Monitoring systems with predictive failure analysis technology (e.g., Self Monitoring Analysis and Reporting Technology (S.M.A.R.T)) operate on the basis of correlations between the hard disk's mechanical and electronic characteristics. Using wavelet transforms to analyze electrical signals from the hard disks can help better determine changes in values and trends in various hard disk characteristics. Using wavelet transforms allows for thorough and deeper analysis of the electrical signals from the hard disks. Wavelet analysis can be performed on the electrical signal to extract time and frequency information associated with the low and high frequency components. Analyzing the extracted components of the electrical signal can indicate a presence and position of one or more mechanical defects on the hard disk.