A decoder for generating an audio output signal comprising one or more audio output channels, wherein the decoder comprises: a receiving interface for receiving an audio input signal comprising a plurality of audio object signals, for receiving loudness information on the audio object signals, and for receiving rendering information indicating whether one or more of the audio object signals shall be amplified or attenuated, and a signal processor for generating the one or more audio output channels of the audio output signal, wherein the receiving interface is configured to receive a downmix signal comprising one or more downmix channels as the audio input signal, wherein the one or more downmix channels comprise the audio object signals, and wherein the number of the one or more downmix channels is smaller than the number of the audio object signals, wherein the receiving interface is configured to receive downmix information indicating how the audio object signals are mixed within the one or more downmix channels, wherein the receiving interface is configured to receive one or more further by-pass audio object signals, wherein the one or more further by-pass audio object signals are not mixed within the downmix signal, wherein the receiving interface is configured to receive the loudness information indicating information on the loudness of the audio object signals which are mixed within the downmix signal and indicating information on the loudness of the one or more further by-pass audio object signals which are not mixed within the downmix signal, wherein the signal processor is configured to determine a loudness compensation value depending on the information on the loudness of the audio object signals which are mixed within the downmix signal, and depending on the information on the loudness of the one or more further by-pass audio object signals which are not mixed within the downmix signal, and wherein the signal processor is configured to generate the one or more audio output channels of the audio output signal from the audio input signal depending on the downmix information, depending on the rendering information and depending on the loudness compensation value. a receiving interface for receiving an audio input signal comprising a plurality of audio object signals, for receiving loudness information on the audio object signals, and for receiving rendering information indicating whether one or more of the audio object signals shall be amplified or attenuated, and a signal processor for generating the one or more audio output channels of the audio output signal, wherein the receiving interface is configured to receive a downmix signal comprising one or more downmix channels as the audio input signal, wherein the one or more downmix channels comprise the audio object signals, and wherein the number of the one or more downmix channels is smaller than the number of the audio object signals, wherein the receiving interface is configured to receive downmix information indicating how the audio object signals are mixed within the one or more downmix channels, wherein the receiving interface is configured to receive one or more further by-pass audio object signals, wherein the one or more further by-pass audio object signals are not mixed within the downmix signal, wherein the receiving interface is configured to receive the loudness information indicating information on the loudness of the audio object signals which are mixed within the downmix signal and indicating information on the loudness of the one or more further by-pass audio object signals which are not mixed within the downmix signal, wherein the signal processor is configured to determine a loudness compensation value depending on the information on the loudness of the audio object signals which are mixed within the downmix signal, and depending on the information on the loudness of the one or more further by-pass audio object signals which are not mixed within the downmix signal, and wherein the signal processor is configured to generate the one or more audio output channels of the audio output signal from the audio input signal depending on the downmix information, depending on the rendering information and depending on the loudness compensation value.