Available For The First Time In Nearly 50 Years Transferred From The Original Half-Inch Four-Channel Masters Blu-ray With 192/24 Resolution Quadraphonic And Hi-Res Stereo Mixes Quadraphonic sound, or 4.0 surround sound, utilizes four audio channels connected to four speakers positioned at the corners of a listening space. The multi-tracked audio is mixed dimensional, immersing the listener in an expansive soundscape.