Audio equalizer

Task is to design a 10-band software
audio equalizer.
1/5/2017Audio Equalizer.............................................Hasham_Khan

 Open Matlab
 Using “ guide ” function create a new GUI

 For 10 bands Audio Equalizer we need 10 sliders…
so select 10 sliders

 After the completion of previous step your design will be like this ;

 Define the values for each slider handles
• global stop C Fs;
• stop=1;
• Fs=44100;
• C=zeros(1,10);
Slider 1 values are as follow;
• set(handles.slider1,'min',-20);
• set(handles.slider1,'max',20);
• set(handles.slider1,'value',0);
• set(handles. slider1,'SliderStep',[0.025,0.05]);
• set(handles. slider1,'string',num2str(0));
Repeat the above steps for all 10 Sliders

 Double click on each slider and click “ callback”
and “ CreateFtn ”…By clicking both you will see both functions
in your m file

 To get the different values of slider add “get” function
• % Executes on slider movement.
• function slider1_Callback(hObject, eventdata, handles)
• global C;
• C(1)=get(hObject,'value');
• set(handles.slider1_val,'string',num2str(C(1)));
• % --- Executes during object creation, after setting all properties.
• function slider1_CreateFcn(hObject, eventdata, handles)
• if isequal(get(hObject,'BackgroundColor'),
get(0,'defaultUicontrolBackgroundColor'))
• set(hObject,'BackgroundColor',[.9 .9 .9]);
• end
Repeat the above steps for all 10 sliders

 To add “Load”, “ Reset ”, “ Play ” ,“ Stop ’’ buttons use the Push button
in the GUI
 Double click on Push button and change the string and tag as load , reset ,
play and stop.

 Now after adding the button your design will be like this ;

 Double click on each button and select callback function
For Reset button :
• set(handles.slider1_val,'string',num2str(0));
• set(handles.slider1_var,'value',0);
Repeat the above step for all 10 sliders
For Load button :
• % -Executes on button press in load.
• function load_Callback(hObject, eventdata, handles)
• global file_name;
• file_name=uigetfile('*wav','hasham .wav');

For Stop and Play Button :
• % --- Executes on button press in play.
• function play_Callback(hObject,
eventdata, handles)
• global stop file_name C;
• stop=1;
• equalizer_play();
• function equalizer_play()
• global stop file_name C;
• [x,Fs]=wavread(file_name);
• [a,b]=coef();
• l_bucata=2*Fs;
• Nb=round(length(x)/l_bucata);
• y=0;
• for i=1:floor(Nb)
• bucata=x((i-1)*l_bucata+1:i*l_bucata);
• for k=1:5
• y=y+filter(10^(C(k)/20)*b{k},a{k},bucat
a);
• if(stop==0)
• break;
• end
• end
• wavplay(y,Fs,'async');
• y=0;
• if(stop==0)
• break;
• end
• end
• % --- Executes on button press in stop.
• function stop_Callback(hObject, eventdata,
handles)
• global stop;
• stop=0;

 Add Edit Text to each slider and double click the edit text icon and select
“callback” and “CreateFtn” for each slider

 After adding the edit text to each slider your design will be like this ;

 To have the value of each slider add the below code to each slider;
 function slider1_val_Callback(hObject, eventdata, handles)
 global C;
 C(1)=str2num(get(hObject,'string'));
 minn=get(handles.C1_var,'min');maxx=get(handles.C1_var,'max');
 if(C(1)<minn || C(1)>maxx)
 C(1)=get(handles.C1_var,'value');set(hObject,'string',num2str(0));
 else set(handles.slider1_var,'value',C(1));
 end
 function slider1_val_CreateFcn(hObject, eventdata, handles)
 if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
 set(hObject,'BackgroundColor','black');
 end
Repeat the above step for all 10 sliders

 Add equalizer plot and filter function in the code. As the equalizer is of
10 band so we have to design 10 filters.

 After adding the equalizer plot your design will be like this ;

 So your design of 10 Band Audio Equalizer is ready now run the code

Thank You
Prepared by
Hasham Khan
hkhan.msee16seecs@seecs.edu.pk
NUST School of Electrical Engineering and Computer Science(SEECS)

Audio equalizer

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Audio equalizer

Similar to Audio equalizer (20)

Recently uploaded

Recently uploaded (20)

Audio equalizer