[z,fs]=audioread('sample.aac');
bfil=fft(z); %fft of input signal
wn=[2000 4400]/(fs/2);   %bandpass
[b,a]=butter(6,wn);
fvtool(b,a);
f=filter(b,a,z);
afil=fft(f);
sound(f,fs)
subplot(3,1,1);plot(real(z));
title('Respon Waktu Sinyal Asli');
xlabel('frequency');ylabel('magnitude');
subplot(3,1,2);plot(real(bfil));
title('Respon Frekuensi Sinyal Asli');
xlabel('frequency');ylabel('magnitude');
subplot(3,1,3);plot(real(afil));
title('Respons Frekuensi Sinyal Setelah di Filter');
xlabel('frequency');ylabel('magnitude');