Spatio-temporal structure of sound fields synthesized by HOA & WFS

The following two videos show the synthesis of a broadband plane wave using near-field compensated higher-order Ambisonics (NFC-HOA) and Wave Field Synthesis (WFS). A circular system with a diameter of 3 meters consisting of 56 loudspeakers was simulated numerically. The situation constitutes a 2.5-dimensional synthesis scenario.  The desired plane wave travels from the top to the bottom of the circular system. The temporal bandwidth is 44.1 kHz.

The first video shows the synthesis using 2.5D NFC-HOA

It can be observed that the desired plane wave is synthesized accurately only in small circular region in the center of the system. Outside of this region artifacts due to spatial sampling and spatial bandlimitation can be observed.

The second video shows the synthesis using 2.5D WFS

It can be observed that the first wave front of the desired plane wave is synthesized. However, behind this first wavefront a series of additional wave fronts can be seen which are due to the saptial sampling of the secondary sources.

Note, that the perceptual implications of these artifacts are not clear at the current state of research.

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