Wiki

This version is outdated by a newer approved version.DiffThis version (03 Aug 2018 11:56) was approved by Suhasini Raghuram.The Previously approved version (20 Dec 2017 08:51) is available.Diff

This is an old revision of the document!


General EQ Blend

Click here to return to the Filters page

The 'General EQ Blend' block blends the filter coefficients of two second order filters according to the blend factor specified and performs filtering opertaion



This block gives access to a wide variety of 2nd-order (biquad)filter algorithms. The blend factor can be entered(0-1) or changed using the slider. The Slew time can be entered in seconds (0-1) to slew from the initial blend factor to the target value.

  • The available filter types are:
  • Parametric
  • 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
  • 1st-Order Low-Pass / High-Pass
  • All-pass
  • Peaking
  • Notch
  • Chebyshev Low-Pass / High-Pass

The slewing functionality is added for smooth transition from one blend factor to another when the blending factor is changed. The slewing takes place approximately in the time set by the user in the GUI. The slew time can be entered in the GUI slew Text box. The slew time range is limited between (0 to 1 second).

Input Pins

NameFormat [int/dec] - [control/audio]Function Description
Pin 0: Filter In1decimal - audioInput to the filter



Output Pins

NameFormat [int/dec] - [control/audio]Function Description
Pin 0: Filter Out1decimal - audioFiltered output


Configuration


GUI Control NameDefault ValueRangeFunction Description
Enable/Bypass - Filter 1 Enabled True/False Enabling or disabling of filter. On bypass, the input signal is passed through without any processing.
Phase - Filter 1In-PhaseTrue/FalseEnabling the button, will invert the filter phase.
Frequency - Filter 11000 Hz0 - 96k HzCenter frequency of the filter
Enable/Bypass - Filter 2EnabledTrue/FalseEnabling or disabling of filter. On bypass, the input signal is passed through without any processing.
Phase - Filter 2In-PhaseTrue/FalseEnabling the button, will invert the filter phase.
Frequency - Filter 21000 Hz0 - 96k HzCenter frequency of the filter
Slew0.01 s0 - 1 secondsSet the time to slew from one set of coefficients to another.
Blend00-1Set the blend between two sets of filters


Click on the icon to configure the filters. 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.

The GUI controls for various types of filters are given below.

Parameteric

GUI Control NameDefault ValueRangeFunction Description
Frequency 1000Hz 0-96kHz Cut off frequency of the filter
Gain0dB-15 - 15 dBdB gain of the filter coefficients.
Q1.410-16Q Factor for filter calculations

Shelving

GUI Control NameDefault ValueRangeFunction Description
Shelf typeLow ShelfLow Shelf/High ShelfShelving type for the filter
Frequency1000Hz0-96kHzCut off frequency of the filter
Gain0dB-15 - 15 dBdB gain of the filter coefficients
Q1.410-16Q Factor for filter calculations
Slope10-2Slope



General

GUI Control NameDefault ValueRangeFunction Description
TypeLow Pass FilterLow Pass/High Pass/BandPass/BandStopGeneral filter type
Frequency1000Hz0-96kHz Cut off frequency of the filter
Gain0dB-15 - 15 dBdB gain of the filter coefficients
Q1.410-16Q Factor for filter calculations

Butterworth/Bessel

GUI Control NameDefault ValueRangeFunction Description
TypeBessel Low PassBessel Low Pass/Bessel High Pass/Butterworth Low Pass/Butterworth High PassFilter type
Frequency1000Hz0-96kHzCut off frequency of the filter
Gain0dB-15 - 15 dBdB gain of the filter coefficients

Tone Control

GUI Control NameDefault ValueRangeFunction Description
Treble Frequency1000Hz0-96kHzTreble Cut off frequency of the filter
Treble Gain0dB-15 - 15 dBTreble dB gain of the filter coefficients
Bass Frequency1000Hz0-96kHzBass Cut off frequency of the filter
Bass Gain0dB-15 - 15 dBBass dB gain of the filter coefficients

IIR Coefficient

GUI Control NameDefault ValueRangeFunction Description
b01-100 to 100B0 coefficient for the filter
b10-100 to 100B1 coefficient for the filter
b20-100 to 100B2 coefficient for the filter
a10-100 to 100A1 coefficient for the filter
a20-100 to 100A2 coefficient for the filter

First Order Filters

GUI Control NameDefault ValueRangeFunction Description
Filter Frequency1000Hz0-96kHzCut off frequency of the filter
Active Checked Checked/UncheckedIndicates whether the filter is active
TypeHigh for 1st filter,Low - for second filterLow/High/All passType of the filter
Gain0dB-15 - 15 dBdB gain of the filter coefficients
Q1.410-16Q Factor for filter calculations

All Pass,Peaking,Notch

GUI Control NameDefault ValueRangeFunction Description
Frequency1000Hz0-96kHzCut off frequency of the filter
Gain0dB-15 - 15 dBdB gain of the filter coefficients
Q1.410-16Q Factor for filter calculations

Chebyshev

GUI Control NameDefault ValueRangeFunction Description
Frequency1000Hz0-96kHzCut off frequency of the filter
Gain0dB-15 - 15 dBdB gain of the filter coefficients
Ripple0.10-10Ripple Factor for filter calculations


DSP Parameter Information

GUI Control NameCompiler NameFunction Description
F1_B2_BlendEQSPAlg1F1_B2_1Bi-quad filter coefficient B2 for filter 1
F1_B1_BlendEQSPAlg1F1_B1_1Bi-quad filter coefficient B1 for filter 1
F1_B0_BlendEQSPAlg1F1_B0_1Bi-quad filter coefficient B0 for filter 1
F1_A2_BlendEQSPAlg1F1_A2_1Bi-quad filter coefficient A2 for filter 1
F1_A1_BlendEQSPAlg1F1_A1_1Bi-quad filter coefficient A1 for filter 1
F2_B2_BlendEQSPAlg1F2_B2_1Bi-quad filter coefficient B2 for filter 2
F2_B1_BlendEQSPAlg1F2_B1_1Bi-quad filter coefficient B1 for filter 2
F2_B0_BlendEQSPAlg1F2_B0_1Bi-quad filter coefficient B0 for filter 2
F2_A2_BlendEQSPAlg1F2_A2_1Bi-quad filter coefficient A2 for filter 2
F2_A1_BlendEQSPAlg1F2_A1_1Bi-quad filter coefficient A1 for filter 2
Lambda_BlendEQSPAlg1lambda_1time_constant = slew_time/(PI * 1.5),Lambda_= exp(-1/(time_constant*FS)) where,slew_time is the time required to slew from initial to final value of coefficient.
BlendFactorBlendEQSPAlg1blend_factor_1Blending factor.


Here,

  • Green - Algorithm Name
  • Red - Instance Number (Changes for each instance)
  • Blue - Parameter Name
  • Brown - Stage number

Note: The algorithm names for different algorithms for this module are:

  • Blend EQ single precision algorithm(ADAU145x): BlendEQSPAlg
  • Blend EQ double precision algorithm(ADAU145x): BlendEQDPAlg
  • Blend EQ single precision algorithm(ADSPSC5xx): MChBlendFiltAlg
  • Blend EQ extended precision algorithm(ADSPSC5xx): MChBlendFiltEPAlg

—-

Supported ICs

  1. ADAU145x
  2. ADSPSC5xx





resources/tools-software/sigmastudio/toolbox/filters/generaleqblend.1533289380.txt.gz · Last modified: 03 Aug 2018 11:43 by Suhasini Raghuram