Sound reproducing apparatus

Claim 1

IN A SYSTEM FOR RADIATING SOUND ENERGY, FIRST VIBRATORY MEANS FOR PROPAGATING SOUND ENERGY AND MEANS FOR COUPLING THE SAME TO AN ACTUATING SOURCE, SECOND VIBRATORY MEANS, AN ENCLOSURE HAVING APERTURED WALL PORTIONS TO WHICH BOTH OF SAID VIBRATORY MEANS ARE MOUNTED SO THAT ONE SURFACE OF EACH OF SAID VIBRATORY MEANS IS CONTACTED BY THE ATMOSPHERE OUTSIDE OF SAID ENCLOSURE AND THE VIBRATORY MEANS ARE ACOUSTICALLY COUPLED TO ONE ANOTHER WITHIN THE ENCLOSURE BY MEANS OF THE AIR VOLUME CONTAINED WITHIN THE ENCLOSURE, EACH OF SAID VIBRATORY MEANS BEING CHARACTERIZED BY A GREE AIR VIBRATORY RESONANCE FREQUENCY SUBSTANTIALLY LOWER THAN A RESONANCE FREQUENCY RANGE OF SAID VIBRATORY MEANS MOUNTED IN THE ENCLOSURE, AND VELOCITY, RESPONSIVE DAMPING MEANS ELECTROMECHANICALLY COUPLED TO SAID SECOND VIBRATORY MEANS FOR DAMPING THE AMPLITUDE EXCURSIONS OF SAID FIRST VIBRATORY MEANS BY SELECTIVELY ABSORBING THE SOUND ENERGY THEREFROM, SAID VELOCITY RESPONSIVE DAMPING MEANS INCLUDING MEANS FOR SELECTIVELY VARYING WITHIN LIMITS THE RELATIVE PHASE RELATION BETWEEN THE MOTIONS OF SAID FIRST AND SECOND VIBRATORY MEANS.