Plot Type Settings: Phase Frequency Response/Function...
Displays the dialog box shown below.
Note that the phase is influenced by the sound card response. This may be removed by using the measurement system correction feature. Most sound cards have a delay of some samples that give a linear phase shift. It is possible to remove a pure delay by using the delay removal and subtraction features of this dialog box.
The microphone will also influence the phase, to get an accurate phase, use a precision microphone with as high a bandwidth (higher than the measurement frequency range) and flat frequency response as possible.
General Frequency Domain Settings