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Reviewed by
Howard Kneller


S2/12t Subwoofer

Features SnapShot!


Model: S2/12t

Price: $4200 USD
Dimensions: 31"W x 21"H x 16"D
Weight: 83.5 pounds

Warranty: Five years parts and labor

  • Two 12" aluminum ribbed woofers
  • 500W (manufacturer rated) MOSFET switching amplifier
  • Servo technology
  • Can be used as low-frequency companion to rear speakers
  • Buffered LFE output for daisy-chaining multiple subs

My new home theater was under construction for the past several months. When it was finally completed, I turned to the boxes of gear waiting to be reviewed, and eventually got to the Genesis Advanced Technologies S2/12t subwoofer ($4200). While I’d heard of Genesis, I knew little about the company, and nothing at all about the S2/12t. I grabbed my razor knife and opened the box to take a look at what I thought would be just another subwoofer.

What I discovered was that the S2/12t is not just another subwoofer. Even at first glance, it looked unique. In fact, due to its black color and lack of right angles, the S2/12t looks like something right out of Lockheed-Martin’s Skunk Works program, home of the U2, the SR-71 Blackbird, and the F-117 Stealth Fighter. I was intrigued. Then, rummaging through the user manual, I discovered that the S2/12t had a few unique features that told me it meant serious business. So out of the box it came.

Servo technology and features

A visual inspection of the S2/12t reveals, in addition to its unique appearance, two 12" woofers of ribbed aluminum. According to Genesis, this allows them to be lightweight, yet stiff enough to exhibit no flexure or resonance from 16 to 140Hz, the frequency range within which the S2/12t is designed to operate.

Behind the scenes, the action is in the S2/12t’s servo bass system (the "S" stands for "ServoSub"). This system employs an accelerometer to constantly compare the woofers’ output to the input signal. As needed, a signal is then applied to the woofers to correct any discrepancy. Servo systems are often used in subwoofers because with very-high-impact signals -- from a kick drum, say -- the cone’s momentum can keep it moving even after the signal has stopped. The result can be sonic overhang, bloat, and loss of definition.

According to Genesis, servo systems virtually eliminate woofer distortion. In fact, Genesis states that even at moderate levels, non-servo woofer systems often have distortion levels that exceed 10%. Genesis asserts that its servo system reduces distortion to less than 1% at almost any output level. They also assert that this system drives the woofer at constant acceleration, thus making its response nearly flat within its frequency range.

Servo systems require a lot of current to ensure that the woofers are precisely reproducing the signal. Therefore, they are very demanding of amplifier power. For this reason, class-D switching amps, which are highly efficient and create little heat, are often used in servo systems. The S2/12t uses a discrete MOSFET switching amplifier rated at 500W and with output capability of up to 1kW, thus allowing for high damping and thermal stability at high volumes.

In addition to taxing amplifiers, servo systems typically place a significant burden on transducers, which convert electrical signals into mechanical cone vibration and, hence, sound. The transducers used in servo systems must be robust, yet light enough to quickly and gracefully react to changes in the signal where necessary. According to Genesis, the transducer used in the S2/12t has been carefully developed to strike an uneasy balance between weight and rigidity.

At $4200, the S2/12t is not something you’d recommend to a casual hobbyist. But beyond its big-ticket price, the S2/12t has some unique features that make it clear that only hardcore home-theater and music aficionados need apply.

First, the S2/12t can of course be used to reproduce either the LFE channel in a home theater, or to provide low-frequency extension in a two-channel music system. However, it can also be used in multichannel music systems to provide low-frequency extension for the rear speakers. In fact, through something that Genesis calls LFE Blend technology, the S2/12t will simultaneously reproduce the LFE track and the rear-channel content. Genesis claims that by blending these signals in this manner, you can achieve significantly better bass management.

Second, the S2/12t not only has an LFE input, but an LFE buffered output as well. This allows you to daisy-chain multiple subs through an RCA or XLR cable, and dispenses with the necessity of splitting the LFE signal out of your processor. Genesis recommends pairing the S2/12t with one of its other subwoofer models, each of which will perform best in a different part of your room.


I connected the line-level LFE output on my Integra DHC-9.9 A/V processor to the LFE input on the S2/12t. I then adjusted the bass gain to zero and set the LFE gain to setting 6, which is the halfway position. This would best allow the software in my surround processor to automatically dial in the appropriate LFE level. I set the phase to 0. In order to complement the frequency response of my MartinLogan Vantage speakers (which contain active woofers), I adjusted the low-pass filter to 40Hz. Not having either a 20’-long sub interconnect or similar lengths of speaker cables, I was unable to test the S2/12t’s prowess as a low-frequency complement to my rear speakers.

Prior to positioning the S2/12t in my room, I spoke to Gary Koh, CEO of Genesis. He advised that if I was using only one S2/12t, I shouldn’t place it in a corner. Doing so, he said, would excite every bass mode in the room. Indeed, experience has taught me that in positioning a subwoofer, a corner will generally afford more bass output than placement elsewhere.

