Patent ID: 9674593
Date: 2017-06-06
CPC Classifications: H04R

Claim:
1. A loudspeaker controller for controlling a loudspeaker driven by an input signal, the loudspeaker controller comprising: an amplifier to amplify the input signal; a measurement signal generator configured to generate a measurement signal; a mixer arranged prior to the amplifier to introduce the measurement signal into the input signal, the loudspeaker controller configured to determine time-varying impedance information of the loudspeaker based on the loudspeaker voltage, voicecoil inductance of the loudspeaker, and a measure of the loudspeaker current and provide for control of the loudspeaker in accordance with said time-varying impedance information, wherein the impedance of the loudspeaker varies with instantaneous displacement, wherein the controller compares the time-varying impedance information with predetermined bounds to determine the loudspeaker's relation to an excursion limit, and wherein the loudspeaker controller controls the input signal as a function of the time-varying impedance information.