Custom Filters & Firmware Updates

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Installing a Custom EQ Filter:

To add a custom low-pass filter to your BalancedForce subwoofer:

  1. Download the appropriate zipped file to match your main speakers.
  2. Unzip and save the custom low-pass file in the root directory of a USB flash drive (a USB flash drive was included with your new subwoofer, but any flash drive 32GB or smaller should work)
  3. Insert the flash drive into the USB Input on the back of the subwoofer. The subwoofer will automatically find the file and load the custom low-pass filter.

To assure a successful upload to your subwoofer we recommend having no other files or folders on the flash drive—the subwoofer can only load one file at a time. Please review your subwoofer's manual for more information.

Why do some BalancedForce custom filters have multiple options?

One of the benefits of adding a subwoofer to a speaker system is to relieve your main speakers from having to play low bass. It has long been a common practice for MartinLogan to provide a bass control on our floorstanding speakers. Some early MartinLogan speakers adjusted bass by minus 3dB. More recent models with PoweredForce woofers allow adjustments of plus or minus 10dB.

The woofer sections of MartinLogan speakers are equalized to extend the bass response of their low frequency drivers. This equalization causes power from your external amplifier to be delivered to the woofers. Turning the bass control on the speaker to minus 3dB or minus 10dB (and letting the subwoofer fill in) relieves the load on your external amplifier, delivers more power for the upper bass and midrange, and allows the speakers to play louder. MartinLogan BalancedForce custom filters allow you to experiment and determine which method works best for you—letting the speakers play low bass to their fullest capability or letting the external subwoofer fill in. There is no right answer regarding which option to use. As always, we recommend that you try both options and trust your ears.

ModelFilter File (click to download)Additional Description
AeonAeon(i).zipAeon / Aeon i filter
Aeon iAeon(i).zipAeon / Aeon i filter
AeriusAerius(i).zipAerius / Aerius i filter
Aerius iAerius(i).zipAerius / Aeruis i filter
AscentAscent(i) -3dB.zipAscent / Ascent i filter (with bass control set at -3dB)
AscentAscent(i).zipAscent / Ascent i filter (with bass control set at flat)
Ascent iAscent(i) -3dB.zipAscent / Ascent i filter (with bass control set at -3dB)
Ascent iAscent(i).zipAscent / Ascent i filter (with bass control set at flat)
ClarityClarity.zipClarity filter
Classic ESL 9Classic ESL 9.zipClassic ESL 9 filter
CLS IICLS2(a)(z)_BassAssist.zipCLS II / CLS IIa / CLS IIz filter (augmenting speaker's low frequency response below 80Hz)
CLS IICLS2(a)(z)_PlayBelow.zipCLS II / CLS IIa / CLS IIz filter (matching speaker's natural low frequency response)
CLS IIaCLS2(a)(z)_BassAssist.zipCLS II / CLS IIa / CLS IIz filter (augmenting speaker's low frequency response below 80Hz)
CLS IIaCLS2(a)(z)_PlayBelow.zipCLS II / CLS IIa / CLS IIz filter (matching speaker's natural low frequency response)
CLS IIzCLS2(a)(z)_BassAssist.zipCLS II / CLS IIa / CLS IIz filter (augmenting speaker's low frequency response below 80Hz)
CLS IIzCLS2(a)(z)_PlayBelow.zipCLS II / CLS IIa / CLS IIz filter (matching speaker's natural low frequency response)
CLXCLX.zipCLX / CLX Art filter
CLX ArtCLX.zipCLX / CLX Art filter
EFXEFX.zipEFX filter
ElectroMotion ESLElectromotionESL.zipElectroMotion ESL filter
ElectroMotion ESL XElectromotionESL-X.zipElectroMotion ESL X filter
EthosEthos-10dB.zipEthos filter (with bass control set to -10dB)
EthosEthos.zipEthos filter (with bass control set to 0dB)
Expression ESL 13AExpression ESL 13A (Bass Augment).zipAdds deep bass to the 13A running full range. Augments the 13A’s output.
Expression ESL 13AExpression ESL 13A (Bass reduced 10dB).zipDesigned to be used with the 13A bass control set to -10dB. Creates an actual crossover.
Impression ESL 11AImpression ESL 11A (Bass Augment).zipAdds deep bass to the 11A running full range. Augments the 11A’s output.
Impression ESL 11AImpression ESL 11A (Bass reduced 10dB).zipDesigned to be used with the 11A bass control set to -10dB. Creates an actual crossover.
Monolith IIIMonolith IIIx 30Hz 0dB.zipMonolith III with IIIx Crossover (with 30Hz set at 0dB)
Monolith IIIMonolith_IIIp.zipMonolith III with IIIp Crossover (with bass contour set to Out)
Monolith IIIMonolith_IIIx_50Hz_-4dB.zipMonolith III with IIIx Crossover (with 50Hz set at -4dB)
MontageMontage.zipMontage filter
MontisMontis-10dB.zipMontis filter (with bass control set at -10dB)
MontisMontis.zipMontis filter (with bass control set at 0dB)
MosaicMosaic.zipMosaic filter
Motion 10Motion 10.zipMotion 10 filter
Motion 12Motion 12.zipMotion 12 filter
Motion 15Motion 15.zipMotion 15 filter
Motion 20Motion 20.zipMotion 20 filter
Motion 35XTMotion_35XT.zipMotion 35XT filter
Motion 40Motion 40.zipMotion 40 filter
Motion 60XTMotion_60XT.zipMotion 60XT filter
Motion LX16Motion LX16.zipMotion LX16 filter
OdysseyOdyssey.zipOdyssey filter (with bass control set at flat)
PrefacePreface.zipPreface filter
ProdigyProdigy.zipProdigy filter (with bass control set at flat)
PurityPurity.zipPurity filter
QuestQuest(z) -3dB.zipQuest / Quest z filter (with bass contour switch set to -3 dB for Quest or -5dB for Quest Z)
QuestQuest(z) Flat.zipQuest / Quest z filter (with bass contour switch set to flat)
Quest zQuest(z) -3dB.zipQuest / Quest z filter (with bass contour switch set to -3 dB for Quest or -5dB for Quest Z)
Quest zQuest(z) Flat.zipQuest / Quest z filter (with bass contour switch set to flat)
Renaissance ESL 15ARenaissance ESL 15A (Bass Augment).zipAdds deep bass to the 15A running full range. Augments the 15A’s output.
Renaissance ESL 15ARenaissance ESL 15A (Bass reduced 10dB).zipDesigned to be used with the 15A bass control set to -10dB. Creates an actual crossover.
reQuestReQuest flat.zipReQuest filter (with bass contour switch set to flat)
ScenarioScenario.zipScenario filter
SL3SL3 -3dB.zipSL3 filter (with bass control set to -3dB)
SL3SL3 flat.zipSL3 filter (with bass control set to flat)
SourceSource.zipSource filter
SpireSpire -10dB.zipSpire filter (with 35Hz level control set to -10dB)
SpireSpire.zipSpire filter (with 35Hz level control set to 0dB)
SummitSummit 25-10dB.zipSummit filter (with 25Hz level control set to -10dB and 50Hz level control set to 0dB)
SummitSummit 25_50-10dB.zipSummit filter (with 25Hz level control set to -10dB and 50Hz level control set to -10dB)
SummitSummit.zipSummit filter (with 25Hz level control set to 0dB and 50Hz level control set to 0dB)
Summit XSummitX 25-50 -10dB.zipSummit X filter (with 25Hz level control set to -10dB and 50Hz level control set to -10dB)
Summit XSummitX 25Hz-10dB.zipSummit X filter (with 25Hz level control set to -10dB and 50Hz level control set to 0dB)
Summit XSummitX.zipSummit X filter (with 25Hz level control set to 0dB and 50Hz level control set to 0dB)
TheosTheos.zipTheos filter
VantageVantage -10dB.zipVantage filter (with 35Hz level control set at -10dB)
VantageVantage.zipVantage filter (with 35Hz level control set at 0dB)
VistaVista.zipVista filter

