I'm using spectrumMeas() function inside Viva calculator for evaluating THD, THD+N performance of Class-D amplifier outputs.
I saw different measured results coming out of different windowing used and the help information of the function doesn't tell any more detailed equations behind it.
I want to know how the function deal with windowing function. for example, how it deal with additional bins caused by the windowing and how to apply scaling on signal, noise and harmonic bins.
Personally I don't have time at the moment to research this, so I would suggest if you want an answer quickly, you should contact customer support.