Obtaining frequency response from transfer function

Hi there,

I am trying to find the frequency response of this transfer function.

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This is my effort which I believe to be correct of putting it into MATLAB. I do change the format a little to avoid divide by zero errors.

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And here is my MATLAB code:

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%%Modelling an amplifier
clc; clear; close all;

%%All important D factor (Distortion, also known in some parts as Distance)
Dist = 1;

fs = 44100;   % Sampling frequency (Hz)
T = 1/fs;     % Timestep

N = 1000;     % Samples

f = -fs/2:fs/N:fs/2 - fs/N;

%%Circuit Parameters - Level 1
Rt = Dist * 100e3;
Rb = (1-Dist) * 100e3 + 4.7e3;
Cz = 1e-6;
Cc = 250e-12;

%%Substitutions - Level 2
a = Rt*Cc;
b = Rb*Cz;
c = Rb*Cc;

%%Substitutions - Level 3
x = a*b*c;
y = a*b + a*c + b*c;
z = a*c + b*c;

% Num and den of H(s)
sA = [c z x];
sB = [c y x];

% S domain frequency response
hS = freqs(sB,sA,f);

% Plot
semilogx(f, 20*log(abs(hS)));

xlabel('Frequency (Hz)');
ylabel('Magnitude Response (dB)');
title('H(s)');

   end

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This is the result I am going for.. (Dist == D)

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The result I am getting is blatantly wrong.

Any help would be very appreciated!

Cheers