| 摘要 |
A signal regulator regulates an auxiliary signal based upon a primary signal scaled by an external amplifier. The signal regulator receives the primary signal with an unscaled level. Processing circuitry monitors the unscaled level of the primary signal. The primary signal is then output to the external amplifier for scaling, either by amplification or attenuation. The primary signal with a scaled level is in turn received by the signal regulator from the amplifier. The processing circuitry monitors the scaled level of the primary signal from the amplifier, and then generates a gain factor based upon the unscaled level and the scaled level of the primary signal. An auxiliary signal is received by the signal regulator. Adjusting circuitry receives the gain factor from the processing circuitry and adjusts a level of the auxiliary signal based upon the gain factor. The auxiliary signal with the adjusted level is then provided to an external component, for example, a loudspeaker. The signal regulator is particularly useful in regulating the volume of auxiliary audio channels in a surround-sound system based upon the volume of the main or front channels amplified by an audio/video receiver. The signal regulator performs system delay measurements, phase synchronization of the unscaled and scaled primary signals, volume tracking, and consecutive cross-correlation measurements to safe guard against erroneous volume adjustment. |
