An analytical approach to sound field reproduction with a movable sweet spot using circular distributions of loudspeakers

Sound field reproduction methods like higher order Ambisonics which are based on orthogonal expansions always introduce a limitation of the spatial bandwidth of the secondary source driving function. This spatial truncation creates a sweet spot in the center of the secondary source distribution. This spot, or rather area, is ldquosweetrdquo both in terms of spatial aliasing artifacts as well as in terms of accuracy of the desired component of the reproduced wave field. The higher the temporal frequency of the reproduced wave field the smaller is the sweet spot. In this paper we show that the location sweet spot can be moved freely inside the secondary source distribution. The accuracy of the actual reproduced wave field is then significantly higher in the sweet spot than in the same region in the conventional approach.