Abstract: Techniques of performing ambisonic coding involve coupling channels of a high-order ambisonics (HOA) signal using a projection matrix based on positions of a set of loudspeakers on a unit sphere to form a projected HOA signal. Each pair of components of the projected HOA signal may then be encoded into a stereo format. In some arrangements, the projection matrix may be based on a decoding or demixing matrix that is in turn based on spherical harmonics evaluated at specified loudspeaker positions. In this way, the encoding efficiency (e.g., bitrate for a given sound quality) is improved over the conventional approaches to performing ambisonic coding.