Patent ID: 6038323
Filing Date: 2000-03-14
Classification: H04R

Abstract:
A stereo signal processing system, in a vehicular sound system having first and second stereo channel signal paths receiving stereo source signals, for enhancing stereo image focus and sound stage in a symmetrical manner for listeners located at right and left locations in a vehicle, comprising:a summed filter network, inserted in at least one of the stereo channel signal paths, configured and arranged to introduce a rapid rate-of-change of phase shift, equal to at least 90 degrees per octave approaching a maximum of approximately 180 degrees, between the stereo channels at approximately 300 Hz said summed filter network comprising:a low-pass filter of order n and having a cut-off frequency approximating 300 Hz, inserted in a first branch of the first stereo channel signal path;a high-pass filter of order n' and having a cut-off frequency approximating 300 Hz, inserted in a second branch of the first stereo channel signal path; anda summing device, receiving input from said low-pass filter in the first branch and from said high-pass filter in the second branch, configured and arranged to provide as output a summed filtered signal;said stereo signal processing system further comprising a phase shifter of an order n"" inserted in the second stereo channel signal path so as to constitute, along with said summed filter network, a phase-conditioning processor block providing a pair of phase-conditioned stereo signals as a main output signal for purposes of image-enhancement of stereo sound within the vehicle.