Incoherent Idempotent Ambisonics Rendering

We describe a family of ambisonics rendering methods that is based on optimizing the soundfield component that lies in the null space of the operator that maps the loudspeaker signals onto the given ambisonics representation. In contrast to traditional rendering approaches, the new method avoids the coherent addition of loudspeaker contributions to the sound field. As a result, it provides a space-invariant timbre and good spatial directionality outside the spatial region where the ambisonics soundfield description is accurate. The new method is idempotent at all frequencies and has relatively low computational complexity. Our experimental results confirm the effectiveness of the method.