An electronic device which filters and selectively amplifies frequencies, separating the frequencies into sections or bands, and routing them to outputs designed to drive power amplifiers and in turn, speakers. The frequencies filtered depend on the electrical value of the component parts in the circuits of the device, but not on the source or load impedances connected to the device, except in the case where the crossover is actually a passive crossover designed for insertion in the medium-level signal lines of an audio system rather than in speaker lines.