Cambridge Audio Minx S325 5.1-Channel Speaker System (TPV 102)
Small satellite/subwoofer-type speaker systems are nothing new and quite frankly they all promise “big sound from small boxes.” Given that some extremely formidable VBC’s (ery ig ompanies—e.g., Bose, Sony, and others) offer well-established sat/sub-type products through big-box retailers and factory outlet stores across the country, it seems fair to ask if the world really needs yet another speaker system of this type? But give Cambridge Audio’s new Minx system a careful listen and I think you might answer that question with an immediate and resounding “Yes!”
This review focuses on Cambridge Audio’s S325 system ($1399), which is a bundled 5.1-channel system that consists of five Minx Min 20 satellite speakers (the larger of Cambridge Audio’s two Minx satellite designs) and a 300-watt Minx X300 subwoofer (the middle model in the Minx subwoofer lineup). What exactly sets the Minx system apart? The answer, in a nutshell, is that the Minx rig fulfills the promise of “big sound from small boxes” far more completely—and with substantially more subtlety and nuance—than competing sat/sub systems in its price class have ever been able to do.
Just to give you a sense for the full scope of the Minx product family, let me point out that the smallest 2.1-channel Minx system, the S212 system, starts at about $549 while the largest 5.1-channel rig in the group, the Minx S525 system, sells for around $1799. But from the smallest package to the largest, the appeal of Cambridge Audio’s Minx packages centers on sonic sophistication, pure and simple. Though undeniably “budget-priced,” Minx systems simply do not sound like typical low-cost speaker packages usually do; in truth, they offer what we regard as benchmark performance in their size and price class, which means prospective buyers can expect to get more (actually, a lot more) than their money’s worth. Below, I’ll point out key highlights that set the Minx system apart from its competitors.
FEATURES & TECHNICAL HIGHLIGHTS
Not unlike a certain nationwide pizza chain, which proclaims that “better ingredients” make its product superior, all Cambridge Audio Minx systems incorporate a special, signature ingredient said to make a huge difference in performance. That ingredient is the so-called BMR (Balanced Mode Radiator) driver Cambridge uses in each and every one of its Minx satellite speakers. To be candid, it would take an article longer than this entire review to give a thorough explanation of the technology and benefits of BMR drivers, so let me instead provide a brief summary here along with links to several AVguide.com blogs that discuss BMR technology.
About BMR Drivers
Most of the drivers used in typical loudspeakers feature rigid and relatively non-resonant diaphragms (think “domes” in tweeters or “cones” as used in woofers or midrange drivers) that are designed to behave like nearly perfect “pistons.” The drivers respond to audio signals by moving inward and outward (ideally with minimal distortion), thus creating the sound waves we hear. There are several key “rules of the road” for piston-type drivers that are worth bearing in mind. First, the diameter of a driver diaphragm must be smaller than the wavelength of the highest frequencies the driver is meant to reproduce, if the driver is to disperse well (thus promoting good imaging). Second, the lower a driver goes, the greater the volume of air it must displace in order to play at a given loudness level. Together, these two rules help explain why woofers (which handle bass frequencies) are larger than midrange drivers, and midrange drivers are in turn larger than tweeters (which handle the highest frequencies).
One further point to note is that, whenever loudspeakers assign various bands of audio frequencies to different drivers, an electrical “crossover network” typically must be used to direct those frequencies to their appropriate drive units (high frequencies routed to tweeters, midrange frequencies routed to midrange drivers, and so on). Much though designers struggle to make sure that crossover networks are low in distortion, the fact is that they do inject some coloration that affect the overall purity of the sounds we hear.
BMR drivers, on the other hand, behave very differently than traditional piston drivers do, and in ways that are frankly a bit difficult (at least for me) to picture in the “mind’s eye.” Here’s the deal:
•Rather than being shaped like “domes” or “cones,” all of the BMR drivers I have seen to date feature diaphragms that look like flat paper or cardboard disks.
