Hi Nathan,
The syntax of freqz that you were using in your code above expects w to be normalized fequency. I ran your code and its not normalized. You can specify frequency in Hz by also specifying the sample rate.
Another issue (updated answer): is that the default orientation of the coefficients output from designParamEQ was not the orientation expected by fvtool and freqz.
M = readtable('spec.xlsx','Sheet','TF');
Fs = 96e3;
N = 2;
G = -5; % 5 dB
Wo = 1000/(Fs/2); % center frequency
BW = 1; %bandwidth in octaves
Q = sqrt(2^BW)/((2^BW)-1); % convert bandwidth to Q
BWnorm = Wo/Q; % then to normalized bandwidth
[b,a] = designParamEQ(N1,G,Wo,BWnorm,'Orientation','row');
fvtool([b,a])
%%
% Magnitude and phase of parametric EQ
f = M.Frequency_Hz;
h = freqz([b,a],f,Fs);
magdB = mag2db(abs(h));
% plot
semilogx(f,magdB) % the filter
grid on
% ylim([-24 24]);
% xlim([20 20000]);
xlabel('Frequency')
ylabel('Magnitude')
legend('Mag Parametric EQ','Location','best');
