M&K Sound X12 THX Subwoofer

Build Quality
PRICE $3,200

Powerful, deep, and taut bass response
Outstanding build quality
Sealed push-pull design
No built-in parametric equalizer

M&K Sound calls the X12 the subwoofer, and I can’t disagree with them. This is one of the best subwoofers I’ve ever heard in my room.

M&K Sound got started when Walter Becker of Steely Dan commissioned Ken Kreisel to design a studio reference subwoofer and monitoring system for the Pretzel Logic mixing sessions. Partnering with a high-end audio dealer, Jonas Miller, Kreisel developed a revolutionary subwoofer that led to the creation of M&K. As time passed, word of mouth spread throughout the music and movie industries, and M&K would go on to create systems for leading studios and in-home installations for producers, actors, and recording artists.

In 1976, M&K launched their first satellite/subwoofer system. The following year, they introduced the Volkswoofer, the first popular sub with a built-in, dedicated power amplifier. Talk about a game changer!

The legacy of M&K grew to epic proportions with the launch of the groundbreaking Dolby Digital surround format. Several movie studios—including 20th Century Fox, Warner Bros., Disney, and Lucasfilm—are said to have installed M&K speakers for their daily audio production work. Unfortunately, M&K fell on hard times and in 2007 filed for Chapter 7 bankruptcy due to what Kreisel called “flagrant counterfeiting of M&K products.” But the brand would live on, as Danish investors bought the assets of the company and some of the former employees became a part of a new company, MK Sound, to continue building on the legacy of Miller and Kreisel. In 2013, MK Sound adopted the earlier M&K moniker.

For the past 11 years, I’ve used a trio of M&K S-150 speakers across the front channels and four SS-150 Tripole surround speakers in my 7.1 setup. However, I failed to consult with my attorney before signing a contract with my wife, which restricted me to one new subwoofer for the next 10 years, so I was stuck with an SVS PC-Ultra that I’d bought in late 2003. Luckily, the contract has now expired, and when Sound & Vision Editor-in-Chief Rob Sabin informed me that I would get to review M&K Sound’s new X12 THX subwoofer, I knew the upgrade bug would attack soon.

A Solid Middleweight
The X12 isn’t the heaviest subwoofer I’ve had in my system over the past few years, but it isn’t a lightweight either at nearly 80 pounds. It’s relatively compact at 17.3 inches wide, 26 high, and only 18.1 deep, and it houses two custom-designed 12-inch woofers tailored to M&K Sound specifications to meet the company’s high performance standards.

The woofers are arranged in a push-pull driver configuration in order to cancel harmonic distortion and, according to the company, adding the second driver provides an additional 6 decibels of usable output. This design also allows for a smaller cabinet footprint, which may make it easier to integrate with your room décor. Indeed, the first comment my wife made about the sub was that it looked better than the “cat scratching post” I currently use, a reference to my cylindrical, cloth-covered SVS. That sure sounds like an opening for an upgrade!

The X12’s build quality is magnificent and comes with a black satin finish. M&K assembles the cabinet from 22-mm-thick MDF with extensive internal bracing to minimize vibration. The sub is powered by a Class D 400-watt amplifier (700 watts peak) and has a variety of input/output choices, including balanced and unbalanced connections with a passthrough option to add more subs. There are three selections for low-pass filters (Fixed 80 Hz, Variable, and No low pass), a phase control variable from 0 to 180 degrees, and two EQ filters (THX and MK EQ). In my room, the Fixed 80 Hz and THX EQ settings provided the best results.

The X12 arrived double-boxed, in order to handle the rigors of ground shipping. (I’d hate to see what it would cost to air-freight this beast.) I’ve found that the best way to save your back is to open the top of the outer box, gently flip the whole thing over, and lift each box off the sub (versus trying to lift 80 pounds out of a box). Befitting the sub’s beautiful finish, M&K Sound includes a pair of white gloves so you don’t put any fingerprints on your new toy. You also get a detachable power cord, a well-written 18-page manual, and two options for feet: screw-in rubber or carpet spikes.

I first set up the sub manually, using test tones from a disc, and ran it that way for about a week. I then performed a calibration with my Marantz AV8801 pre/pro’s built-in Audyssey MultEQ XT32 software. Of the two methods, I preferred the latter because I like what it does to the surround stage, especially during action scenes. But the sub performed flawlessly either way.

The X12 doesn’t include a parametric equalizer (P-EQ), unlike many other subs in this price class (and even some cheaper ones). For some buyers, this may be a turnoff, but I’ve found that most automatic calibration routines built into modern pre/pros and AVRs work quite well.

