Digital Signal Processing and System Theory

Talk Mirco Scheil

Development of an Audio Upmix Scheme for Spatial Playback of Stereo Sources

Date: 07.11.2013, 13:30 h - 14:00 h
Room: Aquarium

Mirco Scheil
CAU, Kiel, Germany,


While 5.1 surround multichannel audio systems are being adopted widely by consumers, most audio content is still available in the two-channel stereo format. For audio systems enhancing the sound experience beyond stereo, it is thus crucial that stereo audio content can be played back, desirably with an improved experience compared to the legacy systems.

The benefit by using more front loudspeakers will be an increased width of the virtual sound stage and an extended sweet-spot region. Lateral independent sound components can be played back seperately over loudspeakers on the sides of a listener to increase listener envelopment.


 In this thesis a real-time upmix-algorithm will be developed within the Kiel Real-Time Audio Tool kit (KiRAT) using the programming language C. The aim will be to play back stereo signals over more than two loudspeakers for an improved listener experience. After using analysis filterbanks a spatial decomposition of the two-channel audio signal will be performed with correlation- and coherence-based analyses. Given the spatial decomposition of the stereo signal, the single loudspeaker signals can be generated.