#### Matlab Code for Inverse Filtering

Below is the matlab source code used to extract the main Helmholtz air mode from the guitar body impulse response in Figures 8.14 through 8.17:

freq = 104.98; % estimated peak frequency in Hz bw = 10; % peak bandwidth estimate in Hz R = exp( - pi * bw / fs); % pole radius z = R * exp(j * 2 * pi * freq / fs); % pole itself B = [1, -(z + conj(z)), z * conj(z)] % numerator r = 0.9; % zero/pole factor (notch isolation) A = B .* (r .^ [0 : length(B)-1]); % denominator residual = filter(B,A,bodyIR); % apply inverse filter

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Empirical Notes on Inverse Filtering