Digital processor for a loudspeaker reproduction system with exactly three or four front loudspeakers, the digital processor comprising: an ambient portion extractor configured to extract an ambient portion from a stereo signal; a spatial effect processing stage, configured to generate a spatial effect signal based on the ambient portion of the stereo signal; and a multi-channel processing stage configured to generate a processed version of the stereo signal, wherein the processed version of the stereo signal comprises exactly one or two more channels than the stereo signal, wherein the multi-channel processing stage is configured to generate an individual stereo sound stage signal as the processed version of the stereo signal from the stereo signal for generating with the loudspeaker reproduction system at least two respective individual stereo sound stages for at least two different listening positions, wherein the spatial effect processing stage comprises a decorrelator configured to decorrelate the ambient portion of the of stereo signal to obtain a decorrelated signal, the decorrelated signal comprising two more channels than the stereo signal, wherein the spatial effect processing stage further comprises a binauralization stage configured to apply the same spatial binaural filters to the channels of the decorrelated signal corresponding to the at least two different listening positions, wherein the spatial effect processing stage further comprises a listener envelopment modifier connected either in parallel or in series with the binauralization stage, the listener envelopment modifier being configured to apply different binaural filters either to channels of the decorrelated signal corresponding to the at least two different listening positions, when the binauralization stage and the listener envelopment modifier are connected in parallel, or to the output channels of the binauralization stage corresponding to the at least two different listening positions, when the binauralization stage and the listener envelopment modifier are connected in series, wherein the digital processor further comprises an adder configured to channel wise add the processed version of the stereo signal with the spatial effect signal to obtain a signal for the exactly three or four front loudspeakers. an ambient portion extractor configured to extract an ambient portion from a stereo signal; a spatial effect processing stage, configured to generate a spatial effect signal based on the ambient portion of the stereo signal; and a multi-channel processing stage configured to generate a processed version of the stereo signal, wherein the processed version of the stereo signal comprises exactly one or two more channels than the stereo signal, wherein the multi-channel processing stage is configured to generate an individual stereo sound stage signal as the processed version of the stereo signal from the stereo signal for generating with the loudspeaker reproduction system at least two respective individual stereo sound stages for at least two different listening positions, wherein the spatial effect processing stage comprises a decorrelator configured to decorrelate the ambient portion of the of stereo signal to obtain a decorrelated signal, the decorrelated signal comprising two more channels than the stereo signal, wherein the spatial effect processing stage further comprises a binauralization stage configured to apply the same spatial binaural filters to the channels of the decorrelated signal corresponding to the at least two different listening positions, wherein the spatial effect processing stage further comprises a listener envelopment modifier connected either in parallel or in series with the binauralization stage, the listener envelopment modifier being configured to apply different binaural filters either to channels of the decorrelated signal corresponding to the at least two different listening positions, when the binauralization stage and the listener envelopment modifier are connected in parallel, or to the output channels of the binauralization stage corresponding to the at least two different listening positions, when the binauralization stage and the listener envelopment modifier are connected in series, to channels of the decorrelated signal corresponding to the at least two different listening positions, when the binauralization stage and the listener envelopment modifier are connected in parallel, or to the output channels of the binauralization stage corresponding to the at least two different listening positions, when the binauralization stage and the listener envelopment modifier are connected in series, wherein the digital processor further comprises an adder configured to channel wise add the processed version of the stereo signal with the spatial effect signal to obtain a signal for the exactly three or four front loudspeakers.