Introduction to the M&K Sound X12 Subwoofer

Best of 2014 Awards

While most people have never owned M&K Sound speakers, almost everyone has heard them. M&K speakers are used extensively throughout the movie industry to master, mix, and edit sound. If you have ever seen Wall-E, King Kong, Lord of the Rings trilogy, Black Hawk Down, Pirates of the Caribbean, Iron Man, or the new Star Wars trilogy, you have heard the sound of M&K. In fact, I can think of no other speaker manufacturer who has won so many Academy Awards for sound; the afore mentioned films are but a fraction of M&K’s rather lengthy list of Academy Award wins and nominations. Since inventing the world’s first balanced dual-drive subwoofer back in 1973 for Steely Dan’s Pretzel Logic and introducing the world to the first in-home subwoofer in 1974, M&K Sound has steadily gained the respect of the professional sound and recording industry.

The innovation continued at M&K Sound, and they introduced the world’s first powered subwoofer in 1977. The masterminds at M&K Sound have continued to be at the forefront of subwoofer innovation and their newest subwoofers, the “X” series, promises to best all others.

The new “X” line of M&K Sound subwoofers consists of three models: the X8, X10, and X12. When asked how the new “X” line subwoofers were different from the previous generation, Claus Glaesner, President of M&K Sound USA, replied, “These subwoofers are a major step up in every way from our previous subwoofers. The build quality, driver quality, and sound quality represent a new reference level of subwoofer that was previously not available on the market.”

As their names suggest, they utilize two 8″, 10″, or 12″ drivers, respectively. The dual driver design allows the X series M&K Sound subs to move massive amounts of air while minimizing any distortion created by the individual cones.

The X8 is pending THX certification at the time of writing this review, and the X10 is THX Select2, while the X12 is THX Ultra 2 certified. The THX Select X10 is rated with a flat anechoic response to 35 Hz, while the larger THX Ultra 2 certified X12 is rated with flat anechoic response to 20 Hz, and the in-room response significantly lower. How can it get any better than reviewing one of M&K Sound’s newest flagship subwoofers? Easy, you review two!


  • Design: Dual Driver, Sealed Enclosure
  • Certification: THX Ultra2
  • Driver: Dual 12″ Drivers Arranged in Push-Pull Configuration
  • Amplifier: 400 Watt RMS (700 Watt peak), Class D
  • Frequency Response: 20 Hz – 200 Hz ± 3 dB
  • THD+N: <0.5%, @ 400 Watts Amplifier Output
  • Inputs: 2 Balanced XLR and 2 Unbalanced RCA
  • Outputs: 2 Balanced XLR and 2 Unbalanced RCA
  • Dimensions: 26″ H x 17.3″ W x 18.1″ D
  • Weight: 79.3 Pounds
  • MSRP: $3,200 USD
  • M&K Sound
  • SECRETS Tags: M&K, Subwoofers, Push Pull


The Design of the M&K Sound X12 Subwoofer

“There is no replacement for displacement.” This mantra resonates (pun fully intended) throughout the sports car world, but is equally applicable to the subwoofer world. Because all speakers, at the most basic level, are glorified air pumps, it makes sense that you could move more air with a bigger driver.

Unfortunately bigger drivers flex more than a smaller driver made of the same material by simple virtue of having more area to flex. This “flex” or “give” results in some level of distortion. The M&K Sound X12 overcomes this by utilizing two 12″ drivers. The two 12″ drivers have the same cone area as one 18″ driver and can thus move the same amount of air, but without the negative impact and increased distortion on sound. Another happy side effect is a smaller footprint and thus smaller negative impact on the SAF (Spouse Acceptance Factor) that would result from the larger enclosure required to house said driver.

It is worth examining the construction of the M&K Sound X12 subwoofer in detail, as it utilizes a somewhat unconventional driver arrangement.

The two drivers are mounted with the front driver facing forward out of the enclosure and the bottom driver facing upward into the enclosure. When sound is coming from the subwoofer, both drivers move in the same direction, i.e., into the enclosure or out of the enclosure, so that one driver is pushing and the other is pulling.

Because the two drivers are identical, but one is moving toward the front of the driver and the other is movng toward the back end of the driver at any one instant in the music, even-ordered harmonics are reduced.

The enclosure itself is made of heavy, 2.2 cm thick MDF with significant internal bracing to ensure tight tolerances in distortion. The 12″ drivers on the X12 are held at attention via a 400 Watt RMS (700 Watt peak) class D amplifier, ensuring enough “oomph” to faithfully reproduce the loudest of bomb blasts.


Setup of the M&K Sound X12 Subwoofer

Weighing in at almost 80 pounds, and being 26″ high, the M&K Sound X12 subwoofer is not a small beast. After a very enlightening discussion with Claus Glaesner, I was able to procure two of these rather intimidating subs for my review. He believes, as I do, a home theater should have at least two subwoofers, the second preferably along the opposite wall from the first. After maneuvering these rather Spartan-esque boxes into place along the right front and left rear wall, I set out to dial them in to my room.

At first glance (and second and third) the backside of the M&K Sound X12 is a bit intimidating. There are more selectable/usable controls on the M&K Sound X12 than any other speaker I have dealt with. In addition to the usual two RCA inputs, there are two balanced inputs. There are also two RCA outputs and two balanced outputs for optional pass through. The phase selector is a continuous knob from 0-1800 rather than the usual 00 – 1800 rocker switch. There are three low-pass crossover point options. The first is a fixed crossover point which would be used if the rest of your speaker system were comprised of M&K Sound professional monitors, as these all have their internal crossovers set to 80 Hz to match. The second position on the switch is continuously variable, which then leads over to an adjacent dial with crossover points selectable from 50 Hz to 125 Hz. The last position on the switch is “No Low-Pass THX Mode” crossover, recommended if you use your surround processer’s room correction software such as “Audyssey” for bass management.

