| 摘要 |
A method and apparatus for generating control voltage signals in a surround sound processor is disclosed which utilizes a one-shot monostable multivibrator for minimizing intermodulation distortion while following rapid directional changes, yet minimizing intermodulation distortion. The apparatus includes a circuit for smoothing the directional information signals derived from audio input signals each with a continuously variable time constant to generate a corresponding control voltage signal, such that each time constant depends inversely upon the magnitude of the difference between the directional information signal applied thereto and the corresponding control voltage signal generated thereby. A one-shot circuit temporarily reduces the value of the continuously variable time constant associated with each smoothing circuit to a predetermined minimum value for a short, predetermined time period so that each of the corresponding control voltage signals rapidly approaches the value of its corresponding directional information signal within this time period, the one-shot being activated when the difference between any one of the directional information signals and its corresponding control voltage signal exceeds a predetermined threshold value. Other improvements are incorporated in the surround sound processor to optimize its performance.
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