A stereo-base widening system producing a good effect, achievable with a simple analog circuit as well as with a digital one, is presented. The system is derived from a combination of the traditional approach using head-related transfer functions (HRTFs), and by using a simple model where ideal loudspeakers and an acoustically transparent subject's head are assumed. Both the HRTF approach and the simple model are discussed, and some special cases for the latter are considered. Merging these models with some experimentally determined adaptations led to a practical widening system. The system produces a pleasant and natural sound, particularly for voices and normal mixed stereo recordings. The widening circuit is tuned in such a way that for common stereo recordings it gives the same tonal balance as conventional stereo reproduction. For sound effects as in action movies, the system produces extreme effects, which was a deliberate design goal of the system.
|Number of pages
|Journal of the Audio Engineering Society
|Published - 1 Mar 2000