Yes they characterized them even down to manufacturer/production run using a complex waveform that allowed them to measure and tune the coefficients of their al

Yes they characterized them even down to manufacturer/production run using a complex waveform that allowed them to measure and tune the coefficients of their algorithm to match. Although there was also a little sound bite dropped in there that chips made on the same day on the same line did not match up. So it seems they have gotten everything close enough that they are within the manufacturing tolerances. And they did it all as if these differences are even audible to a human being.