FIR and IIR Comb FIlter

Hello, I'm trying to build an FIR and IIR comb filter to demonstrate different effects on a wav file, can anyone direct me to useful resources?

Answer 1

[Star Strider]

One example of a FIR comb filter is Vibration Analysis FFT - Cut off frequency

I like IIR filters, because at least in my experience they are computationally more efficient (specific elliptic designs), however it necessary to put them in series in a loop to do the same sort of thing.

One example:

Fs = 44100;                                                             % Sampling Frequency
Fn = Fs/2;                                                              % Nyquist Frequency
Rp =  1;                                                                % Passband Ripple (Attenuation)
Rs = 50;                                                                % Stopband Ripple (Attenuation)
pbmtx = [48 51] + (0:50:150).';
for k1 = 1:size(pbmtx,1)
    Ws = pbmtx(k1,:)/Fn;
    Wp = Ws + [-2 2]/Fn;
    [n,Wp] = ellipord(Wp,Ws,Rp,Rs);
    [z,p,k] = ellip(n,Rp,Rs,Wp,'stop');
    [sos{k1},g(k1)] = zp2sos(z,p,k);
    [h(:,k1),f] = freqz(sos{k1},2^14,Fs);
end

figure
hold on
for k = 1:size(pbmtx,1)
    plot(f, db(abs(h(:,k))/max(abs(h(:,k)))))                           % Normalisation For Display Purposes, Since ‘freqz’ Does Not Always Calculate The Magnitudes Correctly 
end
axis([min(f) 300    -100 10])
grid

Use filtfilt to do the actual filtering with respect to both of these, once with the FIR filter and in a loop with the IIR filters, with the input of one filter being the output of the filter in the previous iteration.