The path towards genuine spatial audio reproduction
Helmut Oellers, Germany
In the recording room of a sound event, the acoustic source is originating complex pattern of reflections. Truly spatial audio reproduction has to restore the wave fronts of the source itself, as well as her reflections, from its correct starting point – irrespective of the listener's position. That is not feasible in the traditional, phantom source based procedures. The starting points migrate dependently the listener’s position. Assigning all spatial information to some channels cannot truly reconstruct the genuine impression of the recording room. We cannot describe the complex structure of the sonic field simply as the signal difference between some single points. By attempting to increase the immersion with the number of channels, we have lost the substance of the sources itself. We are not really immersed into the sonic field. The sound sources are only around us. Ghostlike now, somehow dematerialized, and disappearing, in case we want draw near.
This site describes a different procedure, aiming at the opposite. During playback the purely, dry in mono recorded sound of the source becomes complemented by the correct reflections. A synthesis creates those wave fronts in the same manner, as the recording room creates all auditory spaciousness from the pure signal of the genuine sound source. That's shown in the little animation above. In difference regarding known Wave Field Synthesis procedure, the described “Holophony” approach allows changing listener's position in the recording room during playback yet. The following chapters will specify the way. In advance, we will be describing the complex problems of the traditional audio procedures.