AES Europe 2026

The inherent narrowing of directivity at high frequencies
in compact tweeters limits the spatial uniformity of sound
reproduction in modern audio systems. Conventional passive
solutions, such as waveguides; acoustic lenses,
partially mitigate this issue but typically rely on bulky
geometries; treat the diaphragm as a unitary radiator,
neglecting localized vibration behavior. This study
proposes a Matrix Wavefront Modulator (MWM), a compact
passive device that implements a differentiated
wavefront-shaping strategy based on vibration-aware
radiation control. Sound radiation from the piston-like
diaphragm dome; the breakup-prone surround is processed
independently by combining guided wavefront steering with
targeted scattering compensation. The geometry of the MWM
is optimized to adapt to the radiation characteristics of
the tweeter. Numerical simulations show that the optimized
MWM reshapes the high-frequency wavefront toward a more
spherical distribution; significantly reduces off-axis
attenuation above 10 kHz. Experimental measurements confirm
significant improvements in high-frequency directivity over
wide radiation angles.