BalancedForce 210

Deep, Powerful, and Detailed

BalancedForce 210 delievers powerful bass with electrostatic-like detail to any audio system, whether for high-end stereo music listening or multi-channel home theater. Its two-driver, force-canceling configuration virtually eliminates cabinet resonance and the resulting bass blur that plagues conventional subwoofers, while a sophisticated DSP-based amplifier ensure the purity and accuracy of the sound from the drivers.

$3,499.99 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 for 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 Stealth Series Vanquish and Axis Speakers Reviewed

"The MartinLogan Stealth line of architectural speakers impressed me. Their build and component quality is significantly high. It is obvious that much thought went into the design of these speakers, and the results are ultra high-end. MartinLogan has created a quality product that will provide a proud sense of ownership. When coupled with the BalancedForce 210 subwoofer, the sum performance was greater than any one speaker's individual achievement. I used to avoid my family room... However, thanks to the addition of the Vanquish and Axis speakers, I now find myself wanting to watch movies in the family room. I would highly recommend this product if you are considering an architectural speaker solution for your space"

—Greg Handy, Home Theater Review
Read the full review»

MartinLogan Balanced Force 210 Subwoofer

"I can’t claim that the MartinLogan BalancedForce 210s are the end-alls in low-end reproduction, or that they will fool you into thinking there is an actual standup or electric bass sitting in your living room. What I can say is that they have brought me much closer to the real thing and made me a believer in subwoofing. Now that the 210s are in my listening room, my music–and not just music where bass is prominent–has taken on a new life. They have made a far greater difference in my stereo than any other component I can remember in a very long time. If you have a large room or really feel the need to hear low bass, the BalancedForce 210s are essential tools to getting the most out of your music."

—Spencer Holbert, The Absolute Sound
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

20–120 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 10" (25.4cm) cast-basket, highexcursion, aluminum cone with extended throw driver assembly, sealed non-resonant asymmetrical chamber format


850 watts
(1,700 watts peak)

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: 125 Watts
Idle: 15 Watts


96 lbs. (43.5 kg)


19" x 19.1" x 19.4 "
(48.3cm x 48.6cm x 49.4cm)

Customer Reviews For BalancedForce 210

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  • Saturday, June 16, 2018

This sub is the most amazing sounding sub I have ever heard, the sound matches perfectly with my main speakers ESL11a. It’s a little pricy but worth every penny, you cannot find a better subwoofer to blend with Martin Logan speakers. It’s a must have part of any electrostatic panel speaker. I wish the color match to my ESL11a was better, both are dark cherry and two totally different shades, but the finish is pristine and a very nice component to showcase with other ML speakers, looks defiantly make this sub have the WOW factor.

Glen J.

  • Sunday, May 31, 2015

Seamless extension to the lowest octave of human hearing
I used to work in the field of engineering acoustics, including some work in speaker evaluation using impulse functions. When I saw that Martin Logan was selling some subwoofers that were capable of custom tuning using what appeared to be a familiar technique, I had to have one. The PBK space averaged transfer function that they appear to be using just begged to come home with me. So I bought the BalancedForce 210 and ordered the PBK accessory to be delivered later. I thought this set up would have really excellent "play value" for someone with my interests. It was my plan to mate this subwoofer to my Theos main speakers in a two channel system. I noted that Martin Logan has a custom function that can be downloaded to effect this pairing, and I intend to install the proper file later. I am writing this note today because, following the instructions in the BalancedForce 210's owner's manual, I was able to pair the subwoofer with the Theos beautifully, and without resorting to downloading any files or using the PBK accessory. I will look forward to doing these future tweaks, but for now I am wrapped up in very pleasant listening. The Theos are quite good, have a +/- 3 dB limit at about 43 Hz. The 210 allows you to pick up the next lower octave of program content. Many two channel sources have very little, or even no acoustic content in this lowest audible octave, but for many recordings, the lowest audible octave adds richness and reality to things like large drums, very low bass notes from organs, electric basses, acoustic basses, synthesizers, organs, and the like. I've played through several cds today, and I think there were noticable improvements that I could hear in every case. Most of the musical program material that I selected was chosen for my love of the music. But eventually I had to try some recordings that present special challenges to reproduction equipment. The most notable of these was Paula Cole's "This Fire." I have NEVER before heard a believable playback of the first cut, Tiger. There are a couple of bass segments on this cut that will cause every other speaker, including the unaugmented Theos, to crash and burn. The Theos augmented by the 210 breezed through this cut, including all of the absurd infrasonic bits that accompany the audible low bass notes. I like this subwoofer better than I thought I would. Its low frequency cut off limit is 30 Hz, so this allows it to "get out of the way" of the Theos very effectively, and they mate up exceedingly well. The stock settings of 90 degrees for phase, 0 for the 25 Hz boost/cut setting, 4 for the level setting, and 30 for the low frequency limit setting seem to be hard to improve on. I look forward to being proven wrong when I get around to downloading the Theos matching file, and going through the PBK set up. I would buy this component again without reservations.