•At the lowest end of their intended operating ranges, BMR drivers behave like traditional piston-type drivers (that is, the drivers pump inward and outward, producing sound waves).
•But, as frequencies climb higher and higher, the entire motion of the BMR driver changes in a radical way, transitioning from “pistonic motion” to a so-called “ripple motion” where—instead of moving inward and outward like a piston—the entire surface of the disc-shaped diaphragm begins to ripple, with waves of motion spreading from the center of the disc outward toward its rim (almost like the concentric ripples you would see on the surface of a pond if you threw a pebble in).
•One very desirable property of the BMR driver’s distinctive ripple motion is that it offers inherently excellent dispersion. In practice, this means you can typically get away with using a single BMR driver to serve as both a midrange driver and as a tweeter—and without need for a crossover network.
Until now, I have only seen BMR drivers used in relatively expensive high-end loudspeakers, such as the Naim Audio Ovator-series loudspeakers from England. But now, the Cambridge Audio Minx system makes BMR technology available at (by far) the lowest price point we have seen thus far.
Blogs Discussing Speakers Featuring BMR drivers
•My blog entitled, “RMAF (Rocky Mountain Audio Fest) 2009, Day One: Loudspeakers Under $20k” (click here). This blog discusses multiple loudspeakers, including Naim Audio’s Ovator S-600 loudspeaker ($10, 450/pair), which was arguably the first hi-fi product to use a BMR driver.
•“The Absolute Sound at RMAF 2010: Neil Gader on Electronics Under $20k and Loudspeakers under $20k” (click here). This blog discusses multiple loudspeakers, including the BMR driver-equipped Naim Audio Ovator S-400 loudspeaker ($5250/pair).
•My blog entitled, “Radical BMR Drivers Make Cambridge Audio’s Minx System Different & Better” (click here). This blog provides an expanded discussion of BMR driver technology.
Highlights: Minx Min 20 Satellite Speaker
•Dual 2.25-inch BMR driver housed in compact enclosures.
•If described in conventional loudspeaker parlance, the Min 20 would probably be called a “1 ½-way” loudspeaker. In practice this means the Min 20’s dual BMR drivers together handle frequencies from about 130Hz up to around 800-900Hz, at which point a simple “low pass filter” rolls off output from the lower of the BMR drivers while the upper BMR driver is allowed to run all the way up to 20kHz—crossover free!
•Precision molded enclosures finished in gloss black or white.
•Extremely compact dimensions (6-inch x 3.1-inch x 3.3-inch).
•Banana jack-type speaker terminals adapt easily to various types of speaker wires.
•Rear of enclosure has recessed fitting that can accommodate wall mount brackets (included) or optional tabletop or floor stands.
•Snap-on speaker grilles with logos suitable for vertical (standard) or horizontal (optional) positioning. One horizontal-logo grille is included with the S325 system package to allow one Min 20 to be positioned on its side for center channel use.
Highlights: Minx X300 Powered Subwoofer
•Forward-firing, 8-inch woofer driver.
•Downward-firing, 8-inch passive radiator.
•300-watt, DSP-controlled, digital amplifier.
•Subwoofer controls: volume, phase (continuously adjustable, 0 – 180 degrees), crossover frequency—complete with markings to show ideal settings for use in systems with Min 20 or Min 10 satellite speakers, main power switch, separate on/off mode switch with an “always on” setting or an “automatic signal-sensing” setting.
•Subwoofer inputs/outputs: wireless input port, stereo analog audio inputs via RCA jacks (left input jack labeled as LFE input for use with AVRs), stereo analog audio outputs via RCA jacks.
•Enclosure styled and finished to complement the Min 20 satellites.
