One embodiment of the invention provides a detection system. The detection system includes an analog to digital converter that converts one or more analog vibration signals into one or more digital samples, a filter that analyzes at least a portion of the one or more digital samples and identifies energy values across a range of frequencies, a frequency selector that selects a subset of the frequencies for analysis according to one or more operational characteristics, and an analyzer that analyzes the subset of frequencies along with threshold values to identify one or more results.