An audio decoder comprising: effect means for generating modified down-mix audio signals from received down-mix audio signals, said received down-mix audio signals comprising a down-mix of a plurality of audio objects, the effect means being arranged to: generate estimated audio signals from the received down-mix audio signals based on received parametric data comprising a plurality of object parameters for each of the plurality of audio objects, the estimated audio signals corresponding to one or more audio objects comprised in said received down-mix audio signals, and obtain said modified down-mix audio signals by applying effects to the estimated audio signals; decoding means being arranged for decoding the audio objects from the down-mix audio signals or the modified down-mix audio signals based on the parametric data; rendering means being arranged for generating at least one output audio signal from the decoded audio objects; wherein the audio decoder is, based on a type of the applied effect, arranged to: for the type of applied effect being an insert effect, decode said modified down-mix audio signals by the decoding means; or for the type of applied effect being a send effect, rendering said modified down-mix audio signals by the rendering means or combining said modified down-mix audio signals with the output of rendering means; and the generation of the estimated audio signals comprises time/frequency dependent scaling of the down-mix audio signals based on power parameters corresponding to audio objects, said power parameters being comprised in the parametric data. generate estimated audio signals from the received down-mix audio signals based on received parametric data comprising a plurality of object parameters for each of the plurality of audio objects, the estimated audio signals corresponding to one or more audio objects comprised in said received down-mix audio signals, and obtain said modified down-mix audio signals by applying effects to the estimated audio signals; decoding means being arranged for decoding the audio objects from the down-mix audio signals or the modified down-mix audio signals based on the parametric data; rendering means being arranged for generating at least one output audio signal from the decoded audio objects; wherein the audio decoder is, based on a type of the applied effect, arranged to: for the type of applied effect being an insert effect, decode said modified down-mix audio signals by the decoding means; or for the type of applied effect being a send effect, rendering said modified down-mix audio signals by the rendering means or combining said modified down-mix audio signals with the output of rendering means; and for the type of applied effect being an insert effect, decode said modified down-mix audio signals by the decoding means; or for the type of applied effect being a send effect, rendering said modified down-mix audio signals by the rendering means or combining said modified down-mix audio signals with the output of rendering means; and the generation of the estimated audio signals comprises time/frequency dependent scaling of the down-mix audio signals based on power parameters corresponding to audio objects, said power parameters being comprised in the parametric data.