Maxime Dolberg

[HELP] How to code an equalizer on DSP ?

Discussion created by Maxime Dolberg on Jan 30, 2013
Latest reply on Jul 2, 2013 by xiangjun.rong



I actualy try to code a digital equalizer with the 56k DSP. I would like to know if my way to make it is good because the final response isn't look like I want.


1) take sample x(n) from ADC
2) calculate x(n) for each filter and store each results

3) Pop out x(n), x(n)', x(n)'', ...  and add each one to form y(n)

4) send y(n) to DAC


Before building a complete equalizer, I only use 3 IIR filters for testing the method.


1st filter : Lowpass Fcutoff = 1kHz

2nd filter : Band pass Fcentral 2kHz, Bandwidth 2kHz

3rd filter : Band pass Fcentral 4kHz, Bandwidth 4kHz


So the ideal bode graph should be a straigth line from 0 to 4,2kHz and then go down. But in practice it isn't look like this.


Does my method is good ? Do i miss something ?