Audio control system
AssigneeThe Magnavox Company
InventorPaul Filliman
Life of this patent
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Abstract
An audio control system for altering the frequency content of an audio signal with a d.c. control voltage. An audio signal is divided into a plurality of signal channels representing different portions of the audio signal frequency spectrum. Each signal channel is terminated by an attenuator which is responsive to a d.c. control voltage. The attenuated signals are then combined. By changing a d.c. control voltage a change in tone, volume, balance or loudness of an audio signal in a stereoamplifier or the like may be achieved.
Claims8
An audio control apparatus for controlling a signal comprising:
- a. a plurality of frequency selective filters, said filters having a common input for receiving an audio signal;
- b. a plurality of differential amplifiers for receiving said filter output signals each of said differential amplifiers providing biphase signal currents in response to an input voltage;
- c. a plurality of attenuators for controlling said biphase signal currents produced by each of said differential amplifiers, said attenuators having a selectable attenuation level;
- and
- d. means for combining said attenuator output signals to form a composite signal, said composite signal having a frequency spectrum dependent upon the relative attenuation levels provided by said attenuators.
An apparatus for controlling an audio signal comprising:
- a. means for dividing said signal into a plurality of biphase signals having different frequency spectri;
- b. a plurality of quadrature attenuators for selectively varying the amplitude of each of said biphase signals representing different frequency spectri;
- and
- c. means for combining said quadrature attenuator output signals whereby a composite signal is formed having a frequency spectrum dependent upon the relative attenuation levels provided by said attenuators.
An apparatus for controlling the frequency content of an audio signal comprising:
- a. means for dividing an audio signal into first and second signals having different frequency spectri;
- b. a first attenuator means for receiving said first signal of said means for dividing, said attenuator means having a selectable attenuation level;
- c. a second attenuator means for receiving said second signal of said means for dividing, said attenuator means having a selectableattenuation level;
- and
- d. a means for combining said audio signal with said first and second attenuator means output signals to produce a third signal having a frequency spectrum which is controllable by selectively varying the attenuation level of said attenuators.
An apparatus for controlling the frequency content of an audio signal comprising:
- a. a first filter means for removing the low frequency content of said audio signal;
- b. a second filter means for removing the high frequency content of said audio signal;
- c. a first attenuator for selectively controlling the amplitude of said first filter means output signal;
- d. a second attenuator for selectively controlling the amplitude of said second filter means output signal;
- e. a bandpass filter for simultaneously removing the high and low frequency components of said audio signal;
- and
- f. signal combining means for combining the outputs of said first attenuator, said second attenuator, and said bandpass filter whereby a composite signal is formed having a selectable frequency spectrum dependent upon the amplitude of said first and second attenuator output signals.
An apparatus for controlling an audio signal comprising:
- a. means for dividing an audio signal into first biphase signal currents, second biphase signal currents, and third biphase signal currents, each of said biphase signal currents representing a different portion of said audio signal frequency spectrum;
- b. a first attenuator for receiving said first biphase signal currents, said attenuator having a selectable attenuation level for controlling the amplitude of said biphase signal currents;
- c. a second attenuator for receiving said second biphase signal currents, said attenuator having a selectable attenuation level for controlling the amplitude of said biphase currents;
- d. means for combining said third biphase signal currents with said first and second attenuator output signals to produce fourth biphase signal currents;
- and
- e. means for converting said fourth biphase signal currents into a single phase signal voltage, said signal voltage having a frequency spectrum dependent upon the relative attenuation provided by said attenuators.
Dependencies are inferred from the claim text.