Frequency-domain signal processing of pressure sensor signals and/or flow signals is used to provide on-demand control of a multi-component fluidic system. An example method, implemented in a phacoemulsification system comprises receiving a signal from each of one or more sensors, the one or more sensors comprising at least one pressure sensor, and converting each of one or more of the received signals, including at least one signal from a pressure sensor, to a frequency-domain representation of the received signal. The method further comprises identifying, based on the frequency-domain representations of received signals, at least one event from a set of predetermined events, and controlling one or more fluid control devices, responsive to the identifying.