Question

confused need help! Matlab

Answer 1

What do you need help with?

Answer 2

What is going on here? What do I need to do?

Answer 3

My understand is that we have a z matrix with two channels and we have three bands ( low middle, and high)

Answer 4

let me think about this for a bit. I think I have come up with a solution or at least an idea.

Answer 5

go to computer science section to get helped

Answer 6

@jim_thompson5910

Answer 7

how does filter() work? filter(a, b, x) a being a row, b being a column, x being the name of the matrix?

Answer 8

clear, clc, close all % clears all windows

% loads rdd file into matlab
[z, fs] = audioread('rdd.wav');

% loads filter coeffs data
load('filter_coeffs');

% band 1 is lpf low frequences
% band 2 is the bpf mid-range frequences
% band 3 is the hpf high frequences

% z matrix contains 2 channels sound sample vs time (left channel col1 and right channel col2)

% small if else statement off to side
S = input('Do you want to activate sound, yes/no ');

if (S == 1); % one being yes
sound(z, fs)
fprintf('You chose yes \n');

else (S == 0); % zero being no

fprintf('You chose no \n');
end

band1 = lpf; % storing low power frequency in band1
band2 = bpf; % storing mid-range power frequency in band2
band3 = hpf; % storing high power frequency in band3
chan1 = z(:,1); % 1 for left of z matrix
chan2 = z(:,2); % 2 for right of z matrix

% asking user which channel to use 1 or 2
chan = input('Enter channel: ');

if (chan == 1)

chan1 = z(:,1);

fprintf('you chose channel 1 \n'); % right channel selected

elseif (chan == 2)

chan2 = z(:,2);
fprintf('you chose channel 2 \n'); % left channel selected
end

% asking user which bands would like to be used
ban = input('Enter a band: ');

if (ban == 1)

band1 = filter(

Answer 9

I have no idea how `filter` works. Even after reading through this page

http://www.mathworks.com/help/matlab/ref/filter.html

it still makes no sense to me. But the page may help you.

Answer 10

This is the same page I looked over myself. Let me review it over again.

Answer 11

@jim_thompson5910 do you understand this?

http://www.mathworks.com/help/matlab/data_analysis/filtering-data.html

Answer 12

So I'm guessing the point of this lab is to take audio in and somehow modify it to make it sound better?

Answer 13

Yeah I think. My understanding was you can select from two different channels then also select a variety of different bands to make the audio sound different

Answer 14

In the link I just posted. So b represents a 1x4 matrix with 1/4 in each induce. so the original is being reduced by a quarter?

I have three different bands here band1, band2, and band3. I need to make a prompt asking the user which bands I would like to use with the corresponding channels 1 and 2?

Answer 15

I'm not 100% familiar with audio terms but this page is saying
A = feedback coefficients
B = feedforward coefficients

https://www.cs.sfu.ca/~tamaras/filters/Matlab_s_filter_function.html

Answer 16

I'm not exactly sure how the bands you pick help set up the coefficients which are used for filtering. I have a feeling it's where you say "what is the loudest you're willing to hear?" then they define a decibel value. That's a complete guess though. I'm far from an audio engineer. You might be better off in the CS section.

Answer 17

Okay. This is more electrical engineering, something I am not too familiar with myself.

Answer 18

I will post in CS section