AES Show 2024 NY

A sound reinforcement system typically combines a full-range system with a subwoofer system to deliver a consistent frequency bandwidth. The two systems must be time-aligned, which is usually done without an audience. This paper investigates the impact of the audience on the time alignment of loudspeaker systems at low frequencies. The study demonstrates, through on-site measurements and simulations, that the audience significantly affects sound propagation. The research highlights the greater phase shift observed with ground-stacked subwoofers compared to flown systems due to the audience’s presence, requiring adjustments of the system time alignment with the audience when flown and ground-stacked sources are used together. Moreover, in this case, the results demonstrate the lower quality of the summation with the audience even with the alignment adjustment. Lastly, recommendations for system design and calibration are proposed.