This version (18 May 2021 09:03) was approved by John Joseph.The Previously approved version (19 Jan 2021 05:45) is available.Diff

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RMS Eq Blend


The RMS Equalizer blend module along with General (2nd-Order) block gives access to a wide variety of 2nd-order (biquad)filter algorithms along with equalization. Blend factor and slew rate modifications are common for all the stages.

The available filter types are:

  • Unordered List ItemOrdered List ItemParametric
  • Shelving
  • General High-Pass
  • General Low-Pass
  • General Band-Pass
  • General Band-Stop
  • Butterworth Low-Pass / High-Pass
  • Bessel Low-Pass / High-Pass
  • Tone Control
  • IIR Coefficient (direct coefficient entry)
  • 1st-Order Low-Pass / High-Pass
  • All-pass
  • Peaking
  • Notch
  • Chebyshev Low-Pass / High-Pass


To open the filter control window, click on the icon button. Select the desired filter type from the drop-down combo-box list. The filter controls and the icon button image will change to reflect the selected filter type. Also varying the threshold values and RMS time constant values would change the output values accordingly

Targets Supported

Name ADSP-214xx ADSP-215xx/SC5xx ADAU145x/146x
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Input0AudioInput Channel 0
Blend0ControlExternal Blend pin for SingleEqExtBlend variant


——————————————— —————————— ————————————————
Output0AudioOutput channel 0

Configurable Parameters

GUI Parameter NameDefault ValueRangeFunction Description
StageX_FilterY_Boost0 dB -10 to +10 dBSet the boost value for a particular filter curve
StageX_FilterY_Frequency10000 to 96000HzCut-off frequency
StageX_FilterY_Gain0 dB-15 to +15 dBFilter Gain
StageX_FilterY_Q1.410.1 to 16Q factor of the filter
StageX_FilterY_Slope10 to 2Slope controls filter steepness and therefore the transition between the boost/cut and the flat response.
StageX_FilterY_FilterTypeParametric filterAvailable filter TypesControls the type of the filter
StageX_FilterY_EnabledOrBypassedTrueTrue/FalseEnabled/Disabled the algorithm
StageX_FilterY_PhaseFalseTrue/FalseControls the phase of coefficients in 0 degree or 180 degree phase
NumChannels11 to 20Increases or decreases the number of input and output channels. Changing this requires re-compilation
NumStages11 to 20Increases or decreases the number of filter stages. Changing this requires re-compilation
Blend 00 to 1 Blend factor for the equalizer module
SlewRate 0.010.01 to 1Defines the rate at which input takes the new value
LowerThreshold0.010.01 to 24Defines the Lower threshold for the applying the RMS Blend value
UpperThreshold 0.010.01 to 24Defines the Upper threshold for the applying the RMS Blend value
RMSTC0.0010.001 to 6Defines the RMS time constant value

Here, * X - Indicates Stage Number * Y - Indicates Filter A/Filter B

DSP Parameters

Parameter Name Description ADSP-214xx/SC5xx/215xx ADAU145x/146x
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StageX_FilterY_B0B0 Filter CoefficientFloatFixPoint8d24
StageX_FilterY_B1B1 Filter CoefficientFloatFixPoint8d24
StageX_FilterY_B2B2 Filter CoefficientFloatFixPoint8d24
StageX_FilterY_A1A1 Filter CoefficientFloatFixPoint8d24
StageX_FilterY_A2A2 Filter CoefficientFloatFixPoint8d24
StageX_Slew_LambdaExponential decay value of filter stage XFloatFixPoint8d24


  • X - Stage Number (Changes for each stage coefficients)
  • Y - Filter A/B for each stage X

resources/tools-software/sigmastudiov2/modules/filters/rmsblend.txt · Last modified: 15 May 2021 15:50 by Sreesha Y M