An apparatus for decoding a signal comprising: a transient separator (310; 410; 510; 610; 710; 910) for separating an apparatus input signal into a first signal component and into a second signal component such that the first signal component comprises transient signal portions of the input signal and such that the second signal component comprises non-transient signal portions of the input signal; a transient decorrelator (320; 420; 520; 620; 720; 920) for decorrelating the first signal component according to a first decorrelation method to obtain a first decorrelated signal component; a further second decorrelator (330; 430; 530; 630; 730; 930) for decorrelating the second signal component according to a second decorrelation method to obtain a second decorrelated signal component, wherein the second decorrelation method is different from the first decorrelation method; a combining unit (340; 440; 540; 640; 740; 940) for combining the first decorrelated signal component and the second decorrelated signal component to obtain a decorrelated combination signal; and a mixer (450; 552; 752; 952), being adapted to receive mixer input signals and being adapted to generate output signals based on the mixer input signals and a mixing rule; wherein the combining unit (340; 440; 540; 640; 740; 940) and the mixer (450; 552; 752; 952) are arranged so that the decorrelated combination signal is fed into the mixer (450; 552; 752; 952) as a first mixer input signal and that the apparatus input signal or a signal derived from the apparatus input signal is fed into the mixer (450; 552; 752; 952) as a second mixer input signal. a transient separator (310; 410; 510; 610; 710; 910) for separating an apparatus input signal into a first signal component and into a second signal component such that the first signal component comprises transient signal portions of the input signal and such that the second signal component comprises non-transient signal portions of the input signal; a transient decorrelator (320; 420; 520; 620; 720; 920) for decorrelating the first signal component according to a first decorrelation method to obtain a first decorrelated signal component; a further second decorrelator (330; 430; 530; 630; 730; 930) for decorrelating the second signal component according to a second decorrelation method to obtain a second decorrelated signal component, wherein the second decorrelation method is different from the first decorrelation method; a combining unit (340; 440; 540; 640; 740; 940) for combining the first decorrelated signal component and the second decorrelated signal component to obtain a decorrelated combination signal; and a mixer (450; 552; 752; 952), being adapted to receive mixer input signals and being adapted to generate output signals based on the mixer input signals and a mixing rule; wherein the combining unit (340; 440; 540; 640; 740; 940) and the mixer (450; 552; 752; 952) are arranged so that the decorrelated combination signal is fed into the mixer (450; 552; 752; 952) as a first mixer input signal and that the apparatus input signal or a signal derived from the apparatus input signal is fed into the mixer (450; 552; 752; 952) as a second mixer input signal.