Large-Scale Loudspeaker System Calibration, from Simulation-Based Design to Onsite Tuning

Presenters:
Etienne Corteel, L-Acoustics - Marcoussis, France
François Montignies, L-Acoustics - Marcoussis, France
Scott Sugden, L-Acoustics - Oxnard, CA, USA

The objective of a calibration is to ensure that the onsite performances of a loudspeaker system meet specific project requirements. It implies the optimization of the solution that was defined at the design stage, accounting for the environment in which the system was implemented. Onsite tuning is at the core of the process. It adopts a check and adjust approach, using measurements and electronic settings to reach a defined level of expectation. The calibration should not be a solution to correct major design issues, whether they come from the manufacturer or from the user. Nowadays, high-end manufacturers provide the user with loudspeaker processing presets that optimize direct-sound and multi-way crossovers. That removes a lot of the onsite optimization process that was performed by the users in the past. However, a meticulous definition of the sound system solution is still critical, especially in the physical deployment of a system. On this aspect, the use of advanced modeling and simulation software minimizes the risk for design errors. Simulation-based design also allows to anticipate most of the electronic settings to further reduce the onsite tuning time. One additional and major benefit is that a 3D simulation gives an overview of the results over the whole audience area, whereas onsite tuning needs to rely on a limited number of measurements locations, leading to high risk of wrong electronic adjustment choices. This tutorial presents a complete optimization process that starts at the design stage, planning the physical deployment parameters, the zoning groups within line source arrays, the optimal main-sub alignment location and the time-alignment of fill systems. Onsite tuning can then use measurements and critical listening to validate the planned solution and to address remaining simulation uncertainties.