Note: Measurements taken in the anechoic chamber at Canada's National Research Council can be found through this link.

Although to most people the name of Polymer Audio Research will be new, the company isn’t. Based in Florida, Polymer began in 2006 with a single loudspeaker, the Logic. Since then, the Logic has been replaced by the Logic MKII. The large and very expensive Master, just released, retails for $130,000 USD per pair, and forthcoming is the Sub subwoofer. The subject of this review is the MKS.

The $42,000 demanded for a pair of MKSes seems a big ask from a company not well known even among audiophiles; in fact, it would be a big ask from even a brand that is a household name. But when you experience the MKS firsthand and hear how it sounds, then see how it’s made and what it’s made of, you might find it surprisingly easy to justify the price. Diamond drivers, anyone?

Description

The MKS is a three-way, four-driver design with two 6.5” Scan-Speak woofers modified by Polymer (the dustcap certainly looks unique), their output augmented by a large port (about 4” in diameter) on the cabinet’s rear. Above the woofers are a 2” midrange driver and a 0.8” tweeter, both made by Accuton, with inverted-dome diaphragms of diamond. Diamond is favored by certain companies -- notably Bowers & Wilkins, who use it in the tweeters of their upper-end models -- because its extreme strength and stiffness help it maintain its shape over a wide frequency band. A diamond tweeter can extend as far as 60kHz without resonances, whereas with aluminum it’s hard to get past 20kHz, and even beryllium tops out at about 40kHz. Diamond’s downsides are its expense and its density; the latter can compromise a tweeter’s sensitivity.

The cost of diamond is reflected in the high retail price of the MKS’s drivers -- the tweeter alone will set you back $2900 each. I couldn’t find the midrange driver for sale in the US, but its retail price in Europe would put the US price well past ten grand apiece. Obviously, Polymer Audio Research doesn’t pay those prices -- they’re a manufacturer -- but these Accuton drivers are some of the most expensive you can buy off the shelf, and make the MKS’s high price a lot more understandable. In fact, it’s easy to imagine the speaker costing even more, given the profit margins typical of other companies. I’ve seen the same Accuton diamond tweeter used elsewhere, in speakers costing even more, though the diamond midrange was new to me -- but if another company is using it, I’ll bet that speaker costs a lot more than the MKS.

But outrageously expensive drivers can’t guarantee a great -- or even a good -- loudspeaker. How those drivers are made to work together is what’s crucial, as is the cabinet they’re housed in.

Talking to one of Polymer’s owners, Daniel Khesin, I learned that the MKS’s woofers and midrange are crossed over below 1kHz, which he concedes is a little lower than some designers would do; he does it to use the midrange as low in frequency as possible to get the maximum benefit of its diamond diaphragm. Khesin also said that the tweeter and midrange are crossed over to each other in the 2kHz range, which was confirmed by the measurements we took of the MKS in the anechoic chamber of Canada’s National Research Council.

Khesin told me that both crossovers have fourth-order (24dB/octave) electroacoustic slopes (electroacoustic refers to a combination of the electrical properties of the crossover network and the natural acoustic rolloff of the drivers), and that each crossover is filled with a damping material and potted to better isolate it. He also said that “all of the inductors in the crossover go through a casting process where each winding is filled with a liquid damping compound and then baked, forming a rock-solid structure.” The MKS’s steep crossover slopes, combined with the low crossover points for the woofer-to-midrange and midrange-to-tweeter handoffs, should guarantee good frequency-response consistency on and off axis, which is important for proper tonal balance and soundstaging.

Should you buy a pair of MKSes, you won’t need to worry about whether or not the grilles will have an adverse effect on the sound -- there are no grilles. (The diaphragm of each diamond driver is protected by a metal mesh that even the smallest fingers won’t be able to poke through.) Polymer’s specifications promise a frequency response of 32Hz-60kHz, +/-3dB; a sensitivity of 88dB/W/m; and a nominal impedance of 4 ohms.