Caveat Emptor: The Minx System Needs (lots of) Break-In
Before I say one word about the sonic character of the Minx system I first need to caution readers that this system absolutely, positively needs a good bit of break-in before it starts to sound decent, let alone good. Straight from the carton the Minx system sounds almost painfully edgy, constricted, and “tightly wound,” meaning that at first, highs and upper midrange frequencies sound rough, tizzy, and strained, while bass seems thin, anemic, and poorly controlled. But be patient, give the system some playing time, and think of every story you’ve ever heard about ugly caterpillars turning into beautiful butterflies. Better sound comes to those who wait.
Our review sample of the Minx system began its sonic turnaround after it accumulated about 10 hours of playing time, made more sonic strides once it got to about 15 hours of total time, and continued to show improvements until its sound seemed fully “fleshed out” after about 20-30 hours of total time. What about the sound changes during this break-in period? First, highs become progressively smoother and better defined, as do upper midrange frequencies—as a result of which both imaging and soundstaging markedly improve. Down below, bass becomes at once more ample and better defined, and the blend between the sub and the satellites gradually becomes smoother and better integrated. You might think that what I am describing are small, incremental improvements, but they aren’t. In truth, these changes are so substantial that they make for a night/day improvement in the Minx system’s overall sound. For this reason let me offer one hint: if you use a calibration system during initial set-up, go back and re-run the calibration after the system has been played for 30 hours or so.
Once ready to give of its best, the Minx system exhibits three signature qualities that will favorably impress most listeners—even those who might normally not consider buying systems of this type (because they presume they’ll need something larger and more costly).
Refinement and Finesse
From the midrange on up, the Minx satellites sound markedly more refined, detailed, subtle, and delicate than you would expect a system of this size/price to sound. Many small systems sound, well, small—as if their satellites are continually straining and struggling to do their jobs. As a result, most small sat/sub systems exhibit glaring sonic errors, such as a tendency to blur details, smear or distort instrumental and vocal timbres, exaggerate the edges of transients sound to a painful degree, or make highs and upper midrange frequencies sound “papery” and thin. The Minx system, however, sounds nothing like this. On the contrary, it sounds open, clear, quite well detailed, and shows a certain richness and purity of tonal color that is almost unheard of in this price range. High-frequency percussion instruments, which can be a real pain as heard through typical tiny sat/sub rigs, sound terrific through the Minx system.
Disappearing Act Imaging, Spacious Soundstaging
Once they are fully broken-in the Minx satellites seem almost to “disappear” in a sonic sense, meaning that they draw little if any attention to themselves and instead create the illusion that the sounds of instruments, voices, and cinematic sound effects are originating from specific points within a large three-dimensional soundstage. I attribute these qualities to the remarkably broad, smooth dispersion patterns that Cambridge Audio’s BMR drivers are able to achieve. As you listen to the Minx system at play, then, you may be struck by two qualities of the sounds you are hearing. First, sounds don’t seem to cling to or even to originate from the tiny Minx Min 20 satellites, which makes it easy to suspend disbelief and to happily “go with the flow” of the music or movie soundtrack you’re playing. Second, the overall size, scope, and seamlessness of the soundstages you’ll experience seems almost impossibly large and spacious given the diminutive size of the Minx system components, themselves (the experience is more like what you would expect to hear with a bigger, more costly mid-size system in play). It’s in this specific area that the Minx system really delivers on the promise of “big sound from small boxes.”
Surprisingly Robust Dynamics
Cambridge Audio has, I think, really done its homework in the DSP programming for the X300 powered subwoofer, which—please bear in mind—also handles frequencies up to (and, of course, a bit beyond) 130Hz. As the system plays, you’ll hear a decent attempt at low bass (though the woofer doesn’t really reach down below the mid-30Hz region), ample mid-bass, and very good handling of upper bass/lower midrange frequencies. But the really significant part is the sheer graciousness and, yes, joyful punchiness with which this little sub tackles large-scale dynamic swells and low frequency effects of the type that give many small systems conniption fits. Does the Minx rig play as loudly as well-made mid-size and full-size surround speaker systems? No. But does it sound more robust, lively, and at-ease with itself than other small sat/sub systems we’ve heard. Yes, and by a not-subtle margin.
