Hello everyone,
So, I am doing a project with a sound file of my voice and applying some filters to it and finding the fourier transforms.
My code (just a little part) is:
[y,Fs] = audioread('myvoice.m4a');
L = length(y);
f = Fs*(0:(L/2))/L;
y_HPF_270 = highpass(y,270,Fs);
P2_HPF270 = abs(yf_HPF_270/L);
P1_HPF270 = P2_HPF270(1:L/2+1);
P1_HPF270(2:end-1) = 2*P1_HPF270(2:end-1);
subplot(3,2,6);
plot(f,P1_HPF270)
title('Single-Sided Amplitude Spectrum of HPF 270Hz')
xlabel('f (Hz)')
ylabel('|P1(f)|')
From what I understand from High Pass filters is that i filters the frequencies that are below a cutoff frequency. If my cutoff frequency is 270 Hz, why do I get still frequencies below 270?
The fourier Transform graph taht I get is:
