Commonly used types of loudspeaker systems have directional patterns that bear no relationship to those of the sound sources which they purport to simulate. The purpose of this project is to derive some parameters linked to the radiation and relevant to our perception. To address this problem, a series of three separate experiments have been conducted: (1) collect data on sound power spectra and directional characteristics of musical instruments to be simulated. (2) build of a multiple drivers reproduction system with signal processing control. (3) investigate the physical and psychophysical properties of this sound source when the directional programming is varied. The influence of the coupling of the sound source and the room on the perception of the simulated sound sources is also examined.