QUATRE DISPERSION

APPARATUS AND INSTRUMENTS FOR PROCESSING, REPRODUCING, TRANSMITTING AND RECORDING SOUND OR IMAGES, NAMELY, LOUDSPEAKERS, STEREO COMPONENT SYSTEMS COMPRISING LOUDSPEAKERS, WOOFERS, AND STEREO AMPLIFIERS, AUDIO AND VIDEO SOUND AMPLIFIERS, RECORDERS AND PLAYERS OF OPTICAL DISCS, RECORDERS AND PLAYERS OF MAGNETIC TAPES, AUDIO MIXERS AND SIGNAL PROCESSORS