Multiband Parametric EQ

Multiband parametric equalizer

Since R2021b

• 

Libraries:
Audio Toolbox / Filters

Description

The Multiband Parametric EQ block performs multiband parametric equalization independently across each channel of input using specified center frequencies, gains, and quality factors. You can configure this block with up to 10 bands. You can add low-shelf and high-shelf filters as well as highpass (low-cut) and lowpass (high-cut) filters.

Examples

Visualize Filter Response of Multiband Parametric Equalizer Block

Perform multiband parametric equalization independently across each channel of an input using specified center frequencies, gains, and quality factors.

• Open Script

Ports

Input

Port_1 — Audio input to equalizer

matrix | vector

Audio input to the equalizer, specified as one of the following:

• Matrix input –– The block treats each column of the input as an independent channel.

• Vector input –– The block treats the input as having a single channel.

Data Types: single | double

Output

Port_1 — Audio output from equalizer

matrix

Audio output from the equalizer, returned as a matrix. If you specify the input as a matrix, the block returns the output with the same size as matrix input. If you specify the input as a vector then the output is N-by-1 matrix.

Data Types: single | double

Parameters

Main

EQ order — Order of individual equalizer bands

2 (default) | even positive integer

Order of individual equalizer bands, specified as an even positive integer. All equalizer bands have the same order.

Number of bands — Number of equalizer bands

3 (default) | integer in the range [1,10]

Number of equalizer bands, specified as an integer in the range [1,10]. The number of equalizer bands does not include shelving filters, highpass filters, or lowpass filters.

Specify frequencies from input port — Specify frequencies from input port

off (default) | on

Select this parameter to specify frequencies from the input port.

Frequencies (Hz) — Center frequencies of equalizer bands

[100,181,325] (default) | row vector of length equal to Number of bands

Center frequencies of equalizer bands in Hz, specified as a row vector of length equal to Number of bands. The vector consists of real scalars in the range 0 to Input sample rate (Hz)/2.

Tunable: Yes

Dependencies

To enable this parameter, set Specify input frequencies from input port to off.

Specify peak gains from input port — Specify peak gains from input port

off (default) | on

Select this parameter to specify peak gains from input port.

Peak Gains (dB) — Peak or dip filter gains

[0,0,0] (default) | row vector of length equal to Number of bands

Peak or dip filter gains, specified as a row vector of length equal to Number of bands in dB. The vector consists of real scalars in the range [–inf,20].

Tunable: Yes

Dependencies

To enable this parameter, set Specify peak gains from input port to off.

Specify quality factors from input port — Specify quality factors from input port

off (default) | on

Select this parameter to specify quality factors from the input port.

Quality factors — Quality factors of equalizer bands

[1.6,1.6,1.6] (default) | row vector

Quality factors of equalizer bands, specified as a row vector of length equal to Number of bands.

Tunable: Yes

Dependencies

To enable this parameter, set Specify quality factor from input port to off.

Inherit sample rate from input — Specify sample rate from input port

off (default) | on

Select this parameter to specify sample rate from the input port.

Input sample rate (Hz) — Input sample rate

44100 (default) | positive scalar

Input sample rate, specified as a positive scalar in Hz.

Tunable: Yes

Dependencies

To enable this parameter, set Inherit sample rate from input port to off.

Visualize filter response — Visualize magnitude response of equalizer

button

This button plots the filter responses of low-shelf, high-shelf, highpass (low-cut), and lowpass (high-cut) filters in a magnitude (dB) vs. frequencies (Hz) plot.

Note

The block does not support filter visualization if any parameters are specified from input ports or the sample rate is inherited.

Variable name — Variable name of exported filter

myFilt (default) | valid variable name

Name of the variable in the base workspace to contain the filter when it is exported. The name must be a valid MATLAB^® variable name.

