Stereophonic sound system particularly useful in a cinema auditorium
A network is described which processes two channel stereophonic sound programs for playback through left, right and center sound reproduction channels. Use of the network allows certain advantages of a three channel program to be obtained from the two channel program. The network delays the left and right channels to give precedence to the center channel information but reduces the level of this information to enable the left and right channels to establish a stereo image.
Publication number: US4074083A | Search similar patents
Stereo signal reproducing system
A system for reproducing stereophonic signal to create a stereophonic sound image in front of each of listeners sitting side by side in a compartment. The system includes a first loudspeaker positioned relative to the right of the first listener sitting on the right, a second side loudspeaker positioned relative to the left of the second listener sitting on the left, and a center loudspeaker unit positioned between the first and second side loudspeakers. A signal generator generates R and L stereophonic signals. The R signal is applied to drive the first side loudspeaker and the L signal is applied to drive the second side loudspeaker. The R and L signals are applied to drive the center loudspeaker unit. The signal generator includes a device for providing a predetermined time delay to the R and L signals applied to drive the center loudspeaker unit with respect to the signals applied to drive the first and second side loudspeakers.
Publication number: US4769843A | Search similar patents
Method and device for wireless stereophonic transmission from a sound reproducing apparatus to loudspeakers
Device intended for the stereophonic restoration of sound signals obtained from a sound reproducing apparatus, by acoustic chambers. It comprises a transmission unit (1) and at least two acoustic chambers (2), comprising an antenna (9), a high-frequency amplifier (10), a frequency synthesiser (11), which controls a demodulator (12), a decoder (13), a switch (14) permitting selection, depending on the chamber, of the signal corresponding to the channel intended to be reproduced, a low-frequency amplifier (15) and at least one loudspeaker (16).
Publication number: EP0091874A1 | Search similar patents
Stereophonic sound reproduction method and apparatus
Disclosed is a stereophonic sound reproduction method, which obtains a multi-channel audio signal, renders the obtained signal to a channel to be reproduced according to channel information and a frequency of the multi-channel audio signal, and mixes the rendered signals.
Publication number: WO2015060696A1 | Search similar patents
Two-channel, four loudspeaker-component enhanced sterophonic system
The present invention is an improved two-channel, four loudspeaker-component enhanced stereophonic system which includes a pair of front loudspeaker systems, a pair of rear loudspeaker systems and a pair of speaker enclosures into each of which one of the front loudspeaker systems and one of the rear loudspeaker systems are placed. The enhanced stereophonic system also includes two electronic matrix networks which interconnect the input terminals of each front loudspeaker system to the left and right channel amplifier output terminals, respectively, and which also interconnect the positive input terminal of each rear loudspeaker system to the left and right channel positive amplifier output terminals, respectively. The electronic matrix networks include a first high-pass filter and a second high-pass filter each of which has an input terminal and an output terminal. The input terminal of the first high-pass filter is interconnected to the left channel positive amplifier output terminal. The output terminal of the first high-pass filter is interconnected to the negative input terminal of the second rear loudspeaker system. The input terminal of the second high-pass filter is interconnected to the right channel positive amplifier output terminal. The output terminal of the second high-pass filter is interconnected to the negative input terminal of the first rear loudspeaker system. Each electronic matrix network also includes a resistive attenuation circuit whereby the output levels of the rear loudspeaker systems may be adjusted.
Publication number: US4369335A | Search similar patents
Stereophonic sound reproducing apparatus and stereophonic sound reproducing program
A stereophonic sound reproducing apparatus for realizing a surrounding system by means of a front speaker by performing a simple signal processing. A surround system (100) performs filtering of a surrounding signal conventionally to be converted into sound by a surround speaker by using an all-pass filter without using such a surround speaker, produces sound from the filtered surround signal from a front speaker placed in front of the listening position, and controls the sound image localization of the surround signal as if the sound from the surround signal were produced from a surround speaker placed beside or behind the listener.
Publication number: WO2007108301A1 | Search similar patents
Stereo signal reproducing system
A system for reproducing stereophonic signals to create a stereophonic sound image in front of each of listeners sitting side by side in a compartment. The system includes a right-hand loudspeaker positioned relative to the right of the first listener sitting on the right, a left-hand loudspeaker positioned relative to the left of the second listener sitting on the left, and a center loudspeaker positioned between the right- and left-hand loudspeakers. A signal generator generates R and L stereophonic signals. The R signal is applied to drive the right- and left-hand loudspeakers. The L signal is fed to drive the center loudspeaker. The signal generator includes a circuit for attenuating the R signal to the right-hand loudspeaker and a circuit for attenuating the R signal to the left-hand loudspeaker.
Publication number: US4703502A | Search similar patents
Tv receiver for the reproduction of stereophonic transmissions
1. A television receiver (1) for the reproduction of transmission with stereo sound, having at least one loudspeaker (3, 4) radiating forwards and at least one loudspeaker (5, 6) radiating sideways and having devices for the reception of stereo sound transmission by the two sound-carriers method, wherein the signal m(L+R) is transmitted on the first sound carrier and the signal m2R is transmitted on the second sound carrier, m being any numerical factor, and the stereophonic sum signal L+R, amplified in a first low-frequency amplifier (12), is fed to its one or more loudspeaker(s) (3, 4) radiating forwards and the stereophonic difference signal L-R is fed to its one or more loudspeaker(s) (5, 6) radiating sideways, characterised in that a single differential amplifier (7) is provided in the receiver, by means of which amplifier a difference signal m(L+R)-m2R=m(L-R) is obtained which is fed to a second low-frequency amplifier (13), and that the loudspeaker(s) (5, 6) radiating sideways, which is or are fed with the difference signal m(L-R), is or are disposed in the side walls of the receiver housing.
