BalancedForce 212

Ultimate Bass

Building on the groundbreaking technology of the original Descent, BalancedForce 212 incorporates new features and enhancements that simplify system integration while improving performance. Its signature two-driver, force-canceling configuration virtually eliminates bass-blurring cabinet resonance. And each rugged, custom-built aluminum-cone driver is driven by sophisticated DSP-based, high-power amplifiers. The result is dynamic, unrestrained output to the very lowest frequencies, yet with clarity and definition approaching that of electrostatic transducers.

$4,499.99 each
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Ultimate Performance Subwoofers

Chances are you've read or heard at some time that adding a subwoofer to a system built around electrostatic speakers is nearly impossible. Although that's not necessarily true (and we have the subwoofers to prove it), the idea is grounded in experience. For many years subwoofers and electrostats did not blend very well. Turn on the sub and maybe you got the deeper, stronger bass you were looking for but that wonderful electrostatic snap and midrange clarity were, if not gone, now smeared and disconnected.

Our goal, when we began our first subwoofer project, was to deliver the good stuff — deep, tight, powerful bass — and none of the bad. We wanted to build subwoofers that, when combined with ultra-fast electrostatics or conventional cone speakers, would blend seamlessly to the very bottom of the frequency extreme. BalancedForce subwoofers are the full realization of years of engineering by the MartinLogan team combined with the latest innovations in advanced digital signal processing, amplification, electrical system designs, and room correction.

BalancedForce® Alignment

Opposing Aluminum Element Woofers or Deep, Clean Bass

Dual low-distortion woofers pair a high-power magnet structure with 10- and 12-inch aluminum cone diaphragms to deliver huge excursion and sound output while preserving minute bass details, all without a hint of distortion. The cone material's exceptional damping properties ensure the smooth, non-resonant response necessary for seamless blending with high-resolution full-range loudspeakers.

BalancedForce 212

These woofers, spaced 180 degrees apart in a 'BalancedForce' configuration, operate in exact opposition, to nullify distortion causing cabinet vibrations and deliver pure bass energy. Traditional subwoofer enclosures suffer from an equal and opposite reaction to the cone's movement, generating acoustic vibrations within the cabinet. You feel this by touching the cabinet. Although the "physics" of this phenomenon actually cause a subwoofer cabinet to resonate or even dance, most subwoofer designers apply weight or mass to the cabinet to minimize such disturbances, but still leave one byproduct—"smeared bass". BalancedForce is an elegantly simple solution that removes the variable of cabinet vibration contributions from the acoustic equation.

BalancedForce 212

Amplifier Design

Advanced Ultra-Efficient D-Class Amplifier

BalancedForce subs match powerful proprietary switching amps with incredible woofer drivers resulting in tightly defined bass while keeping distortion at the lowest possible levels. The BalancedForce 210 features an 850-watt class-D switching amplifier capable of a 1700-watt peak operating at over 90% efficiency. BalancedForce 212 features dual 850-watt amplifiers (one for each woofer) with a total system power of 1700-watts (3400-watts system peak).

Low-noise, high-power transformers and switching power supplies feature high-quality MOSFET transistors, noise-suppression networks, and control circuitry to provide tremendous levels of current with extremely low levels of distortion. Split power supply rails minimize distortion while maximizing switching efficiency. Military grade glass epoxy circuit boards, temperature sensors, and protection circuitry guarantee quality sound and reliable trouble-free operation.

PBK Room Correction & 25Hz Level Control

Although correct placement plays a key role in optimizing subwoofer performance, positioning a subwoofer often requires compromises. The optional MartinLogan Perfect Bass Kit (PBK, sold separately) uses a computer and microphone to listen throughout the listening environment and tailor the sub's performance to the unique acoustic properties of a room—resulting in clean, powerful bass down to the lowest frequencies.

Additionally, a built-in 25Hz level control allows listeners to adjust subwoofer output by ±10dB and compensate for excessive room gain by cutting output in the 20- to 30-Hz range, or to accentuate the feeling of deep-bass energy by augmenting those frequencies.

BalancedForce 212
BalancedForce 212

Custom Low-Pass Filters for
Individual Loudspeaker Models

Custom tailored low pass filters are available for nearly every floor standing MartinLogan loudspeaker released in the last 30 years. These optional custom filters adjust the subwoofer's low pass settings to seamlessly blend with the roll-off characteristics of individual loudspeaker models. Filters are easily installed via a user-friendly process involving a USB thumb drive and are available for free download. Many unique filters are currently available and additional filters will be added as new speakers are released.


