Abstract: A speaker driver circuit for use in association with a source of audio signals and a single coil driven speaker, for communicating said signals to the speaker and for reducing unwanted noise in the speaker, and having a first coil connected between the output of the audio signal source and the input of the speaker, a second coil, connected between the speaker and the ground of the audio signal source, the second coil being bifilar wound with the first coil, so that signals passing through the first coil, and through the speaker and then through the second coil will substantially reduce unwanted noise in the speaker, and first and second capacitors connected between the first coil, and the second coil.