Abstract: A signal processing distortion reducing system which includes a plurality of series connected, straight, conductive signal path sections. These sections direct the flow of signal currents into a series of sharp 90 degree turns, which minimizes electromagnetic coupling between adjacent conductive signal path sections. These 90 degree turns have a distortion reducing, collimating effect on electromagnetic signals. Variations in construction include machined squares and bent strips of sheet material.

Abstract: A pair of amplifiers are coupled to respective loudspeakers. The output terminals of the amplifiers are coupled to each other through a filter network for reducing the effects of time delayed acoustic feedback from the ambient surroundings and from the other displaced loudspeaker on the amplifiers.

Abstract: A loudspeaker includes a pole piece that is transversely divided into magnetically coupled, but electrically isolated first and second sections. The first pole piece section is surrounded by the voice coil and is magnetically coupled to, but electrically isolated from, the loudspeaker bottom plate. Other versions include pairs of loudspeakers with reversed polarity magnets and magnetic intercoupling for offsetting distortion produced therein.

Abstract: A loudspeaker includes a radially slotted ceramic permanent magnet for reducing distortion. Other constructions include slotted top and bottom plates and radially slotted bucking magnets, in combination with slotted magnet loudspeakers. The slotted bucking magnets may be retrofitted to conventional loudspeakers.

Abstract: A speaker system includes crossover networks connected to a low output impedance amplifier through RF chokes. The individual outputs of the crossover networks are connected by separate wires to each of the individual speakers. RF reducing capacitors are connected across the terminals of each speaker and across the output terminals of the crossover networks. Separate back EMF resistors are connected across the speakers for dissipating back EMF signal energy. The component values in each of the crossover networks are split and balanced to present a substantially identical electrical configuration to both polarities of signal.

Abstract: A high quality amplifier includes energy dissipating resistors coupled across reactive components which are subject to shock excitation by audio signals, thus giving rise to time displacement distortion. The range of resistor values is from 5K to 100K with a preferred range being from 10K to 50K ohms. The power transformer has each winding shunted by an energy dissipating resistor chosen to produce a current draw of between 1 and 5 milliamperes.

Abstract: An expander circuit for expanding stereo signals comprises left and right channel variable gain stages whose gain varies in proportion to the amplitude of the control signals fed to the control inputs thereof; and left and right channel expansion control signal providing means for receiving respectively at least portions of the left and right channel signals and feeding expansion control signals to the control inputs of the variable gain stages. These control signals have amplitudes directly proportional to the amplitudes of the signals fed to the inputs of the expansion control signal providing means. The improvement in the circuit is the addition of a signal coupling network for coupling a portion of the left-right channel stereo image producing signal components to the input of the associated expansion control signal providing means and a much smaller porportion thereof to the expansion control signal providing means associated with the other channel.

Abstract: A power supply for generating polarizing voltages for the drivers on an electrostatic speaker system includes a charging circuit which charges a battery from the applied audio signal. A dc-to-dc converter generates the relatively high polarizing voltages from the battery voltage and it includes an oscillator which generates an alternating voltage to a voltage multiplier circuit. An electronic switch circuit turns the oscillator on when an audio signal is present and turns it off a preselected time interval after the audio signal is removed.

Abstract: A noise reduction circuit for uncompressed and randomly compressed audio signals comprises a variable gain stage providing a gain which varies with the magnitude of a DC control signal fed to a control terminal thereby, an AC to DC converter for generating a DC signal proportional to the amplitude of the AC signal fed thereto and a filter for passing middle and upper frequencies and for eliminating or substantially reducing the low frequencies fed thereto and coupled between the audio signal input and the input to said AC to DC converter.