Sound enhancement system

Abstract

The present invention provides an audio enhancement apparatus and method which spectrally shapes the differential information in a pair of audio signals so as to create an immersive, three-dimensional effect when the audio signals are acoustically reproduced. In a preferred embodiment, the invention includes a two-transistor amplifier which spectrally shapes the differential information with what are called cross-over networks. The cross-over networks spectrally shape the differential information by selectively emphasizing or de-emphasizing certain frequencies in the differential information. In addition, the preferred embodiment adjusts the level of the sound which is common to both input signals to reduce clipping.

What is claimed is:  
     
         1 . An audio enhancement system comprising: 
 an audio generator configured to output at least two audio signals;    a pair of circuits coupled to said audio generator, said pair of circuits are configured to distinguish common-mode information which is common to said audio signals from differential information which is not common to said audio signals; and    a first cross-over network in communication with said pair of circuits, said first cross-over network configured to emphasize a first set of frequencies in said differential information relative to a second set of frequencies in said differential information.    
     
     
         2 . The audio enhancement system of    claim 9    further comprising a second cross-over network in communication with said pair of circuits, said second cross-over network configured to modify a second set of frequencies in said differential information in a different manner than said first set of frequencies modified by said first cross-over network.  
     
     
         3 . A circuit comprising: 
 at least two inputs, each input configured to receive an input signal    two transistors, each of said transistors in communication with one of said inputs, said transistors configured to distinguish common-mode information which is common to said input signals from differential information which is not common to said input signals; and    spectral shaping circuitry coupled to said transistors, said spectral shaping circuitry configured to modify a first range of frequencies in said differential information in a different manner than a second range of frequencies in said differential information.    
     
     
         4 . The circuit of    claim 23    further comprising common-mode adjustment circuitry coupled to said transistors, said common-mode adjustment circuitry configured to variably modify the gain of said common-mode information.  
     
     
         5 . The circuit of    claim 23    further comprising differential adjustment circuitry coupled to said spectral shaping circuitry, said differential adjustment circuitry configured to variably alter said modification of said differential information.  
     
     
         6 . The circuit of    claim 23    wherein aid transistors output said common-mode information and said differential information with at least two output signals.  
     
     
         7 . The circuit of claim  26  further comprising at least two speakers connected to said output signals.  
     
     
         8 . The circuit of claim  26  further comprising sound processing circuitry connected to said output signals, said sound processing circuitry configured to further modify said output signals.  
     
     
         9 . The circuit of    claim 23    further comprising output buffer circuitry coupled to said transistors, said output buffer circuitry configured to isolate said transistors from a load placed on either of said output signals.  
     
     
         10 . A circuit comprising: 
 at least two input signals;    a means for distinguishing common-mode information in said input signals from differential information in said input signals; and    a means for spectrally shaping said differential information.    
     
     
         11 . The circuit of claim  30  wherein said means for distinguishing also combines said common-mode information and said spectrally shaped differential information to generate at least two output signals.  
     
     
         12 . The circuit of claim  31  further comprising a means for buffering said output signals.  
     
     
         13 . The circuit of claim  30  further comprising a means for variably adjusting said spectral shaping of said differential signal.  
     
     
         14 . The circuit of claim  30  wherein said means for distinguishing also modifies said common-mode information.  
     
     
         15 . The circuit of claim  34  further comprising a means for variably adjusting said modification of said common-mode information.  
     
     
         16 . A method of enhancing a pair of signals comprising the steps of: 
 receiving a pair of signals;    discerning with a pair of transistors common-mode information which is common to said audio signals and differential information which is not common to said audio signals;    spectrally shaping said differential information; and    combining with said transistors said spectrally shaped differential information with said common-mode information to generate at least two output signals.    
     
     
         17 . A method of enhancing audio information comprising the steps of: 
 directing at least two audio signals to a pair of transistors which distinguish common-mode information which is common to said audio signals from differential information which is not common to said audio signals; and    spectrally shaping said differential information with multiple cross-over networks which are in communication with said transistors.    
     
     
         18 . A circuit comprising: 
 at least two input signals;    a means for distinguishing common-mode information in said input signals from differential information in said input signals; and    a means for spectrally shaping said differential information, wherein said means for distinguishing also combines said common-mode information and said spectrally shaped differential information to generate at least two output signals.    
     
     
         19 . The circuit of claim  50  further comprising a means for buffering said output signals.  
     
     
         20 . A circuit comprising: 
 at least two input signals;    a means for distinguishing common-mode information in said input signals from differential information in said input signals; and    a means for spectrally shaping said differential information, wherein said means for distinguishing also modifies said common-mode information.    
     
     
         21 . The circuit of claim  52  further comprising a means for variably adjusting said modification of said common-mode information.  
     
     
         22 . An audio enhancement system comprising: 
 a pair of circuits that receive at least a pair of audio signals, said pair of circuits are configured to distinguish common-mode information which is common to said audio signals from differential information which is not common to said audio signals; and    a first cross-over network in communication with said pair of circuits, said first cross-over network configured to emphasize a first set of frequencies in said differential information relative to a second set of frequencies in said differential information.    
     
     
         23 . A method of enhancing audio information comprising the steps of: 
 receiving at least two audio signals with a pair of circuits which distinguish common-mode information which is common to said audio signals from differential information which is not common to said audio signals; and    spectrally shaping said differential information with multiple cross-over networks which are in communication with said pair of circuits.