Arbitration adjustment for acoustic reproduction systems

摘要

An acoustic production system having multiple signal sources and a power amplifier driving an acoustic transducer such as a loudspeaker includes an arbitrator in a power limiter circuit to selectively limit the input level of one of the sources to the power amp in response to an overdrive signal from the amplifier. The input level to the power amplifier is automatically reduced in response to the overdrive signal until a predetermined level of limiting has been attained. Once the predetermined level of limiting is reached, the arbitrator outputs a second overdrive signal to prompt additional limiting of the power amplifier output. Preferably, the arbitrator is included in an interior active noise cancellation module combined with an audio entertainment system for a passenger compartment of a motor vehicle. The audio system also preferably separates the audio reproduction into high frequency and low frequency branches, whereby the arbitrator acts upon the signals output in the frequency ranges of active noise cancellation and the bass output of the audio entertainment system that are most likely to overdrive an amplifier.