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.
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.
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.
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.
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
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.
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.
High-gloss black cabinets and top trim are standard. Top trim is available
in a variety of optional high-gloss, hardwood, and real-wood veneer
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
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.
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.
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
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
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"
"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."
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
(1,700 watts peak)
Room Correction (Bass Section)
Perfect Bass Kit (PBK) Ready (Sold Separately)
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)
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)
Specifications are subject to change without notice
PBK Software + Calibration File
Each Perfect Bass Kit is shipped with a unique microphone. Please input the serial number found on your microphone to download the most recent version of PBK along with your microphone's unique calibration file:
The serial number is a six-digit number starting with "5", located on the bottom of the microphone
PLEASE NOTE: PBK software is for use with ONLY BalancedForce or Dynamo products. If you are setting up Masterpiece speakers, you will need use Anthem Room Correction (ARC) software, found here.
Troubleshooting & Support
The Perfect Bass Kit (PBK) is for use with any MartinLogan® subwoofer with a PBK Interface to correct the effects of room boundaries on sound quality. PBK uses proprietary processing to compute the subwoofer's in-room frequency response and then computes a target frequency response for the subwoofer to yield optimal in-room sound. PBK can be used with up to four MartinLogan subwoofers. The frequency response of each PBK microphone is measured precisely and this data is used to create the microphone's calibration file included on the PBK software disk. The microphone can ONLY be used with the matching individual calibration file.
PBK requires a PC running Windows 10, Windows 8, Windows 7, Windows Vista or Windows XP (with Service Pack 2 or 3). If you are running a newer operating system than mentioned see info about updating the PBK files in the owner's manual. PBK is currently not compatible with Apple Macintosh computers.
TWO USB ports are required.
If you are using a laptop computer, check power settings and battery meter before starting to ensure the procedure will not be interrupted.
Although systems vary, in general, if your home theater receiver/processor also has a Room Correction system, PBK should be set up and running before setting up your system's 'EQ', especially if more than one PBK subwoofer will be in use.
1) PBK Microphone Recognition
2) PBK, Computer, and Operating System Compatibility
3) MartinLogan PBK and Paradigm PBK Are Not Interchangeable
4) PBK and other Room Correction Technologies
1. PBK Microphone Recognition: We have received several reports relating to PBK microphone setup/driver installation. The microphone occasionally fails to install the first time it is plugged into a computer. When the microphone is plugged in allow approximately 1-minute for the computer to automatically install the microphone drivers. If installation fails try the following:
a. Unplug the microphone and reattach it to the computer.
b. Connect the PBK and subwoofer USB cables to an external USB hub and then connect the USB hub to the computer.
2. PBK, Computer, and Operating System Compatibility: We recommend running MartinLogan PBK on Windows 10, Windows 8, Windows 7, Windows Vista or Windows XP (with Service Pack 2 or 3). PBK is currently not compatible with Apple Macintosh computers.
3. MartinLogan PBK and Paradigm PBK Are Not Interchangeable: The PBK systems (hardware and software) from MartinLogan and Paradigm Electronics are not interchangeable. MartinLogan PBK software contains specific information about MartinLogan subwoofers. Additionally, the drivers installed on the computer are brand specific and not interchangeable.
4. PBK and other Room Correction Technologies: MartinLogan's PBK™ (Perfect Bass Kit) is designed to adjust performance of specific MartinLogan subwoofers to reduce room induced bass anomalies. PBK is not a replacement for other room correction systems that are designed to optimize multi-channel audio systems. When beginning the task of optimizing an audio system's performance, the first step should always be proper setup of the front, center, and surround speakers. Proper setup of these speakers requires proper positioning, toe in, and (if available) adjusting other built-in controls. The next step should be running PBK to adjust the subwoofer's output to account for room interactions. After running PBK, the subwoofer's performance and integration with the main speakers should be optimized by adjusting the subwoofer's level, phase, low-pass filters, and other controls. Only after proper setup of speakers and subwoofer(s), including running PBK on the subwoofer(s), is it time to run your processor's full-range room correction system to enhance overall system performance within the room.
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.
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.