There is an input level control with selectable continuously variable dial (-3 dB to +3 dB) or fixed THX specified level. If your receiver or pre/pro is THX certified, you should use the “THX Fixed” setting, as the component will supply the sub with input gain to match the overall system volume adjustment. On top of all this, there is a selectable bass equalizer with either THX specified processing for movies which utilize bass reproduction according to THX standards of 20 Hz at -6 dB, or anechoic M&K EQ (no) processing, which the manual suggests is ideal for smaller listening spaces. While I am generally in favor of giving the consumer more control, even I found the selectable combinations somewhat confusing.


The M&K Sound X12 Subwoofer In Use

Matrix Reloaded: One of the generally more impressive bass scenes on video is in the early part of the movie when the Nebuchadnezzar is returning to Zion. We see massive gears turning to open Zion’s monolithic gates welcoming the Nebuchadnezzar home. The effects editor knew what this was supposed to sound and feel like, and went so far as to actually shake the picture ever so slightly during the gates motion to give the viewer a sense of the shear mass that was being moved. While this scene is always a great one, it was not believable until the two M&K Sound X12 subwoofers were in place. As the gates closed, there was a shockwave I felt for the first time. The X12 faithfully reproduced not only the initial door closing sound but also the residual echo it caused to resonate throughout Zion. The low-end extension of the X12 is astounding! The reproduction was so real I thought for an instant I had just sealed myself in my theater room for good! After the gates close, the Nebuchadnezzar lands at port. I have never really thought this image was necessary, but as it touched down, it sounded like a tanker ship had just run aground in my listening room!

The Dark Knight: One of my new favorite sound scenes is the tunnel chase scene from this movie. There are enough diesel engines, shotgun blasts, explosions, and car crashes to keep even the most bass hungry satisfied. The scene opens with a point blank shotgun blast combined with a low tympani beat at the trail off of the blast for transition into the next shot. The depth of sound and realism conveyed by the two X12 subwoofers was so believable, I felt compelled to check myself for wounds. I had previously not given much thought to the sound as the garbage truck is rear-ending the SWAT vehicle; it always sounded good, but like two cars hitting each other. With the dueling X12 subs in full effect, you get the impression the dump truck is full of trash (and weight), and the SWAT has only people inside (mostly hollow). The metal on metal sound produced by the M&K X12 gave a scary realism to the impact and conveyed the size and texture of the trucks involved better than any subwoofer I have heard.

Just after the Tumbler finishes pushing the garbage truck all the way down the tunnel, it turns and takes off after the Joker. Two sounds struck me here. The first is the deep rumble of the Tumbler’s sizable tires on the pavement as it takes off. The sound is almost too low to hear, but the massive drivers on the M&K Sound X12 makes sure you feel it! The second is the otherworldly, guttural growl the engine makes as it takes off, as if it was just belched out of the netherworld.

At the end of this sequence the Joker’s empty tractor-trailer gets flipped end over end and lands flatly on it’s back with the camera looking straight down the empty trailer. Now, a small trailer sounds different than a large one, a full different than empty, etc. The sound produced from the X12 is scary! The sound was so accurate and fast I could hear the difference between the initial smack of the trailer on pavement, the buckling of the walls, and the final echo of the crash off the walls of the adjacent buildings. These subs bring you into the movie, so instead of watching a trailer flip in a movie, you believe you are actually standing in a street watching the trailer flip in front of you.

The Phantom of the Opera soundtrack: I have loved The Phantom of the Opera since I was a kid, and have seen it performed live many times. The Super Audio CD recording is one of the best dynamic recordings I have heard in a long time and does the live performance justice. I chose to listen in two-channel mode and made adjustments in my pre/pro to include the M&K behemoths in the audio below the crossover point. The thunderous organ of the “Overture” is in full force here, and the X12 handled it magnificently! This score really tests the deep limits of any speaker system with organ notes in the 8-10 Hz range. The M&K Sound X12 subwoofer faithfully reproduced them with aplomb. These are notes you may not even know are supposed to be there unless you have heard the “Overture” played on a true pipe organ as there are few subs that can extend that low and shake your chest. These are sounds you really feel rather than hear.


Conclusions about the M&K Sound X12 Subwoofer

In talking with other home theater owners, I found relatively little time was spent selecting the subwoofer as compared to the other components. While it is not uncommon for a listener to read about and audition speakers for months while deciding on what best fits their listening style, it is uncommon to spend nearly as much effort in selecting a subwoofer. In most cases, the sub simply came with the other speakers as a package or was what the dealer recommended but was not truly auditioned. That is a shame really; as I count these subs among the best, if not the best, I have ever heard.

True to their goal of accurate, dynamic sound reproduction, the folks at M&K Sound have hit a home run with the X12 subwoofer. These subs have excellent frequency response that dives well below the 20 Hz THX standard, down into the depths of the inaudible range and still have impressively little distortion. As impressive as that is on it’s own, these subs have a musicality to them with an accurate, fast response that breathes life into background sounds such as the low roar of a crowd in a stadium, and makes soundtracks and music more dynamic and involving. These subs are at once incredibly fast and accurate as well as able to produce a pulse capable of restarting your heart.

The difference between my home theater subwoofer and the M&K Sound X12 was not subtle. These subs took my theater room from “Wow! That’s better than the movies!” to silent, awestruck faces in the listening room. I have never heard a sub that transformed the experience from simply watching a movie, to believing the movie. I give the M&K Sound X12 subwoofers my highest recommendation, and plan on purchasing one of the review units. Now if only I could convince my wife I need two of them.