Spatial sound reproduction systems based on loudspeakers are known from the traditional stereo setup with 2 loudspeakers to surround sound systems with 4 - 6 loudspeaker or more. These systems typically have to be placed in a closed space for example a rectangular room. Every rectangular room has a strong low frequency influence at the reproduced sound due to its parallel walls, and is often problematic to control by acoustic means. The combination of more than one sound source placed in a room makes it even more difficult to control the sound field as we move to the low frequency area. The aim of this Ph.D. study project is to carry out an extensive investigation within the reproduction of spatial sound with multiple loudspeakers in a listening room. The aim is to improve the sound in a restricted listening area by controlling the signal to the individual loudspeakers by mean of adaptive equalization in combination with other methods using digital signal processing.