Apparatus and Method for Synthesizing an Output Signal

An apparatus for synthesizing a rendered output signal having a first audio channel and a second audio channel includes a decorrelator stage (356) for generating a decorrelator signal based on a downmix signal, and a combiner (364) for performing a weighted combination of the downmix signal and a decorrelated signal based on parametric audio object information (362), downmix information (354) and target rendering information (360). The combiner solves the problem of optimally combining matrixing with decorrelation for a high quality stereo scene reproduction of a number of individual audio objects using a multichannel downmix.