In Use
I lived with the X12 for nearly two weeks before I really put it to the test, for a couple of reasons. First, I wanted to let the woofers break in as much as possible because I’ve found that some subs don’t show their true colors until they’ve had some hours on them. Second, I wanted to let my ears adjust to the sound of the X12 with everyday listening, to do some day-to-day tuning with a range of program material and make sure I had it dialed in properly.


MTV just named Lorde’s “Royals” as their Song of the Year, and it’s hard to argue with them. The young lady was 15 when she wrote the song, and its bass track seems to be made for testing subwoofers and seeing how well the thump integrates with her sultry voice. In this particular case, the THX-certified X12 and my S-150 studio monitors were a match made in heaven. The bass was tight, clean, and intense, and the frequency transition to my studio monitors was seamless. Lorde may be the queen bee in her fantasy, but if she can keep writing songs with this type of groove and meaningful lyrics, we’ll be hearing a lot more from her in the future.

The Wolverine is the latest addition to the X-Men series of movies, and while the story is more entertaining than I thought it would be, the DTS-HD Master Audio 7.1 soundtrack is the true star of the show. The surround activity is a panoramic masterpiece, and the LFE will certainly wake the dead in every cemetery in town. When the atomic bomb detonates over Nagasaki, you expect to hear a loud boom, but it’s conspicuously absent. There’s a slight moment of silence and then a low-frequency rumble, which, as it moved through my room, shook the hair on my legs before I actually heard the explosion. Later in the film, there are numerous storms, and at one point I thought the thunder giants from The Hobbit were waging a battle in my room. Now that’s impressive. The X12 delivers in spades.

I’m pretty smitten with the X12 and have thoroughly enjoyed my time with it. M&K calls the X12 the subwoofer, and I can’t disagree with them. It goes deep for movies and is controlled and tuneful with music—everything you ask for in a subwoofer. At $3,200, it’s on the costly side, especially when you can buy two subs for a similar price from some Internet-direct companies. Those subs might give the X12 a run for its money, but they may not come with THX’s Ultra2 certification or M&K’s pedigree. Still, despite its steep price, this is one of the best subwoofers I’ve ever heard in my room, and usually I’d be awfully sad to ship it off to the lab for testing. Fortunately, it’s got a round-trip ticket, as I’m hoping to review M&K’s new S-300 series satellites, the upgraded product offering to my S-150/SS-150 combination, and I’ll need the matching sub. Excellent—it’ll give me more time to make the case for that subwoofer upgrade. Highly recommended.

M&K Sound
(855) 657-6863

hk2000's picture

First let me just say that this subwoofer may well be great, but this review reeks of author bias and preconception. the fact that the reviewer is a devout owner of the companies products and came in with all intentions of praising the product regardless what the facts may turn out to be IMO makes it impossible not to take this review with a gain of salt or even a spoonful. I think S&V should preclude any Owner and FAN of a manufacturer products from reviewing said products- especially when the review is totally subjective. How is this subwoofer with a total of 700 watts (Peak) is the equal of 2 SVS SB13 subs (for example, based on a statement in the review)with a total of 3600 watts EACH. Don't even try to justify this review it's just a disgrace.

Subzero1's picture

I agree with hk2000 and would like to see the return of reviews that compare the product being reviewed against other comparable manufacturers products, especially factors such as cost, amp power, MDF thickness,warranty,etc.. I also am considering the SVS PB13 ported sub (2 total) and/or the sealed SB13, both of which would cost substantially less than the $6,400 2 X12's would cost. I'm sure the X12 is a great performer, but are any differences that would be noted in a blind A/B comparison tests going to be so much greater, to then warrant the additional cost of 2 X12's? This is the type of review criteria that reviewers frequently included in the past but is lacking in equipment reviews today. Purchasing 2 X12's for $6,400 would be justified. If the dollar / performance factor simply blew away the lower cost for either the SVS PB13 13 or smaller sealed SB13 13. If not the case in actual listening comparisons, then the much greater cost for the X12 is not worth it IMO.