Firmware Updates

Updating your Subwoofer's Firmware:

Please note, the subwoofer will load whichever firmware revision is on the connected flash drive—even if the firmware revision on the flash drive is older than what is currently loaded on your subwoofer. The latest version of the firmware is available on this page.

To check which revision your subwoofer currently has installed, press the Custom Low-Pass button and hold it for 3 seconds. The Tone Sweep LED light will blink a number of times that is equal to the current revision number (e.g. two blinks = revision 2 firmware).

Please note, updating the firmware should not erase settings for PBK (Perfect Bass Kit) and the Custom Low-Pass filter. A notice will be posted on our website alongside the firmware download if, for some unforeseen reason, a specific firmware revision must erase these settings—otherwise, these setting should still be in place after a firmware update.

  1. Download the latest firmware file for your subwoofer model. Save the firmware file in the root directory of a USB flash drive (a USB flash drive was included with your new subwoofer, but any flash drive 32GB or smaller should work). To assure a successful upload to your subwoofer we recommend having no other files or folders on the flash drive—the subwoofer can only load one file at a time.
  2. Unplug the subwoofer from the AC outlet.
  3. Insert the flash drive into the USB Input on the back of the subwoofer.
  4. Reconnect the subwoofer to the AC outlet. The USB Status LED will continually blink red-green-red-green while the firmware is being updated—this blinking may pause momentarily during the update. Do not remove the flash drive until the LED stops blinking and shows a solid color for at least 5 seconds.

Please review your subwoofer's manual for more information.

ModelFilter File (click to download)Additional Description
BalancedForce 210BalancedForce-V0-R02.9.binFirmware Rev 2.9 (Updated Dec-2013)
BalancedForce 212BalancedForce-V0-R02.9.binFirmware Rev 2.9 (Updated Dec-2013)

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