Development of Ad Hoc Loudspeaker Arrays Using Smart Devices

Traditional loudspeaker arrays are effective in creating immersive auditory experiences but face real-time challenges related to adaptability, particularly regarding the number and location of speakers. Although smart devices have the potential to address these limitations, there is a lack of research exploring their use, especially in indoor settings. Our study addresses this gap by proposing an ad hoc loudspeaker array system that leverages smart devices for real-time audio spatialization. The system employs a modified "room within a room" spatialization method, dynamically defining the listening area using the convex hull formed by the loudspeakers. Ultra-wideband (UWB) technology is utilized for precise indoor location, allowing speakers to move in the horizontal plane while maintaining accurate audio spatialization. Developed as an iOS application, the system was inherently limited in the number of interconnecting devices, and was subjectively evaluated using both moving and stationary stimuli and loudspeakers. Results consistently indicated positive ratings for moving stimuli, regardless of speaker motion, while stationary stimuli received lower ratings. This suggests potential areas for improvement, such as increasing the number of devices allowed to connect. These findings demonstrate the feasibility of using commercially available smart devices to create flexible loudspeaker arrays, with implications for the development of more adaptable and user-friendly spatial audio systems.