Higher-Order Loudspeakers and Active Compensation for Improved 2D Sound Field Reproduction in Rooms

This research paper considers the generation of actively compensated 2D sound fields in a semireverberant room using an array of five third-order loudspeakers that exploit room reflections to improve reproduction quality. The loudspeakers and the calibration microphone were cylindrical designs since that geometry is less expensive than spherical designs and better suited to 2D reproduction. The results show that active compensation using higher order loudspeakers can produce sound fields with attenuated early reflections and reduced early reverberation over a radius of 90 mm, large enough for a single listener. Furthermore, third-order sources produced greater suppression of early reflections than zeroth-order sources; the frequency response could be equalized over a wider range.