The method for calculating harmonic distortion

When computing harmonic distortion using this method, the basis is an impulse response measured using a sine sweep (exponential). The last part of this impulse response contains the harmonic distortion components if  was checked in Measurement->Settings… when the measurement was performed.

Note: The WinMLS distortion detection depends on the position of the time window lower limit. If your measurement does not have a large delay, the time window lower limit can be set to 0 milliseconds. If your measurement has a delay (> 1 millisecond), you can set the time limit manually or set it automatically using  the  feature in Plot->Plot Type Settings->Time Window….

Note: If the time window upper limit is set to a value higher than half the length of the impulse response, it is automatically reduced to the half length of the impulse response. This is to avoid the distortion part when calculating the frequency response.