6. An apparatus for processing an audio signal for performing binaural rendering for an input audio signal, the apparatus comprising:a binaural rendering unit configured to:
receive an input audio signal,
receive a set of truncated subband filter coefficients for each subband and each channel, wherein the set of truncated subband filter coefficients is truncated frequency dependently from a set of subband filter coefficients of a binaural room impulse response (BRIR) data set, wherein the length of the set of truncated subband filter coefficients is determined based on a filter order of the corresponding subband, and wherein the filter order is determined to be variable in the frequency domain,
obtain vector information indicating a particular BRIR data set corresponding to a relevant channel of the input audio signal, and
filter each subband signal of the multi-channel signal by using the truncated subband filter coefficients corresponding to the relevant channel and a relevant subband based on the vector information.