Beautiful Finishes

High-gloss black cabinets and top trim are standard. Top trim is available in Gloss Black, Black Ash, or custom painted finishes.

BalancedForce 212
BalancedForce 212

Sealed Cabinets

Although ports are a convenient and cost-effective way of increasing low-frequency output, their reliance on resonant energy impairs bass quality. The BalancedForce subwoofer's sealed system exhibits less transient-blurring group delay while maintaining smooth, consistent response, regardless of music or movie source material.

Multiple Input Options

Simultaneous LFE and 2-Channel Connections for Seamless System Integration

Robust connection and control systems allow simultaneous connection of both 2-channel stereo music and multi-channel home theater and allows each source to have individual crossover and level settings, giving listeners a perfect performance in every application. LFE input via RCA or XLR effectively uses no low-pass filter, leaving crossover control to the processor. Left and right RCA, XLR, and speaker level inputs integrate discrete user-adjustable or speaker specific custom-installed audiophile grade low-pass filters allowing different level and crossover points when playing back two channel music.

BalancedForce 212
BalancedForce 212

Top Mounted Controls

Top mounted controls are discretely hidden beneath a smoked glass accent panel allowing easy access to fine tune the subwoofer's settings.

Unlimited Adjustments

Access the top mounted control panel by pushing firmly on the smoked glass panel. You'll find all of your standard subwoofer controls like Level, Low-Pass Filter and Phase, plus some that are unique to MartinLogan.

A unique tone sweep feature assists users in locating areas in listening rooms where troublesome rattles or resonances may occur. A single press of a button allows listeners to initiate a tone sweep from 120–20Hz. If a rattle or resonance occurs in the room a second press of the button holds the current frequency allowing the listener to investigate and identify the source.

An 'On/Auto (Trigger)/Off' switch controls the subwoofer's energy saving feature. The 'On' setting prevents the sub from entering energy saving mode. When set to 'Auto (Trigger)', the sub will turn on when a music signal is detected and off after several minutes without a signal. If a 12-volt trigger is connected, the triggering device will turn the subwoofer on and off.

Further flexibility is afforded by custom energy transfer coupler (ETC™) spikes, which can enhance stability on thick carpets, or create tighter coupling between subwoofer and floor to enhance overall sound quality.

BalancedForce 212


MartinLogan BalancedForce 212 subwoofer

"The BalancedForce 212s are so flexible that I can imagine them—used in almost any room, and with almost any speaker—restoring the tactile impact and low-end reach that other subs usually leave by the door... Whether or not you have MartinLogan speakers to pair them with, I strongly, strongly recommend the BalancedForce 212. It's definitely not a tubby thumper, and no imagination is needed, because nothing is missing. "

—Jon Iverson, Stereophile
Read the full review»

MartinLogan BalancedForce 212 Subwoofer

"The BF212 is one of those rare subwoofers that can be described as essential. It delivers uncompromised bass with clarity, accuracy, and an utter lack of colorations. Once it’s been tuned to a room with ML’s Perfect Bass Kit, there’s a high likelihood that you’ll never need another sub. Never… it is my judgment that the BalancedForce 212 is in a class with the best subs available to the home-audio enthusiast. The BF212 is one for the short list -- it’s required listening for anyone who’s dead serious about the low end. Highly recommended."

—Kevin East, SoundStage! Hi-Fi
Read the full review»


To run Anthem Room Correction (ARC) with your speakers you will need to purchase a PBK or ARC Kit (Please note that MartinLogan Perfect Bass Kit (PBK) microphones are fully compatible with Anthem Room Correction for MartinLogan speakers). Each kit is shipped with a unique microphone.

To download the most up-to-date version of ARC, please click the link below to go directly to Anthem's website.

Get the Latest ARC Software »

System Requirements

ARC Genesis requires an ARC or PBK Microphone, a Mac OS X (10.12+) or Windows (7/8/8.1/10) computer, and an ARC or PBK compatible audio product. One USB port is required. If you are using a laptop computer, check power settings and battery meter before starting to ensure the procedure is not interrupted.