David Vaughn's picture
For starters, I had no preconceived bias coming into this review. I own M&K speakers, but have never owned one of its subwoofers. Second, the company is different than the speakers I own, since it went through bankruptcy. I state clearly in the review that the sub is expensive and that you could buy two subs from an Internet direct company for the same price of one X12. "How is this subwoofer with a total of 700 watts (Peak) is the equal of 2 SVS SB13 subs (for example, based on a statement in the review)with a total of 3600 watts EACH. Don't even try to justify this review it's just a disgrace." Please show me where I said this in the review? I never made this comparison. Furthermore, comparing only "watts of power" isn't the way to judge a subwoofer. The push/pull design of this sub is extremely efficient. Hear one for yourself before you make a judgement. I've owned an SVS Ultra sub for over 10 years and LOVE it, but this sub has a distinct sound and it moves a ton of air. As I state in the review, it literally moved the hair on my legs (and the sub was 10 feet away from my listening position).
hk2000's picture

Thanks for replying, below you'll find where I got my impressions:

"But the brand would live on, as Danish investors bought the assets of the company and some of the former employees became a part of a new company, MK Sound, to continue building on the legacy of Miller and Kreisel."
That's another way of saying the company- or brand, at least in your mind is still the same. It's human nature, I've always been biased towards NHT, they've changed ownership many times but my bias lives on.
"you can buy two subs for a similar price from some Internet-direct companies. Those subs might give the X12 a run for its money, but they may not come with THX’s Ultra2 certification or M&K’s pedigree."
If that's not saying the X12 would equal the 2 subs or at least it'd be too close to call, then one of us needs to go back to grammar school.

Again, the X12 maybe extraordinary, and you're right I have not listened to it, but I stand by my objections to this review.

David Vaughn's picture
I clearly state that you can get two subs from an Internet direct company that "may" give you the same performance, but without testing said subs versus the M&K directly, I can't unequivocally say that they will equal or surpass the M&K, hence the word "may." For the record, I also just reviewed 2 SVS subs for an upcoming issue (both got Top Picks as well)...so am I biased towards SVS too because I own a SVS sub? Frankly, at one time or another I've owned many manufacturers products, so if I can't review anything I've ever owned or currently own, good luck finding any reviews out there. You ask the impossible.
prerich45's picture

I must come to the reviewers defense on this one. He never mentioned which internet direct companies subs would give the M&K a run for the money (and that's actually a plus he gave for ID companies) and he's also right about M&K's pedigree - Disney,Lucas Films, THX Ultra certification. FYI, I'm not an M&K fan but I've heard them and enjoy them. I also enjoy SVS,HSU, and a host of other subwoofers.
HK2000 ....you read into the text what wasn't there. Don't worry - a lot of people do this ;)

David Vaughn's picture
Thanks for the comment and support and for supporting the magazine and website. Have a great day!
prerich45's picture

No thanks needed - you have in-depth, personal experience with the line, and most people that have been in HT since the late 80's know that Velodyne and M&K ruled the subwoofer world early on. I believe your review sounds par for the course concerning M&K.

Rob Sabin's picture
Given the hard work we do testing products and editing and vetting the reviews, I'm always a little surprised to see the blatant attacks sometimes launched by readers with little or nothing to go on. "Absolute Bias." Wow -- strong words, and I don't see any justification for them in this review. Because the guy owns and loves the same company's full-range speakers? Two points to make here: First, we specifically asked David to review this sub because it's the bottom end anchor of M&K's just-released (and very pricey) S300 system, which I knew he would also be reviewing for us later. He is, in fact, the perfect reviewer for that nearly $18,000 system. He's intimately familiar with what is a very distinct and unvarnished M&K sound (common to studio monitors) from his S150 reference system, and, critically, because of his reference he was the best person on the staff to delineate how much (if any) additional value might accrue when stepping up from the S150 to the S300. The idea that he would have given the sub a positive review if it didn't perform or not call it out for being expensive is utterly ridiculous, and he suggested clearly that there is the potential to get similar performance out of a less expensive subwoofer. But...and this is a big BUT...if you've never heard one of these classic-design M&K dual-woofer push-pull subs, you really are in no position to comment. They are special. And I would add that subwoofer amp power or box size are unreliable indicators of how a subwoofer will perform. Building a really good sub is hard to do, even if you commit the resources in parts.

Which brings me to point number 2: Short of entering into a well-executed double-blind test, there is no subjective audition of any A/V product that is conducted by any reviewer anywhere in which there is no preconceived bias before the review begins. All of his or her prior experience with the brand and with competitive brands, what he or she may have read about the product online or in marketing materials, the price point, even the packaging and the experience of unpacking and setting up the product before the audition begins creates an expectation and mood prior to the listening or viewing. With our limited reviewing resources, we're already biased to select products we hope or expect will perform well--this M&K sub was one of them. But that doesn't mean our reviewers don't call it like they hear it or see it, and that their personal sense of dollar value and their ears (or eyes) don't win out in the end. We know consumers count on us to tell the truth and explain our biases and personal preferences up front to put the reviews in context. Manufacturers also count on us to get it right -- we know we could potentially destroy the sales of a product, and it's my responsibility as editor to make sure we're accurate and conduct our tests fairly and with technical prowess. Reviewing products is a serious business, and all of us take that responsibility very seriously.