A method comprising: receiving audio data comprising a first set of frequency coefficients and a second set of frequency coefficients; estimating, based on at least part of the first set of frequency coefficients, spatial parameters for at least part of the second set of frequency coefficients; and applying the estimated spatial parameters to the second set of frequency coefficients to generate a modified second set of frequency coefficients, wherein the first set of frequency coefficients corresponds to a first frequency range and the second set of frequency coefficients corresponds to a second frequency range; wherein the audio data comprises data corresponding to individual channels and a coupled channel, and wherein the first frequency range corresponds to an individual channel frequency range and the second frequency range corresponds to a coupled channel frequency range; wherein the audio data comprises frequency coefficients in the first frequency range for two or more channels; and wherein the estimating process involves: creating a composite coupling channel based on audio data of the individual channels in the first frequency range, which involves calculating combined frequency coefficients of the composite coupling channel based on frequency coefficients of the two or more channels in the first frequency range; and computing, for at least a first channel, cross-correlation coefficients between frequency coefficients of the first channel and the combined frequency coefficients. receiving audio data comprising a first set of frequency coefficients and a second set of frequency coefficients; estimating, based on at least part of the first set of frequency coefficients, spatial parameters for at least part of the second set of frequency coefficients; and applying the estimated spatial parameters to the second set of frequency coefficients to generate a modified second set of frequency coefficients, wherein the first set of frequency coefficients corresponds to a first frequency range and the second set of frequency coefficients corresponds to a second frequency range; wherein the audio data comprises data corresponding to individual channels and a coupled channel, and wherein the first frequency range corresponds to an individual channel frequency range and the second frequency range corresponds to a coupled channel frequency range; wherein the audio data comprises frequency coefficients in the first frequency range for two or more channels; and wherein the estimating process involves: creating a composite coupling channel based on audio data of the individual channels in the first frequency range, which involves calculating combined frequency coefficients of the composite coupling channel based on frequency coefficients of the two or more channels in the first frequency range; and computing, for at least a first channel, cross-correlation coefficients between frequency coefficients of the first channel and the combined frequency coefficients. creating a composite coupling channel based on audio data of the individual channels in the first frequency range, which involves calculating combined frequency coefficients of the composite coupling channel based on frequency coefficients of the two or more channels in the first frequency range; and computing, for at least a first channel, cross-correlation coefficients between frequency coefficients of the first channel and the combined frequency coefficients.