I was curious to see how the Minx system would handle the demands of a full-scale action film and so I tried the system while watching the action-packed thriller Salt. One scene that proved revealing in many different senses involved the state funeral for a U.S, Vice President, where first U.S. President Lewis (Hunt Block) and then Russian Federation President Matveyev (Olek Krupa) rise to deliver eulogies (both unaware that a daring attack is unfolding beneath the floors of the cathedral where the funeral is held).
Listen carefully to the sound of President Lewis’ voice as he addresses the crowd and note how his voice reverberates within the cathedral interior. Through the Minx system, the echoes and reverberations sound almost uncannily and eerily realistic, so that the sound of a lone voice speaking within a huge, open space becomes thoroughly convincing. In my case, in fact, it seemed as if the dimensions of my listening room had magically expanded, while the acoustics of the room shifted from those of a normal family room to take on the characteristics of a large, stone walled cathedral with high, buttressed ceilings.
But in the spaces below the cathedral, agent Evelyn Salt (Angelina Jolie) is mounting an attack on the Russian President that will soon shatter the solemnity of the occasion overhead. We hear the terse, fierce sounds of hand-to-hand combat as Salt fights her way through teams of Secret Service agents guarding the lower floors, and then the violent, percussive sound of Salt creating a distraction as she shoots out the control panel for the cathedral’s pipe organ, unleashing a cacophonous eruption of low pipe organ notes. Finally, Salt plants and then triggers an explosive charge that causes the floor beneath the speaker’s podium to collapse, dropping the chagrined Russian President into the basement below, where Salt methodically shoots him. I frankly expected the Minx system to wilt during this barrage of gunshots and explosions, but it did not. Instead, it maintained a truly remarkable degree of composure while conveying an unexpectedly lively and powerful presentation of the effects at hand. The really cool part is that the sub’s DSP circuitry managed to control the woofer’s output levels so artfully that I wasn’t particularly aware of any “throttling” or compression being applied (although the effects were sufficiently loud and aggressive that I must presume the DSP circuits intervened to prevent the woofer from bottoming out).
To check out the Minx systems capabilities in terms of reproducing high-resolution multichannel music recordings, I put on a favorite bellwether track: “Country Roads” from Gary Burton’s Like Minds [Concord, multichannel SACD]. I have mentioned this recording in many TPV reviews, and part of what I like about it is the fact that it offers a distinctive “onstage perspective” of a great jazz performance. By design, you should have the illusion of standing onstage in the midst of the musicians, and through the Minx system that’s precisely what you get. But what you might not expect, at least not from a system the size of the Minx rig, is the unusually vivid, vibrant, and large-scale presentation that the diminutive S325 system delivers.
Through the Minx system, Gary Burton’s vibraphone seems to be bursting at the seams with rich tonal colors, while each of Burton’s adroit mallet strikes seems to launch a veritable fountain of transient energy that soars upward and outward, filling the recording space. Similarly, when guitarist Pat Metheny takes his solo, the honey-toned voice of his guitar sounds at once relaxed and yet also intensely focused, even though it is presented far off to the right hand side of the stage. More so than many music recordings, “Country Roads” captures moments where listeners can—and through the Minx system do—hear instruments performing almost directly beside them, not just in front of them as in most typical audiophile recordings. It is greatly to the Minx system’s credit that it creates smooth, wraparound images and a wonderfully realistic and enveloping soundstage, in much the same way that larger and more costly systems do.
But if “Country Roads” shows us the Minx systems imaging and soundstaging strengths, it also reveals one minor weakness, which is a subtle (actually, very subtle) sense of discontinuity that arises between the upper end of the X300 subwoofer’s range and the lower end of the Min 20 satellite’s range. What exposes the discontinuity is bassist Dave Holland’s exquisite solo, which neatly spans the transition region between the sub and the satellites. It isn’t so much a case of textural differences between the sub and satellites, per se (though there is probably a bit of that), but more a case where you become aware that the imaging characteristics of the sub are, after all, different from those of the satellites. As musical lines progress upwards from the sub’s range to the satellites’ range, sounds at first seem anchored to the subwoofer enclosure, but then expand into a heightened sense of three-dimensionality as the satellites take over the workload. In fairness, though, readers should note that this is an area where virtually all of the small sat/sub systems I’ve heard (this one included) exhibit minor sonic shortcomings.