Publication number: EP0069864A3 | Search similar patents
An audio system is described for producing a plurality of surround-sound channels in response to an audio input signal, comprising a first stand-alone amplifier system (103) adapted to receive a left and right channel signal from a source and to output signal levels of said left and right channel signals to drive left and right channel loudspeakers (101, 102); a second amplifier system (111) including a surround-sound decoder (212) to split said audio input signal into said left and a right channel signal and into at least three surround-sound channels and an amplifier section to increase the signal levels of said at least three-surround channels to drive surround-sound channel loudspeakers and maintaining signal levels of said left and right channel signals at input levels for said first amplifier stage. Both amplifier systems are minimally linked and preferable volume-controlled through the stereo system.
Publication number: WO03061343A2 | Search similar patents
Post-amplification stereophonic to surround sound decoding circuit
A post-amplification stereophonic to surround sound decoding circuit is described herein. The decoding circuit includes inputs to be connected to a stereophonic power amplifier to receive a powered amplified stereophonic signal and outputs to be connected to left and right main loudspeakers, to left and right secondary loudspeakers and to a central loudspeaker. The decoding circuit includes secondary channels decoding circuit decoding left and right surround channel signals to be supplied to the left and right secondary loudspeakers, respectively, and a central channel decoding circuit decoding a central channel signal to be supplied to the central loudspeaker. The central channel decoding circuit includes two decoupling capacitors decoupling the left and right signals from the powered amplified stereophonic signal before combining these signals to yield the central channel signal. This decoupling action prevents 'bleeding' of the left and right signals that would degrade the stereophonic signal.
Publication number: WO9926455A1 | Search similar patents
Control circuit for a spatial stereo expander
A stereophonic audio processing system (20,26,24,28) having left and right stereophonic sound channels with respective loudspeakers therefor is presented. The system is provided with spatial expansion of the stereophonic sound so that a first pair of spaced-apart loudspeakers (30) will acoustically appear to be spaced further apart then they actually are. The audio system is provided with provisions (40) for connecting a second pair of loudspeakers which can be spatially located at a distance between the loudspeakers which is larger than the first pair of loudspeakers. The audio system is provided with apparatus for providing stereo sound without spatial expansion when such secondary loudspeakers are used.
Publication number: EP0584719A1 | Search similar patents
Sound field control device
In the sound field control device, main signals and a surround signal are generated on the basis of input left and right 2 channel signals, and 4 channel main sound field signals and 4 channel surround sound field signals which are respectively aggregations of reflected sound signals of various directions in the respective sound fields are generated on the basis of reflected sound parameters of sound fields established with respect to the main signals and the surround signal, and the 4 channel main sound field signals and the 4 channel surround sound field signals of each corresponding channel are combined together and provided as 4 channel sound field signals to be sounded. Reflected sounds are created on the basis of reflected sound parameters of a certain established sound field regardless of sound field components contained in a source signal and output as a sound field signal. By sounding the sound field signals by sound field control loudspeakers arranged about a listener, an effect that gives to the listener the impression that he is surrounded by the sound can be produced.
Publication number: US5261005A | Search similar patents
The invention relates to a loudspeaker arrangement inside a device for playing back stereophonic audio signals. The inventive loudspeaker arrangement consists of a housing located inside the device, a loudspeaker for bass signals, and of loudspeakers for mid-range and treble signals. Crossover networks divide the stereophonic audio signals for playback by the loudspeakers into bass signals, mid-range signals and treble signals. The crossover network have a crossover frequency that is higher than the cut-off frequency of the loudspeaker for bass signals.
Publication number: WO2004019655A1 | Search similar patents
Stereo enhancement system
The sound field in a stereo reproduction system is enhanced by a preprocessor that removes a portion of the audio information that is common or substantially common to both the left and right stereo input signals before processing the signals in left and right sound placement filters. The left and right placement filter output signals, from which a portion of the common audio information was previously removed before processing, are added to the right and left stereo input signals, respectively, to produce enhanced sound field stereo output signals. The input signals that do not undergo placement processing are delayed in delay filters so that coherency is maintained when the signals are added and both the placement filters and the delay filters can be implemented by a series of cascaded bi-quadratic filters.
Publication number: US5440638A | Search similar patents
Apparatus for improvement of stereophonic sound
An apparatus for improvement of stereophonic sound. A source (8) of stereophonic sound is provided with two internal loudspeakers (14,16) and external access (30,32) to the stereophonic signal. A "wall of sound" effect is achieved by coupling of the stereophonic signal to at least two external loudspeakers (18,20) with the internal loudspeakers being fed a mixture of the stereophonic signal at reduced power.
Publication number: EP0383535A3 | Search similar patents