| Re: REW repeatability.
One of the characteristics of the log sweep measurement technique is that harmonics are easily rejected, REW excludes them from the displayed frequency response. You can get a feel for how much the harmonic distortion content is increasing by looking at the portion of the impulse response that lies before the main peak (i.e. at times < 0), the harmonics appear as scaled down versions of the main impulse response. You can also use the percentage 2nd and 3rd harmonic displays on the SPL meter when playing sine wave test tones with the signal generator.
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