Nonetheless, being the know-it-all that I am, and realizing that the acoustics of any room are hard to predict, I at first ignored Koh’s advice and placed the S2/12t in the front left corner of my room -- and discovered that the output from there was indeed too explosive; it sounded boomy at about 50 and 120Hz. Because digital room-correction software can do only so much, I ate humble pie as I crawled around my room with my ears near the floor, eventually deciding to position the S2/12t along the left wall.

A final word on setup: I absolutely love the looks of the S2/12t, and my guess is that you will too. Just be aware that, unless your home is decorated in Late American High-Tech Military Style, with lots of stealthy black-on-black tones, the S2/12t is likely to have a Spouse Acceptance Factor equal to that of a laser-guided missile.


I first tested the S2/12t with the Blu-ray version of Iron Man, in which Robert Downey Jr. plays Tony Stark, a wealthy arms manufacturer, inventor, and playboy who is captured by terrorists after being betrayed by sinister elements within his own company. To escape from the terrorists’ cave, Stark uses spare weapons parts to develop a powered suit of armor that gives him superhuman strength, a full complement of firepower, and the obligatory ability to engage in subsonic flight.

In chapter 11, the S2/12t demonstrated iron-fisted control over the LFE content it was fed. The rumble of Stark’s flight was both muscular and detailed. When he took aim at a weapons depot that had fallen into the hands of the terrorists, the resulting explosions were deep, clean, and visceral, each explosion clearly heard as a separate event. In fact, as a result of the S2/12t’s subterranean reach, I could strongly feel the explosions as well.

In chapter 14, Stark fights a bad guy who, of course, wears his own superpowered suit of armor. Cars are tossed around, buildings crushed, roads pulverized. With the S2/12t on the job, it seemed as if it was all taking place right in my listening room. Amazingly, the S2/12t didn’t break a sweat as it helped to fully dramatize these scenes.

I also tested the S2/12t with the Blu-ray version of The Exorcism of Emily Rose, whose title sums up the main story plot. The meat of the movie occurs during chapters 10 and 11, when the exorcism of this young girl occurs. Without the S2/12t, Emily’s exorcism would undoubtedly be less frightening, as the sub brought home the realism of various scary low-level sounds, including the repeated sharp and violent sounds of lightning that occur during the ritual.

Next up was the Blu-ray Live at Montreaux 2003, from the classic rock band Yes. This disc focuses on Yes’s classic hits, not their later work. Chris Squire’s bass work in chapter 11, "The Fish," is nothing short of a tour de force. Even considering that this is a live recording, the S2/12t rendered Squire’s bass in a refined and natural way. Superb leading attacks and lack of noticeable overhang caused each note to be clearly delineated. The timbre was very convincing, and dynamics were impressive.


I compared the S2/12t to my MartinLogan Descent i servo subwoofer ($3495), which, with similar technology at a similar price, seemed a worthy opponent. The Descent i has three 10" aluminum-cone drivers positioned in a balanced configuration, each powered by its own 250W amplifier, for a combined total output of 750W. Actually, the Descent i has three servo systems, one for each woofer.

Picking a favorite wasn’t easy. At the end of the day, however, the Genesis wasn’t able to play quite as loudly as the MartinLogan -- though it took excessive, even unrealistic volume levels to reach this conclusion. On the other hand, the S2/12t reached ever so slightly deeper than the Descent i. But keep in mind that I’m talking about subtle differences that I wouldn’t have noticed at all if not clued in by the resonating structural weaknesses of my room. Both subs will likely go lower than you’ll be able to hear. With music, the comparison was a proverbial toss-up. The S2/12t and Descent i were both very articulate and, at the end of the day, both offered all-around top-notch performance.


Based solely on its stellar sonic performance, the S2/12t warrants critical recommendation. However, when you also consider its features, versatility, and cutting-edge appearance, it can fairly be said to be among a handful of exceptional subwoofers at its price. The S2/12t may look like something out of a classified military-weapons program, but it should not be kept a secret from serious home-theater buffs and music lovers. Easily recommended.

Review System
Speakers - MartinLogan Vantage (mains), MartinLogan Stage (center), MartinLogan Script i (surrounds), MartinLogan Descent i (subwoofer)
A/V processor - Integra DHC-9.9
Amplifier - Halcro Logic MC50
Sources - Marantz DV9600 DVD player, Denon DVD-2500BTCI Blu-ray player
Power conditioners - Synergistic Research PowerCell SE, PS Audio Noise Harvesters, DIY parallel filter
Cables and power cords - Synergistic Research
Isolation devices - Bright Star Audio Big Rocks and Little Rocks, Black Diamond Racing cones and pucks, DIY amp stands
Room treatments - Synergistic Research Acoustic Art system
Display devices - Epson Home Cinema 6500 UB projector, Stewart Filmscreen Luxus Communicator screen

Manufacturer contact information:

Genesis Advanced Technologies, Inc.
654 S. Lucile Street
Seattle, WA 98108
Phone: (206) 762-8383
Fax: (206) 762-8389

E-mail: info@genesisloudspeakers.com
Website: www.genesisloudspeakers.com

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