kris2014, either you are missing the point here, or maybe I am.
In my understanding, the whole approach here is a differential measurement, i.e. you compare one cable with another one and look at the difference of the signal only. If there is no difference when comparing some stupid "high end" cable with a standard one, you have proven that the "high end" claim is bollocks.
As I have tried twice to explain in the above posts, you can run this comparison with any old signal, and hence any old signal source. If there is noise in the signal, the two signal paths will both faithfully transmit the same noise, and it will cancel out at the output (with high precision).
Anway, I have tried to expain this threee times now. If this still makes no sense, I better let someone else have a try.