than cheese
All that is factual; I should add my personal, subjective take on the A5’s physical package. In size, it’s big but not huge. It is, however, imposing. It emanates gravity—that sense of massiveness—in much the way that Egyptian pyramids do, or Alpine cliff faces (although obviously on a smaller scale). Touch it, spend time around it, and you’re impressed with its substance. Aluminum has famously low heat capacity, yet I swear these speakers took three days to warm up completely after they were brought in off the truck midwinter. (As they warmed up, their sound changed dramatically.)
For all that, though, the metal enclosure is beautifully anodized to a seemingly durable eggshell-sheen finish that’s available—to repeat the Ford Motor Company cliché and frequent Stereophile trope—in any color as long as it’s black. With its nonshiny black paint, the A5 also emanates darkness—and here, to be clear, I am not talking about the sound. Nothing is shiny on this speaker other than the stiletto spikes (which aren’t all that shiny), and there’s a bit of a sheen on the machined tweeter surround. Otherwise, the A5 is a place where photons go to die. Which I like.
Drivers are bolted on, the screws exposed (the better to tighten them if they get loose). There’s a single pair of high-quality binding posts—no provision for biwiring or biamping. If the boxy A5 seems utilitarian, it’s an aesthetic many will appreciate. My wife, who loves nice, natural wood, likes this package, finding it preferable to some shiny wood veneers, which can sometimes look fake even when they’re real.
Footnote 1: Apparently, given a choice, no one bought the M-series speakers without the M-Pods.
Published at Fri, 18 Jun 2021 18:21:00 +0000