A method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including obtaining original data based on samples of a vibration signal; converting the original data to an analytical signal having a real component and an imaginary component; determining complex magnitudes of the analytical signal; processing the complex magnitudes of the analytical signal to produce a frequency-domain signal; and determining complex magnitudes of the frequency-domain signal to generate a shock spectrum.