Overwrite variable if it already exists — Overwrite variable if it already exists

on (default) | off

When you select this parameter, exporting the filter overwrites the variable specified by the Variable name parameter if it already exists in the base workspace. If you do not select this parameter and the specified variable already exists in the workspace, exporting the filter creates a new variable with an underscore and a number appended to the variable name. For example, if the variable name is var and it already exists, the exported variable will be named var_1.

Export filter to workspace — Export filter to workspace

button

Export the filter to the base workspace in the variable specified by the Variable name parameter.

Tips

• You cannot export the filter if you have enabled the Inherit sample rate from input parameter and the model is not running.

• You cannot export the filter if you are specifying filter characteristics from input ports.

Advanced

Add low-shelf filter — Add low-shelf filter to equalizer

off (default) | on

Select this parameter to add a low-shelf filter to your equalizer.

Specify low-shelf cutoff from input port — Specify low-shelf cutoff frequency from input port

off (default) | on

Select this parameter to specify the cutoff frequency of the low-shelf filter from the input port.

Dependencies

To enable this parameter, set Add low-shelf filter to on.

Low-shelf cutoff frequency (Hz) — Low-shelf cutoff frequency

200 (default) | scalar

The cutoff frequency of the low-shelf filter, specified as a scalar greater than or equal to 0 in Hz.

Tunable: Yes

Dependencies

To enable this parameter, set Add low-shelf filter to on and Specify low-shelf cutoff from input port to off.

Specify low-shelf slope from input port — Specify low-shelf slope

off (default) | on

Select this parameter to specify low-shelf slope from the input port.

Dependencies

To enable this parameter, set Add low-shelf filter to on.

Low-shelf filter slope — Low-shelf slope

1.5 (default) | positive scalar

The slope of the low-shelf filter, specified as a positive scalar.

Tunable: Yes

Dependencies

To enable this parameter, set Add low-shelf filter to on and Specify low-shelf slope from input port to off.

Specify low-shelf gain from input port — Specify low-shelf gain from input port

off (default) | on

Select this parameter to specify the gain of the low-shelf filter from the input port.

Dependencies

To enable this parameter, set Add low-shelf filter to on.

Low-shelf filter gain (dB) — Low-shelf gain

0 (default) | real scalar

The gain of the low-shelf filter, specified as a real scalar.

Tunable: Yes

Dependencies

To enable this parameter, set Add low-shelf filter to on and Specify low-shelf gain from input port to off.

Add high-shelf filter — Add high-shelf filter to equalizer

off (default) | on

Select this parameter to add a high-shelf filter to your equalizer.

Specify high-shelf cutoff from input port — Specify high-shelf cutoff frequency from input port

off (default) | on

Select this parameter to specify the cutoff frequency of the high-shelf filter from the input port.

Dependencies

To enable this parameter, set Add high-shelf filter to on.

High-shelf cutoff frequency (Hz) — High-shelf cutoff frequency

15e3 (default) | scalar

The cutoff frequency of the high-shelf filter, specified as a scalar greater than or equal to 0 in Hz.

Tunable: Yes

Dependencies

To enable this parameter, set Add high-shelf filter to on and Specify high-shelf cutoff from input port to off.

Specify high-shelf slope from input port — Specify high-shelf slope from input port

off (default) | on

Select this parameter to specify the slope of the high-shelf filter from the input port.

Dependencies

To enable this parameter, set Add high-shelf filter to on.

High-shelf filter slope — High-shelf slope

1.5 (default) | positive scalar

The slope of the high-shelf filter, specified as a positive scalar.

Tunable: Yes

Dependencies

To enable this parameter, set Add high-shelf filter to on and Specify high-shelf slope from input port to off.

Specify high-shelf gain from input port — Specify high-shelf gain from input port

off (default) | on

Select this parameter to specify the gain of the high-shelf filter from the input port.

Dependencies

To enable this parameter, set Add high-shelf filter to on.

High-shelf filter gain (dB) — High-shelf gain

0 (default) | real scalar

The gain of the high-shelf filter, specified as a real scalar.

Tunable: Yes

Dependencies

To enable this parameter, set Add high-shelf filter to on and Specify high-shelf gain from input port to off.

Add lowpass filter — Add lowpass filter to equalizer

off (default) | on

Select this parameter to add a lowpass filter to your equalizer.

Specify lowpass cutoff from input port — Specify lowpass cutoff frequency from input port

off (default) | on

Select this parameter to specify the cutoff frequency of the lowpass filter from the input port.

Dependencies

To enable this parameter, set Add lowpass filter to on.

Lowpass cutoff frequency (Hz) — Lowpass cutoff frequency

18e3 (default) | scalar

The cutoff frequency of the lowpass filter, specified as a scalar greater than or equal to 0 in Hz.

Tunable: Yes

Dependencies

To enable this parameter, set Add lowpass filter to on and Specify lowpass cutoff from input port to off.

Specify lowpass slope from input port — Specify lowpass slope from input port

off (default) | on

Select this parameter to specify the slope of the lowpass filter from the input port.

Dependencies

To enable this parameter, set Add lowpass filter to on.

Lowpass filter slope — Lowpass slope

12 (default) | real scalar in the range [0:6:48]

The slope of the lowpass filter, specified as a real scalar in the range [0:6:48] in dB/octave. Values that are not multiples of 6 are rounded to the nearest multiple of 6.

Tunable: Yes

Dependencies

To enable this parameter, set Add lowpass filter to on and Specify lowpass slope from input port to off.

Add highpass filter — Add highpass filter to equalizer

off (default) | on

Select this parameter to add a highpass filter to your equalizer.

Specify highpass cutoff from input port — Specify highpass cutoff frequency from input port

off (default) | on

Select this parameter to specify the cutoff frequency of the highpass filter cutoff from the input port.

Dependencies

To enable this parameter, set Add highpass filter to on.

Highpass cutoff frequency (Hz) — Highpass cutoff frequency

20 (default) | nonnegative real scalar

The cutoff frequency of the highpass filter, specified as a real scalar greater than or equal to 0 in Hz.

Tunable: Yes

Dependencies

To enable this parameter, set Add highpass filter to on and Specify highpass cutoff from input port to off.

Specify highpass slope from input port — Specify highpass slope from input port

off (default) | on

Select this parameter to specify the slope of the highpass filter from the input port.

Dependencies

To enable this parameter, set Add highpass filter to on.

Highpass filter slope — Highpass slope

30 (default) | real scalar in the range [0:6:48]

The slope of the highpass filter, specified as a real scalar in the range [0:6:48] in dB/octave. Values that are not multiples of 6 are rounded to the nearest multiple of 6.

Tunable: Yes

Dependencies

To enable this parameter, set Add highpass filter to on and Specify highpass slope from input port to off.

Oversample — Oversample toggle

off (default) | on

Oversample toggle, specified as one of the following:

• off –– Run the multiband parametric equalizer at the input sample rate.

• on –– Run the multiband parametric equalizer at two times the input sample rate. Oversampling minimizes the frequency-warping effects introduced by the bilinear transformation.

A halfband interpolator implements oversampling before equalization. A halfband decimator reduces the sample rate back to the input sampling rate after equalization.

Simulate using — Specify type of simulation to run

Code generation (default) | Interpreted execution

Type of simulation to run, specified as one of the following:

• Interpreted execution –– Simulate model using the MATLAB interpreter. This option shortens startup time and has simulation speed comparable to Code generation. In this mode, you can debug the source code of the block.

• Code generation –– Simulate model using generated C code. The first time you run a simulation, Simulink^® generates C code for the block. The C code is reused for subsequent simulations as long as the model does not change. This option requires additional startup time but the speed of the subsequent simulations is faster than Interpreted execution.

Tunable: No

Block Characteristics

Data Types	double | single
Direct Feedthrough	no
Multidimensional Signals	no
Variable-Size Signals	yes
Zero-Crossing Detection	no

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2021b