Hi, I'm currently trying to make a lowpass filter for a sound clip with the specs of being order 128 and having a curoff frequency of 3575 Hz. Using the tf function does produce a graph, but that graph comes up as blank for any order greater than 70. People are recommending using a fir1, which, while it does produce a graph, though I'm unsure if these are correct given how I'm also getting the following error messages:
"Error using fir1>chkWindow (line 286)
Window length must be the same as the filter length.
Error in fir1>eFir1 (line 161)
wind = chkWindow(L,varargin{windIndex});
Error in fir1 (line 92)
[b,a] = eFir1(varargin{:});
Error in Lowpass (line 25)
blo = fir1(128,0.48,chebwin(35,30));"
My code is as follows:
audioread('beep.wav');
info = audioinfo('beep.wav')
filename = 'beep.wav';
audiowrite(filename,y,Fs);
[y,Fs] = audioread('beep.wav');
sound(y,Fs)
t = 0:seconds(1/Fs):seconds(info.Duration);
t = t(1:end-1);
figure(1)
plot(t,y)
xlabel('Time')
ylabel('Audio Signal')
title 'Beep Signal'
filename = 'Beep.wav';
audiowrite(filename,y,Fs);
t = (0:length(y)-1)/Fs;
bhi = fir1(34,0.48,'low',chebwin(35,30));
freqz(bhi,1)
blo = fir1(128,0.48,chebwin(35,30));
outlo = filter(blo,1,y);
subplot(2,1,1)
plot(t,y)
title('Original Signal')
ys = ylim;
subplot(2,1,2)
plot(t,outlo)
title('Lowpass Filtered Signal')
xlabel('Time (s)')
ylim(ys)
Any help explaining what is going wrong with this code would be appreciated
