Timbral Coloration in High Resolution Sound Field Reproduction Due to Spatial Bandwidth Limitation

Sound field reproduction methods based on orthogonal expansions like e.g. higher order Ambisonics always introduce a limitation of the spatial bandwidth of the loudspeaker driving signals. As a consequence, the desired component of the reproduced wave field is similarly bandlimited. This leads to a pronounced sweet spot around the center of the loudspeaker distribution. This area is sweet both in terms of spatial aliasing artifacts as well as in terms of accuracy of the desired component of the reproduced wave field. The sweet spot gets significantly smaller with increasing temporal frequency. This means that outside the center of the loudspeaker distribution, the point of most accurate reproduction, frequency dependent artifacts arise. In this paper, we objectively investigate the resulting artifacts for circular loudspeaker arrangements with a focus on potential consequences on human perception.