Abstract: The two channel audio surround sound circuit with automatic level control includes a right amplifier, a left amplifier, a right automatic level control and a left automatic level control. A right input is coupled to a positive input of the left amplifier through the right automatic gain control. The right input is coupled to a negative input of the right amplifier and coupled to the output of the right amplifier with one resistor. A left input is coupled to a positive input of the right amplifier through the left automatic gain control. The left input is coupled to a negative input of the left amplifier and coupled to the output of the left amplifier with another resistor.

Abstract: A personal listening device used in connection with the amplification of signals for enhancing the perceived quality and ambiance of sound heard by listener using stereo headphones or small speaker systems utilizes a difference signal that is cross-fed between stereo channels. The invention provides a perception of spatial presence in music sound when used with either stereo headphones or small speaker systems. The circuitry, wiring and packaging provide for multiple output jacks allowing for convenient sharing of the enhanced output signal from a personal listening device with other persons using headphones. The invention provides effects similar to stereo enhancement, surround sound, and psychoacoustic imagery in a small, inexpensive package for enhancing a user's audio experience.

Abstract: A two channel surround sound audio circuit (surround sound circuit) includes a first amplifier, a second amplifier, two polarized input capacitors, and two polarized output capacitors. A first input line is coupled through one polarized input capacitor to a positive terminal of the second amplifier and to a negative terminal of the first amplifier. A second input line is coupled through the other polarized input capacitor to a positive terminal of the first amplifier and to a negative terminal of the second amplifier. The output of the first and second amplifier are connected to the first and second polarized output capacitors, respectively. A second embodiment of the surround sound circuit includes two amplifiers, two inverting amplifiers, and two balancing potentiometers. The output of a single amplifier is balanced with the output of a single inverting amplifier with a single balancing potentiometer.

Abstract: A surround sound converter for home audio systems includes outputs for a left front speaker, a right front speaker, a left rear speaker, a right rear speaker, and an auxiliary output to accommodate a rear auxiliary amplifier. The surround sound converter also includes an input for the left and right channel speaker output of an amplifier, a receiver, or any stereo signal device which has an audio amplifier. At least one potentiometer controls the volume balance between the front and rear speakers. A left and right capacitor are used to drive the left and right rear speakers, respectively. An auxiliary output is provided to accommodate adding a rear auxiliary amplifier. A surround sound converter for vehicle audio systems utilizes an automotive stereo. A left front speaker and right front speaker are connected to the normal speaker outputs of the automotive stereo. The left rear speaker is connected to the left rear signal negative and the right rear signal negative.

Abstract: A surround sound converter for home audio systems includes outputs for a left front speaker, a right front speaker, a left rear speaker, a right rear speaker, and an auxiliary output to accommodate a rear auxiliary amplifier. The surround sound converter also includes an input for the left and right channel speaker output of an amplifier, a receiver, or any stereo signal device which has an audio amplifier. At least one potentiometer controls the volume balance between the front and rear speakers. A left and right capacitor are used to drive the left and right rear speakers, respectively. An auxiliary output is provided to accommodate adding a rear auxiliary amplifier. A surround sound converter for vehicle audio systems utilizes an automotive stereo. A left front speaker and right front speaker are connected to the normal speaker outputs of the automotive stereo. The left rear speaker is connected to the left rear signal negative and the right rear signal negative.

Abstract: A surround sound processor unit includes a plurality of preamplifiers, an in-phase audio decoder circuit, an out-of-phase audio decoder circuit, at least one transmitter, at least one receiver, at least one speaker amplifier, and a plurality of power amplifiers. A surround sound processor unit can take the stereo audio signal from a stereo VCR, a stereo receiver, a headphone jack, a stereo TV, or a car stereo to produce a three dimensional sound field. The left audio signal is amplified and outputed to a left front speaker. The right audio signal is amplified and outputed to a right front speaker. The in-phase audio decoding is accomplished by preamplifying the left and right audio signal, and connecting the output of the left and right preamplifiers to a singular input of a power amplifier. The output of the power amplifier drives a center channel speaker.

Abstract: A surround sound processor system includes an in-phase decoder circuit, an out-of-phase decoder circuit, and a plurality of audio amplifiers. In a wireless embodiment, the surround sound processor system also includes a plurality of FM transmitters and a plurality of FM receivers. A surround sound process system can take the stereo audio signal from a stereo VCR, a stereo receiver, a car stereo, or a stereo TV to produce a three dimensional sound field. A left audio signal and a right audio signal are input into an in-phase decoder, the in-phase audio signals are extracted from the left and right audio signals while the out-of-phase audio signals are canceled. The in-phase audio signals are sent to an audio amplifier and then to at least one center speaker. A left audio signal and a right audio signal are input into an out-of-phase decoder, the out-of-phase audio signals are extracted from the left and right audio signals while the in-phase audio signals are canceled.