- Sound system renovation in the Lille Flandres Station -  
Considering the complexity of a sound system in such a space (big reverberant hall with many sources of noise), we used CATT-Acoustic software to predict the sound quality and especially the intelligibility of messages in the station. Initially, room impulse response and spatial decay measurements were performed in order to configure the calculation parameters of the model designed. From this geometric model, many kind of sound systems were studied :

• standard multidiffusion systems
• innovative Digital Directivity Controlled (DDC) loudspeaker arrays

The originality of the DDC array led us to validate them by a test in situ. During this test, SPL and RASTI were measured in the diffusion area with a sharp step. Given that the simulation of such a loudspeaker didn't correlate satisfactorily with the initial measurements, CATT’s developer launched into the improvement of the directivity model by means of the DLL interface.