Effacer les filtres
Effacer les filtres

Filtering a signal out of multiple frequencies without for loop

8 vues (au cours des 30 derniers jours)
ytzhak goussha
ytzhak goussha le 17 Mar 2020
Hello MATLABers,
I am trying to filter out a humming noise from my recordings. The noise has a frequency of 20kHz and it's harmonics (40,60,80 kHz).
I want to filter out all the noisy parts with one pass over the signal and the only solution I have managed to come up with is by removing each frequency with a for loop (see code). This takes a lot of time, I need to filter about 2 hours of audio recordings with 250k sampling rate.
My question is, is there a method to filter out all the desired frequencies in one pass instead of multiple passes to save computational time.
Fs = 250000; %Sampling rate
filtered =sig; %sig is a vector of the signal to be filtered
%The frequency of the noise to be filtered
onset = 19700;
offset = 20000;
times = [];
n=4; %Number of harmonics (n=1: 20, n=2: 40, n=3: 60, m=4: 80)
for k = 1:n
%Is there a filter that can remove multiple bands at onces?
d = designfilt('bandstopiir','FilterOrder',2, ...
'HalfPowerFrequency1',onset*k,'HalfPowerFrequency2',offset*k, ...
filtered = filtfilt(d,filtered);
times = [times,toc];

Réponse acceptée

Raunak Gupta
Raunak Gupta le 19 Mar 2020
There is a similar question which is nicely explained by Star Strider, this can help you implement the multiband filter required here. It uses filtfilt.

Plus de réponses (0)


En savoir plus sur Measurements and Spatial Audio dans Help Center et File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by