GraphicEQFract32

Overview

10 band graphic equalizer in which each section has order 8.

Discussion

This subsystem implements a complete multiband graphic equalizer. The number of bands and filter order is specified at instantiation time. The subsystem consists of a cascade of individual band pass filters.

The subsystem supports floating-point and fract32 data. The data type to use is specified at instantiation time. For floating-point data, the subsystem using the graphic_eq_band_module.m module. For fract32 data, the subsystem using the graphic_eq_band_fract32_module.m module. See these modules for additional details.

The upper and lower band edges of the bandpass filter modules are set to logarithmic spacing between 20 Hz and 20 kHz. These default values can be overridden after the subsystem has been created.

Type Definition

-Not Shown-

Pins

Input Pins

Name: in

Description: Audio Input

Data type: fract32

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: Audio output

Data type: fract32

Scratch Pins

Channel count: 1

Block size: 32

Sample rate: 48000

Channel count: 1

Block size: 32

Sample rate: 48000

MATLAB Usage

File Name: graphic_eq_fract32_subsystem.m

CODE

 SYS=graphic_eq_fract32_subsystem(NAME, NBANDS, ORDER)
 Creates a multi-band graphic EQ subsystem constructed as a cascade
 of individual sections.  Each section is realized as a
 graphic_eq_band_module.m.  Arguments:
    NAME - name of the module.
    NBANDS - number of bands.  By default, NBANDS=10.
    ORDER - order of each filter section.  This must equal 4, 8, or 12.
            By default, ORDER=8.
 As a rule of thumb, you can use 4th order filters for NBANDS=1 to 5;
 8th order filters for NBANDS=6 to 15; and 12th order filter for
 NBANDS=16 and above.
 Internally, the system uses a cascade of graphic_eq_band_module.m
 modules.  The initial upper and lower band edges are set to provide a
 roughly logarithmic spacing for the filters.  The band edge frequencies
 may be changed after instantiation.