I have a set of transfer functions obtained by impacting an instrumentation hammer against a mass, measuring the acceleration on a set of accelerometers; the result is shown below. I want to get a curve to generalize the behavior of the system, in magnitude it is as simple as averaging the magnitude of the signals, however I wonder how can I treat the phase since by just calculating the angle of the mean per frequency the resulting curve is meaningless (which is explained in Phonon's answer).
With this in mind, is there a way to go? Additionally, I am working straight with the frequency domain signals of the measurement (calculated by the device); would this be solved by switching instead to the original time series --> averaging --> transforming manually to frequency?
Thanks in advance.