Renderer controlled spatial upmix

A method for decoding a compressed input audio signal, the method comprising:

• providing at least one core decoder comprising one or more processors for generating a processor output signal based on a processor input signal, wherein a number of output channels of the processor output signal is higher than a number of input channels of the processor input signal, wherein each of the one or more processors comprises a decorrelator and a mixer, wherein a core decoder output signal comprising a plurality of channels comprises the processor output signal, and wherein the core decoder output signal is suitable for a reference loudspeaker setup;
• providing at least one format converter device configured to convert the core decoder output signal into an output audio signal, which is suitable for a target loudspeaker setup;
• and
• providing a control device configured to control at least one or more processors in such way that the decorrelator of the processor is controlled independently from the mixer of the processor, wherein the control device is configured to control at least one of the decorrelators of the one or more processors in such way that, depending on the target loudspeaker setup, the mixer of the processor is operational when the decorrelator of the processor is switched off.