While the diamond-diaphragm drivers are as intriguing as they are costly, it was the MKS’s metal-based cabinet that I found most interesting. It’s one of the most visually attractive I’ve seen in the upper reaches of the high end, partly for its relatively compact size -- not huge, it won’t dominate a room -- but mainly for its overall proportions (41.25”H x 9”W x 16.25”D) and finishing touches. I liked the slender front baffle with the bevels that widen toward the top, and the Merino wool inlaid around the tweeter and midrange -- both touches look nice, while helping to reduce diffraction. I also liked the super-sturdy outrigger feet, which look great while giving the speaker an incredibly firm stance. And I admired the top-quality binding posts near the bottom of the rear panel, which look about as good as binding posts can while permitting tight speaker-cable connections.

While these days I usually criticize speakers with visible screws and bolts -- hiding them looks much better -- Polymer has done a better-than-average job of making such fasteners look good. The bolts securing the drivers are fairly small and black, and so not very visible. Same with the bolts on the side panels. The bolts through the top plate are deeply recessed, which looks decent -- the bolt heads aren’t readily visible, and the holes form a pattern around the deeply engraved Polymer Audio Research logo.

I also liked the MKS’s color combination. The matte-silver top and bottom panels and port contrast wonderfully with the matte-black front, rear, and sides. Although my review samples had already seen some action and were a little beat up, they looked great in my room -- I can only assume that a pair of pristine MKSes would look spectacular. The MKS has the rugged, masculine look of metal construction, but is also elegant in how it’s shaped, colored, and finished.

About all that metal -- as good as it looks, it’s there mostly for the sound. The multiple panels and pieces used for the walls, braces, port, and other parts, made of aluminum and other metals, combine to create not only the heaviest speaker that’s ever entered my room -- each MKS weighs 270 pounds -- but also the one that feels the most dense and inert: as solid as concrete. Polymer makes such a cabinet for the same reason that Magico does for their S5 ($29,400-$32,500/pair, depending on finish, and 190 pounds), which I reviewed last December: to ensure that the sources of the sound are the drivers, not the enclosure.

Sound

When he sent the MKS review samples, Daniel Khesin didn’t tell me much about how to set them up; he was more concerned with what kind of amp I’d use. Although he gave me free rein to try pretty much any sort of amp, including tubed models (he says he’s found VAC amps to work well), he did want me to at least try the most powerful solid-state amps I had on hand. When I told him I had Simaudio’s Moon Evolution 870A ($20,000), which puts out 600Wpc into 4 ohms, he was pleased. He was even happier when I told him I also had on hand a pair of Anthem Statement M1 monos ($7000/pair), each capable of 2000W into 4 ohms. His concern wasn’t so much the wattage, though that would certainly help -- the MKS is only moderately sensitive -- but for control of the bass. Intrigued, I used the MKSes with both amps, as well as with the much smaller Ayre Acoustics VX-5 ($8000, 350Wpc into 4 ohms).

Khesin was right to be concerned -- I quickly learned that the MKS is one bass-strong speaker. It didn’t just go deep -- to easily below 30Hz in my room -- it sounded full through to the upper bass. In fact, it sounded so full that the Ayre VX-5, while sounding acceptable overall, didn’t control the Polymer’s woofers as well as they needed to be -- the bass was rich, but somewhat fat and slow. The VX-5 also seemed to give up a bit when I cranked the volume way high -- it clipped, which indicated to me that the MKS actually is only moderately sensitive, and needs serious juice to be played loud. Enter the Simaudio 870A and the Anthem M1s. The bass still sounded very full, but was now tighter and much better controlled, and power was never an issue -- I could get neither of the new amps to clip, even when I played the Polymers at levels far beyond normal. The speakers never compressed or distorted -- or broke.

