An inertially balanced miniature passive radiator full-range loudspeaker system is disclosed. In one embodiment the speaker system is a two-way system with low and high frequency components, where the low-frequency component is comprised of one active transducer and two passive radiators and the frequency range for this component is not outside of 10 Hz to 500 Hz. The low and high frequency components are individually optimized for operation in low and high frequency ranges respectively. By placing the passive radiators on opposing sides of an enclosure of the speaker system, the momentum generated by the motion of each of the passive radiators substantially cancels when the passive radiators are in phase. A passive radiators may be fitted with a voice-coil electrically connected to a corresponding voice-coil on the other passive radiator in a pair such that the generated back EMF resists out of phase motion of the passive radiators.