A device for encoding an input audio signal into a channel-independent representation comprising a multichannel output audio signal for reproduction over a multiple loudspeaker system, the device comprising: means for receiving the input audio signal comprising a plurality N of input audio channels a i, where i is an index referring to the i th input audio channel a i; means for defining a space D covering a target audience and for partitioning the space D into a plurality K of portions s k independent from the plurality N of input audio channels a i, where k is an index referring to the portion s k of a partition set S formed by the collection of the plurality K of portions s k; means for generating at least one spatial presence factor m i, k for each combination of an input audio channel a i and portion s k, wherein each spatial presence factor m i, k is a real number between 0 and 1 quantifying a degree of presence of each input audio channel a i into each portion s k of space D; means for mapping the input audio signal to the output audio signal, for reproduction within the portions s k, based on the value assigned to each spatial presence factor m i, k; means for generating metadata comprising the spatial presence factors m i, k and information describing the space D and the partitioning of the space D into the plurality of portions s k; and means for associating the metadata with the output audio signal; wherein the space D is defined by selecting a space D with an arbitrary shape, a spherical shape, a rectangular shape, or any other surface, wherein a relation between the input audio signal and the output audio signal is represented by the expression output i, k = a i · m i,k, wherein the channel-independent representation is generated as the set of all products a i · m i, k for all i and all k, one such product for every combination of the input audio channels a i in the input audio signal and the portions s k in the partition set S, or wherein a relation between the input audio signal and the output audio signal is represented by the expression output k = ∑ i = 1 N a i ⋅ m i, k, wherein the channel-independent representation is generated as the set of sums of a i · m i, k over all the input audio channels a i in the input audio signal, each sum corresponding to mixing all input audio channels a i in a given portion s k of the partition set S, weighted according to their spatial presence factor m i, k. means for receiving the input audio signal comprising a plurality N of input audio channels a i, where i is an index referring to the i th input audio channel a i; means for defining a space D covering a target audience and for partitioning the space D into a plurality K of portions s k independent from the plurality N of input audio channels a i, where k is an index referring to the portion s k of a partition set S formed by the collection of the plurality K of portions s k; means for generating at least one spatial presence factor m i, k for each combination of an input audio channel a i and portion s k, wherein each spatial presence factor m i, k is a real number between 0 and 1 quantifying a degree of presence of each input audio channel a i into each portion s k of space D; means for mapping the input audio signal to the output audio signal, for reproduction within the portions s k, based on the value assigned to each spatial presence factor m i, k; means for generating metadata comprising the spatial presence factors m i, k and information describing the space D and the partitioning of the space D into the plurality of portions s k; and means for associating the metadata with the output audio signal; wherein the space D is defined by selecting a space D with an arbitrary shape, a spherical shape, a rectangular shape, or any other surface, wherein a relation between the input audio signal and the output audio signal is represented by the expression output i, k = a i · m i,k, wherein the channel-independent representation is generated as the set of all products a i · m i, k for all i and all k, one such product for every combination of the input audio channels a i in the input audio signal and the portions s k in the partition set S, or wherein a relation between the input audio signal and the output audio signal is represented by the expression output k = ∑ i = 1 N a i ⋅ m i, k, wherein the channel-independent representation is generated as the set of sums of a i · m i, k over all the input audio channels a i in the input audio signal, each sum corresponding to mixing all input audio channels a i in a given portion s k of the partition set S, weighted according to their spatial presence factor m i, k. wherein the space D is defined by selecting a space D with an arbitrary shape, a spherical shape, a rectangular shape, or any other surface, wherein a relation between the input audio signal and the output audio signal is represented by the expression output i, k = a i · m i,k, wherein the channel-independent representation is generated as the set of all products a i · m i, k for all i and all k, one such product for every combination of the input audio channels a i in the input audio signal and the portions s k in the partition set S, or wherein a relation between the input audio signal and the output audio signal is represented by the expression output k = ∑ i = 1 N a i ⋅ m i, k, wherein the channel-independent representation is generated as the set of sums of a i · m i, k over all the input audio channels a i in the input audio signal, each sum corresponding to mixing all input audio channels a i in a given portion s k of the partition set S, weighted according to their spatial presence factor m i, k.