Comparison of Wave Field Synthesis and Higher-Order Ambisonics (invited)

Wave field synthesis (WFS) and higher-order Ambisonics (HOA) are two different approaches to high-resolution spatial sound reproduction. Both aim at the physical reconstruction of a desired wave field within a listening area. This talk will present a comparison of both approaches ranging from their physical foundations to the impact of the approximations applied in practical implementations. For this purpose both approaches will be formulated in a common framework. In order to provide insights into the differences on a physical level, the en- and decoding procedure typically applied to HOA is skipped and HOA is essentially formulated as the solution of an integral equation. WFS will be derived in a similar fashion. In a next step, special attention is drawn to the consequences of spatial sampling as performed in practical implementations using discrete loudspeakers. It is shown that both approaches differ significantly here. First results from listening experiments are presented that illustrate the impact of these physical differences on human perception. Finally some practical aspects like e.g. the complexity of both approaches in terms of the underlying digital signal processing are discussed.