Abstract: A compact noise suppression circuit for a small speaker system and having a circuit board with a left signal input connection and a right signal input connection and a ground connection, and further having a left speaker supply connection and a left speaker return connection, and a right speaker supply connection and a right speaker return connection, and further having a left bifilar coil and a right bifilar coil, and left and right coil connections on the circuit board, and means securing said left and right bifilar coils to respective coil connections on the circuit board. Also disclosed is a compact portable audio player system incorporating such a noise suppression circuit, and a noise suppression circuit for a mon-aural signal system.

Abstract: A compact noise suppression circuit for a small speaker system and having a circuit board with a left signal input connection and a right signal input connection and a ground connection, and further having a left speaker supply connection and a left speaker return connection, and a right speaker supply connection and a right speaker return connection, and further having a left bifilar coil and a right bifilar coil, and left and right coil connections on the circuit board, and means securing said left and right bifilar coils to respective coil connections on the circuit board.

Abstract: A single speaker driver circuit having, a low frequency input coil connected between an audio circuit output and the input of the speaker, a low frequency return coil, connected between the return of the speaker and the return of the audio signal, the low frequency return coil being bifilar wound with the low frequency input coil, and a higher frequency input coil connected between the audio circuit output and the return of the audio circuit, and a secondary coil connected between the input of the speaker, and ground, the higher frequency input coil and the secondary coil being bifilar wound with one another.

Abstract: A damping circuit for speaker systems of the type containing at least one speaker having a speaker coil with an input and an output connection and having a matching coil adapted to be connected in series with the input connection of the speaker coil and a damping coil adapted to be connected in series with the output connection of the speaker coil, the matching and damping coils each having respective input and output ends, and being wound together in the same rotational direction with their respective input ends together and their respective output ends together in a method having a unity coefficient of coupling so that the primary signal current flows through both coils in the same direction, whereby electro-magnetic fields induced around the matching and damping coils interact with one another during passage of signals and damp out signal distortions due to induced transient signals in the matching coil and to reduce signal distortions due to induced transient signals in the speaker coil.

Abstract: A damping circuit for speaker systems of the type containing at least one speaker having a speaker coil with an input and an output connection and having a matching coil adapted to be connected in series with the input connection of the speaker coil and a damping coil adapted to be connected in series with the output connection of the speaker coil, the matching and damping coils each having respective input and output ends, and being wound together in the same rotational direction with their respective input ends together and their respective output ends together in a method having a unity coefficient of coupling so that the primary signal current flows through both coils in the same direction, whereby electro-magnetic fields induced around the matching and damping coils interact with one another during passage of signals and damp out signal distortions due to induced transient signals in the matching coil and to reduce signal distortions due to induced transient signals in the speaker coil.