But the right amps still weren’t enough to manage all that bass -- where and how the MKS speakers were positioned mattered tremendously. It’s possible that the MKSes’ bass output will be too much for some rooms, particularly smaller ones. The Magico S5s are ultra-tight throughout the entire bass region but a bit light in the upper bass, which caused me to push them closer to the walls than normal to get some reinforcement, in order to produce the kind of heft I wanted. But the MKSes were so strong in the bass that they had to be kept far away from all walls. A bass voicing halfway between those of these two speakers would probably be ideal for the average room.

Luckily, my room is pretty big, so I was able to get the Polymers to work very well even with really bass-heavy music, such as Daft Punk’s Random Access Memories (24-bit/88.2kHz FLAC, Columbia/HDtracks). Polymer seems to have sacrificed some tightness for fullness in the MKS’s bass -- it sounded a little underdamped. For example, even with the Simaudio and Anthem amps, the bass was tighter than with the Ayre -- but not ultra-tight, as were the Magico S5s with the same three amps. In fact, the S5s sounded tighter with the Ayre than the MKSes did with the Simaudio or the Anthems.

The upside to Polymer’s voicing was that all that bass weight helped make the MKSes sound full, rich, bold, and quite a bit bigger than they actually are. “Mining for Gold,” from the Cowboy Junkies’ The Trinity Session (16/44.1 FLAC, RCA), thundered in my room without clouding the midrange, sounding nothing short of glorious. The title track of Sade’s Soldier of Love (16/44.1 FLAC, Epic) had the kind of weight usually heard only from speakers twice the MKS’s size. “Get Lucky,” from Random Access Memories, was projected with a deep, strong bass beat that engulfed the speaker end of my listening room and reached around to envelop me. In my listening notes, in big letters, are the words DEEP, FULL, and BIG.

Overall, the MKS’s strong bass worked exceptionally well in my room -- huge sound, in terms of both bass depth and spaciousness, from a fairly compact floorstander -- but the pièce de résistance was its performance above the bass range.

The MKS’s midrange was a touch laid-back in proportion to the low end, yet superbly smooth, and with just enough presence. In fact, the way the Polymer reproduced voices was nothing short of a revelation. Sade Adu’s gorgeous voice sounded silky-smooth, utterly pure, and completely authentic in “Long Hard Road,” from Soldier of Love. The speakers also projected a soundstage that was truly holographic, hung almost tangibly in space between the two speakers with real presence and stark specificity. I’ve heard this recording many, many times, but this was the best I’d ever heard Sade’s voice -- or this song.

What sounded even better -- astounding, in fact -- were Petra Magoni and Ferruccio Spinetti on the duo’s self-titled debut, Musica Nuda (16/44.1 FLAC, BHM). The pronounced bass of the MKS made Spinetti’s double bass a bit more prominent than usual, but that extra oomph helped create a sense of spaciousness and warmth in my room that was very realistic. Then there was the MKS’s ability to combine clarity and purity in the midrange and highs with equal doses of transparency and detail without sacrificing a thing. Breathy details and subtle inflections in Magoni’s singing were extremely easy to hear, yet the sound was conveyed with utter purity and complete ease. Rarely have I heard a speaker with such high degrees of resolution and musicality.

Magoni’s and Spinetti’s positions on the soundstage were also made completely clear, as was the space around them, which extended way, way out there. The Polymers easily let me hear all the details that my fantastic upstream components and cables can provide. The soundstage of Ennio Morricone’s choral-based score for the film The Mission (16/44.1 FLAC, Virgin), a recording I’ve used to assess soundstaging abilities for as long as I’ve been reviewing, had as much width and depth as I’ve ever experienced in my room. Ani DiFranco’s voice in “Everest,” from her Up Up Up Up Up Up (16/44.1 FLAC, Righteous Babe), another recording I’ve used for eons, had razor-sharp focus with rock-solid specificity -- I could “see” her position on the stage, accurately pinpointed on the lateral and depth axes. In short, the MKSes could cast a stage as wide and open as the best speakers I’ve heard, and place images on it more accurately than almost all of them.

