The present document relates to multichannel audio coding and more precisely to techniques for discrete multichannel audio encoding and decoding. In particular, the present document relates to systems and method for coding soundfields. An audio encoder (200) configured to encode a frame of a soundfield signal (110) comprising a plurality of audio signals is described. The audio encoder (200) comprises a transform determination unit (203, 204) configured to determine an energy-compacting orthogonal transform (V) based on the frame of the soundfield signal (110). Furthermore, the encoder (200) comprises a transform unit (202) configured to apply the energy-compacting orthogonal transform (V) to the frame of the soundfield signal (110), and configured to provide a frame of a rotated soundfield signal (112) comprising a plurality of rotated audio signals (E1, E2, E3). The audio encoder (200) comprises a waveform encoding unit (103) configured to encode a first rotated audio signal (E1) of the plurality of rotated audio signals (E1, E2, E3), and a parametric encoding unit (104) configured to determine a set of spatial parameters (ae2, be2) for determining a second rotated audio signal (E2) of the plurality of rotated audio signals (E1, E2, E3) based on the first rotated audio signal (E1).