Specifications are subject to change without notice

Frequency Response

18–120 Hz ±3dB; Anechoic through LFE effects input


RCA: 10,000 Ohms
XLR: 15,000 Ohms per phase
Speaker Level: 10,000 Ohms per phase (20,000 Ohms red to black) Compatible with 4, 6, or 8 Ohm rated amplifiers.

Low Frequency Transducer

Two 12" (30.5cm) cast-basket, highexcursion, aluminum cone with extended throw driver assembly, sealed non-resonant asymmetrical chamber format


2 x 850 watts
(3,400 watts peak system total)

Room Correction (Bass Section)

Perfect Bass Kit (PBK) Ready (Sold Separately)

Audio Controls

On, Auto (12V Trigger), Off

Low Pass Filter Frequency

30 - 80Hz


RCA: Left, Right and LFE.
XLR: Left, Right and LFE.
Speaker Level: Left and Right banana jacks.
12V Trigger: 3.5mm
Mini USB (for PBK)
USB (for crossover & firmware updates)

Power Draw

Typical: 250 Watts
Idle: 30 Watts


140 lbs. (63.5 kg)


22.6" x 22.6" x 22.9 "
(57.4cm x 57.4cm x 58.2cm)

Customer Reviews For BalancedForce 212

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  • Wednesday, December 11, 2019



  • Thursday, February 15, 2018

Let me just say straight out that I’m a believer in subs - actually a pair of subs. I know not all will agree. There are good reasons in the past to not incorporate subs but I think now those reasons are moot unless just the thought of having a sub is troublesome which some claim. There has been forever the mystique about full range speakers but very few can really get the job done and besides the ones that do most of us can’t afford anyway. Volumes of air needs to be moved and small cones or multiple thereof just come up short. Also that low end load can put a lot more strain on your amp to drive to the lower frequencies. Having a sub removes a great deal of that load so it can concentrate on 90% of the total sound much much better. Good bass to me is so essential and even though subs only handle the low end they seem to impact the whole sound way beyond its rather narrow frequency range. Good non-boomy bass is essential to the listening experience – period! In comparison bad bass can do the exact opposite probably even make the listening experience much worse than great bass improves. However as good as subs are today the troublesome issues as the ‘no sub for me crowd will tell you’ – better integration with the main speakers and room interactions are big problems left unresolved satisfactorly and they are right. This is exactly what the 212 does so well and so much more! I’ve had my 212’s for a few years now and they continue to amaze me in performance, looks and integration. I’m using these with a pair of CLX Art speakers and am very happy with how they round out the very bottom octave or so. I previously had a pair of Descent i’s with Summit X’s that I liked very much. However room placement was limited and I could never quite get comfortable with the bass produced in that room. There were plenty of adjustments on the Descent and Summit X’s but those adjustments came up short in my opinion. I blame it all on my room as since then I have moved them to a larger multi-channel room and they are performing very nice indeed. Since my choices for placement are very limited in the music room I needed a sub that could produce good bass where I put them. I can’t say enough about the PBK kit and the software that does exactly that and more. It’s quite easy to perform and you get to see on a graph just how a room is beforehand and the near perfect correction the software calculates – it’s just amazing! Combine this with the custom crossover that is available for most if not all ML speakers there now is some serious sonic improvements happening indeed! I’m familiar with the Descent i design with 3 cones and was a little troubled with the new 2 cone design. It seemed to me the design of the 3 cone was very well thought out so I was concerned with the change and why. Let me say that now that I have experienced the new design it is definitely an improvement at a very basic level. One thing that they did keep from the older design were the controls on top – smart and very convenient. So when you add it all up the much better integration of the sub to your room using the PBK kit, the custom crossover for the main speakers and the basic design improvements this is a real big step up on sub technology! Sub doubters beware you may have met your match!

Roger E.

  • Sunday, January 18, 2015

Essential addition for large spaces, build quality is first rate
I have a pair of 212s teamed with Martin Logan Summit Xs to fill an open concept house with sound and the 212s are a key component to creating a unbeatable audio experience. After much research I concluded that my subwoofers needed to be precisely matched to my electrostatics, and the 212s were the answer. I have the 212s placed on the other side of the house from the Summit Xs but you would never know it as the lower frequencies appear to be coming from the Summit Xs. The 212s are not inexpensive, but the build quality and audio rewards are top notch, and it is a product that will last you for a few decades.