Finally, I put on a track from a classic two-channel audiophile recording— “Take Five” from The Dave Brubeck Quartet’s Time Out [Columbia, stereo SACD]—just to see how the Minx system would fare. Not too surprisingly, the Minx rig passed this test with flying colors, doing a lovely job with Brubeck’s syncopated, swinging 5/4 rhythmic figures on the piano, and offering a surprising sophisticated rendition of Paul Desmond’s gorgeous and evocative alto sax solo. While the timbral qualities I observed weren’t quite on a par with those I might have heard from, say, today’s best $2000 – $3000/pair floorstanding speakers, they were downright amazing given that the Minx S325 package is a full-on 5.1-channel surround system selling for a tick under $1400. But my favorite part of the experience involved listening (several times in a row, actually) to Joe Morello’s wonderful drum solo, which serves as the living pulse that drives “Take Five” forward. Morello’s playing is so sure-handed and effortless that it makes the very uncommon 5/4 time signature sound like the most natural thing in the world (but just you try and play it as smoothly as Morello does). The taut skin sounds of Morello’s drums resonating within the recording space sounded simply terrific through the Minx rig, demonstrating that this system is every bit as comfortable with stereo recordings as it is with multichannel material.
Consider this system if: you want an extremely compact speaker system that produces huge, spacious soundstages, offers levels of sonic finesse that far exceed the norms for speaker packages in its class, and that sounds dynamically punchy and robust—even when answering the demands of vigorous action film soundtracks or when playing relatively loudly in large living room spaces, etc.
Look further if: you need King Kong-grade dynamic capabilities or the want the heightened resolution, detail and focus you might expect from today’s better $3000-and-above systems. Also look further if you are extremely finicky about sound quality in the tricky transition region between the upper bass and the lower midrange (where you might hear some minor discontinuities between the Minx sub and satellites).
Ratings (compared to comparably-priced surround speaker systems):
Transparency and Focus: 9
Imaging and Soundstaging: 10
Tonal Balance: 8.5
Bass Extension: 9
Bass Pitch Definition: 9
Bass Dynamics: 9.5
Let me come right out and say it; at this moment in time, Cambridge Audio’s Minx system has earned the unofficial title of “King of the Compact Surround Systems”—at least with respect to any of the competing alternatives I’ve heard thus far. As far as I’m concerned, it has earned this title through its combination of unexpectedly high levels of refinement and finesse, stouthearted dynamics, exceptionally vivid imaging, and spacious soundstaging—all offered at a more than reasonable price.
SPECS & PRICING
Cambridge Audio Minx Min 20 Satellite Speaker
Driver complement: Two 2.25-inch BMR drivers. Drivers share the workload from 130Hz to ~800-900Hz; above that point output from the lower BMR driver rolls off, while the upper BMR driver continues upward to 20 kHz, crossover free.
Frequency response: 130Hz – 20 kHz
Sensitivity: 87 dB
Impedance: 8 ohms
Dimensions (HxWxD): 6” x 3.1” x 3.3”
Weight: 1.65 lbs. each
Warranty: Not specified
Cambridge Audio Minx X300 Powered Subwoofer
Driver complement: One 8-inch forward-firing woofer, one 8-inch downward-firing passive radiator
Integrated amplifier power: 300 watts
Frequency response: 33Hz – 200Hz
Dimensions (HxWxD): 12.4” x 10.5” x 11”
Weight: 16.5 lbs. each
Warranty: Not specified
Price: $599.99 each
System Price: $1399 as tested
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