Enhancing subjective spaciousness for stereo reproduction in car-size acoustical enclosures based on audio signal decorrelation

Audio signal decorrelation has been used for enhancing the spaciousness of auditory source width (ASW) in a stereo reproduction. However, the acoustic environment in car-size acoustical enclosures is quite different from that in a home theater or listening room. Due to the small cabin size and the substantial presence of absorptive surfaces, the reproduced sound field in car-size acoustical enclosures is characterized by the interior mode region up to some hundreds or one thousand hertz and fast decay of pressure at higher frequencies which could affect the perceived performance of audio signal decorrelation. Therefore, the present work evaluates the effect of reflections in an acoustical enclosure model with car-size on the ASW enhanced by decorrelated audio signals, which reproduced by a standard stereo system. The decorrelation algorithm is handled by all-pass filters sets based on a pair of reciprocal maximal length sequence (MLS). Last, a subjective assessment experiment of ASW validates that appropriate decorrelation method can improve perceived spaciousness for sound reproduction in car-size acoustical enclosures.