Abstract: A stereophonic loudspeaker system which includes at least two channel loudspeakers and a centrally located feedback control loudspeaker. Each channel loudspeaker incorporates an electrically driven low frequency electrosonic transducer and a sonically driven electrosonic transducer sonically coupled together to form a sonic oscillator. The sonically driven transducer responds to sound and sonic vibrations produced by the electrically driven transducer to produce sounds and an electrical output signal. The feedback control amplifier includes a plurality of electrosonic transducers interconnected sonically and electrically. The transducers of the feedback control loudspeaker respond to the electrical signals from the sonically driven transducers of the channel loudspeakers to interactively enhance the production of aurally pleasing low frequency sound from the loudspeaker system.