The MKS maintained its superb balance of clarity, purity, transparency, and detail all the way through the highest frequencies -- they were super-smooth and infinitely clean. But in the extreme highs, way up there, the MKS sounded exceptionally clean but a little soft; i.e., slightly reticent or restrained. This was all the more apparent when I compared the MKS to the Magico S5 and the Aurelia XO Cerica ($7100/pair), both of which have tweeters that soar into the upper reaches without reticence or restraint, but tend toward the bright and splashy with recordings that lean that way, and/or if the room is highly reflective.

Like its bass fullness, the MKS’s slight softness in the highest highs had pros and cons. On the upside, the speaker never sounded off-puttingly aggressive, even with bright recordings -- I can’t imagine bright- or edgy-sounding electronics or recordings ever pushing it over the line, nor can I imagine a highly reflective room being a problem. The downside is that those who favor a lively, spirited top end might find the MKS too polite; they’d probably be better served by a speaker voiced like the Magico S5 or the Aurelia XO Cerica. Whichever voicing is ultimately appropriate for you is something only you can decide.

Conclusions

The construction of the Polymer Audio Research MKS is outstanding, its styling is excellent, and its parts quality is remarkable, given the price. Then there’s the sound -- distinctive compared to most other speakers I’ve heard, and in some areas better. In particular, I was smitten by the clarity, purity, transparency, and detail throughout the midrange and highs -- miraculously, all were of the highest order, with not a single one getting shortchanged. This made voices sound astonishingly good in my room, and leads me to think that diamonds might be the audiophile’s best friend. Then there are the MKS’s other strengths, such as the awesome size and scope of the soundstage and the precision of imaging, the latter ranking better than almost all I’ve heard, and only a hair short of the finest. The MKS’s unique sound made it thoroughly enjoyable to listen to, and makes it stand tall among the best speakers out there.

One concern remains: the MKS’s bass. It extends incredibly deep, making this compact floorstander sound at least twice its size, and likely contributes to the vast sense of spaciousness the review samples could provide in my room. But it’s pronounced. If you consider buying a pair, be sure to use an amplifier that can fully control the Polymer’s woofers, and make doubly sure that your room can accommodate the prodigious low-frequency output a pair of MKSes is capable of. My amps and room were good matches for the Polymers -- what I heard didn’t merely impress me, it pushed many of my audiophile hot buttons and positively thrilled me.

That’s why I can recommend the Polymer MKS to anyone who can afford to spend $42,000 for a pair of speakers, is willing to take a chance on a lesser-known brand, and is searching for its unique type of construction, appearance, and, of course, sound. The MKS is the kind of speaker that can make a little-known company very well known. Very quickly.

. . . Doug Schneider
das@soundstagenetwork.com

Associated Equipment

• Loudspeakers -- Magico S5, Revel Ultima Salon2, Aurelia XO Cerica
• Amplifiers -- Simaudio Moon Evolution 870A, Ayre Acoustics VX-5, Anthem Statement M1s (monos)
• Preamplifiers -- EMM Labs PRE2, Simaudio Moon Evolution 740P
• Digital-to-analog converters -- Meitner Audio MA-1, EMM Labs DAC2X
• Computer -- Samsung laptop running Windows 7 and JRiver Media Center 18
• Digital interconnect -- AudioQuest Carbon
• Analog interconnects -- Crystal Cable CrystalConnect Standard Diamond
• Speaker cables -- Siltech Classic Anniversary 330L

Polymer Audio Research MKS Loudspeakers
Price: $42,000 USD per pair.
Warranty: Five years parts and labor.

Polymer Audio Research
1601 Green Road
Deerfield Beach, FL 33064
Phone: (305) 420-6703

Website: www.polymeraudio.com