Methods and apparatus related to protection of a speaker

A method, comprising:

• calculating, at a calibration temperature of a speaker, a calibration parameter through a coil of the speaker in response to a first test signal;
• sending a second test signal through the coil of the speaker;
• measuring a parameter through the coil of the speaker based on the second test signal;
• and
• calculating a temperature change of the coil of the speaker based on the parameter and based on the calibration parameter at the calibration temperature.

A method, comprising:

• receiving an indicator of an amplitude of an audio signal associated with a speaker;
• determining that the amplitude exceeds a threshold amplitude value;
• modifying, for a time period, a time constant of an input filter from a first value to a second value in response to the determining;
• and
• modifying the time constant from the second value to a third value in response to the time period expiring.