An audio amplifier apparatus includes an audio amplifier which receives a single audio signal and produces a plus phase audio signal and a minus phase audio signal, both dependent upon the single audio signal. The plus phase audio signal and minus phase audio signal are received by first and second inputs of a speaker, respectively. A current sensing circuit senses a level of current received by the first or second inputs of the speaker and outputs a current sensing signal dependent upon the sensed level of current. An amplifying circuit receives and amplifies the current sensing signal. A mixer circuit receives the amplified current sensing signal and an audio drive signal and produces the single audio signal dependent upon the amplified current sensing signal and the audio drive signal. The single audio signal is produced at a node in-between two resistors.