Can anybody help me with the following code?

[z,fs]=audioread('bird1.mp3'); 
bfil=fft(z); %fft of input signal
wn=[4000 8000]/(fs/2);   %bandpass
[b,a]=butter(6,wn);
fvtool(b,a);

I was able to draw the graph for this particular range. Can i draw wn=[8000 12000]/(fs/2); n the same graph itself, instead of another figure???

Answer 1

[GEEVARGHESE TITUS]

I not sure of obtaining multiple plots in the same window using fvtool. Instead you can get what you required, using functions freqz(), plot() and hold on.

[z,fs]=audioread('bird1.mp3'); 
bfil=fft(z); %fft of input signal
wn=[4000 8000]/(fs/2);   %bandpass
[b,a]=butter(6,wn);
[h,w]=freqz(b,a);
plot(w/pi,20*log10(abs(h)),'r');
hold on;
wn=[8000 12000]/(fs/2);
[b,a]=butter(6,wn);
[h,w]=freqz(b,a);
plot(w/pi,20*log10(abs(h)),'b');

[Darsana P M]

That really helped me a lot.Thanks a lot!!!! I have a doubt. Can i use this concept of butterworth filters if i want to divide the frequencies into 10-20Khz, 20-30Khz and so on??Which parameter should i change?

[GEEVARGHESE TITUS]

Sorry , i was not able to understand your question? Elaborate please. Are you thinking of bank of butterworth filers?

[Darsana P M]

yaa exactlty. How can i write a code for a bank of butterworth filters? Such that i can divide the given audio signal into different bands ie 10-20Khz, 20-30Khz and so on.