Stereo sound field enlarging circuit

Claim 1

In a stereo sound field enlarging circuit in which signals A and B applied to two input terminals are processed to provide signals A' and B' at two respective output terminals, the improvement comprising: means, including a first and a second low pass filter, for producing said signals A' and B' from said signals A and B in accordance with the following equations, A'=|A|.sub.LPF +K(A-B) B'=|B|.sub.LPF +K(B-A), where |A| LPF is the signal A passed through said first low-pass filter, |B| LPF is the signal B passed through said second low-pass filter, and K is a constant, said first and second low pass filters being respectively connected to said first and second input terminals and receiving said signals A and B; difference circuit means connected between said two input terminals for producing a difference signal (A-B); multiplier means for multiplying said difference signal to produce multiplied difference signals K (A-B) and K (B-A), where K is a constant; first adder circuit means for receiving the multiplied signal K (A-B) and the output of the first low pass filter for producing output signal A'; and second adder circuit means for receiving the multiplied difference signal K (B-A) and the output of said second low pass filter to produce said signal B'.