Speaker
Description
Sound spatialization techniques have proved effective for voice reinforcement in theaters, as they enable the synthesis of virtual sources that are co-located with the real sources on stage, thereby preserving the spatial coherence of the scene. However, in the case of wide front-fill arrays and off-center source positions, this approach generally concentrates the energy toward the side of the source, which compromises the listening comfort for a part of the audience seated on the opposite side, particularly those in the vicinity of the front-fill array. This is the case, for instance, with Wave Field Synthesis (WFS), whose driving functions yield low driving gains for loudspeakers on the opposite side of an off-center source. To address this limitation, we present a Large-Stage Compensation (LSC) of loudspeaker driving gains, tuned using computational perceptual models. It empirically increases the gains of loudspeakers located on the opposite side while keeping delay values unchanged to maintain the desired wavefront curvature. Acoustic and perceptual metrics (such as energetic coverage, speech transmission index, localization accuracy, and coloration) are simulated to evaluate and optimize the method, finding a balance between improved intelligibility and limited degradation in spatial and timbral quality. The LSC is modulated according to the source’s position on stage, and it is gradually applied only for critical off-center positions. The proposed method is evaluated using a simulation of a 30-meter-wide front-fill system at the 'Palais des Papes' in Avignon. Results show that the LSC improves energetic coverage and speech intelligibility, with moderate, quantifiable increases in coloration and localization errors.