Dynamic decorrelator for audio signals

A dynamic decorrelator for decorrelating a first input signal and a second input signal comprising:

• a first allpass filter configured to phase shift the first input signal by a first phase shift;
• a second allpass filter configured to phase shift the second input signal by a second phase shift;
• and
• a mono detection circuit configured to detect the similarity of the first input signal and the second input signal and to adjust the magnitude of the first phase shift and the second phase shift according to the similarity of the first input signal and the second input signal, wherein the range of possible phase shift values comprises at least two non-zero values;
• wherein the first input signal is a left rear surround signal imaged by a processor to render a virtual left rear surround signal and wherein the second input signal is a right rear surround signal imaged by the processor to render a virtual right rear surround signal.