From separating 4 signals to separating 2 signals - Matlab code

I have Matlab code used to separate four artificial signals (sawtooth, square, sine and cosine waves), named as 4-code. I want to use the same code to do the same thing but for 2 speech signals. I have actually tried to replicate what is in 4-code, and my code is named as 2-code. However, there is the Whitening/Centering processing that is added on my code (2-code) and which is not in the 4-code. My main problem is that I am not able to replicate the "Maximal Element of abs(W.A)" graph represented as figure(4) in 4-code and figure(1) in 2-code. I am simply missing a simple thing, perhaps mistake in one line and need help figuring it out. I am out of patient now. I have also attached the two speech signals to be used. (My budget is $25). Thank you.