Multi-channel audio system having a shared current sense element for estimating individual speaker impedances

摘要

A programmed data processor receives input voltage measurements for a number of speaker drivers, wherein each of the voltage measurements may be a sensed or estimated sequence of time-domain samples of a respective speaker driver input voltage that is over a different time frame. The processor obtains a sensed shared current, being a measure of current in a single power supply rail that is feeding power to each of a number of audio amplifiers, while the audio amplifiers are driving the speaker drivers in accordance with a number of audio channel signals, respectively. The processor computes an estimate of electrical input impedance for each of the speaker drivers using the sensed shared current and the input voltage measurements. Other embodiments are also described and claimed.

主权项

1. A method for operating an audio system having a plurality of speaker drivers, comprising:
providing a plurality of audio channel signals simultaneously to inputs of a plurality of audio amplifiers, respectively, while each of the audio amplifiers is driving its respective speaker driver; sensing current of a single power supply rail that is feeding power to each of the plurality of audio amplifiers, while each of the amplifiers is driving its respective speaker driver, to produce a sensed shared current; obtaining a measure of input voltage of each of the speaker drivers; and computing an estimate of electrical input impedance of each of the speaker drivers using the sensed shared current and the measures of input voltage.