Sound reproduction system with driven and undriven speakers and motional feedback

Claim 1

In a sound reproduction system comprising an audio signal source, an amplifier for said audio signal source functionally connected with said source, an acoustical output transducer enclosure containing a plurality of acoustical output transducers, the improvement which comprises a system for negative feedback to said amplifier, said system comprising a driving acoustical output transducer responsive to an output of said amplifier and a driven acoustical output transducer responsive to physical vibration of said driving acoustical output transducer, with both driving and driven speakers having motional sensors functionally attached thereto, a first motional sensor functionally attached to said driving acoustical output transducer, a second motional sensor functionally attached to said driven acoustical output transducer, said motional sensors providing electrical signals proportional (to the acoustical power and a motional functions of the acoustical output transducer) to a function of said transducer, said function selected from the class consisting of acoustical power and acoustical intensity which are motional functions of the acoustical output transducers to which they are connected, means for combining said electrical signals and means for employing said combined signals said signals being used as a source of said negative feedback.