Sound quality described by being hard to localize and fully filling a listening area; spread out. A diffuse sound field is one that encompasses the listener filling the listening space without being very directional (having low directivity). diffuse sound is often striven for in surround channels to create an enveloping effect and create a believable sonic environment without drawing attention from the directive sound of the front channels (left, center and right). This is accomplished mainly by using dipolar and bipolar speakers for the surround channels and placing them high on the wall to the sides of the listener. Their sound emanates to the front and back along the wall instead of directly to the listener. The sound reaching the listener thus comes in large part from reflections with the walls and other surfaces. This process makes the sound seem to come from all around the listener instead of emanating from the speakers – a diffuse sound. nother technique used to create diffuse sound field with matrixed surround sound formats is decorrelation. Decorrelation is a part of the THX program for home theater use when using matrix surround technology (it is not used with the discrete, stereo surround channels found in Dolby Digital and DTS 5.1 digital surround formats). Decorrelation breaks up the mono (one channel) sound of matrix systems and sends the signal in two pieces out of phase with one another to a pair of surround speakers. The technique further creates a diffuse listening environment and, when combined with dipolar speakers as per THX specifications, can make the surround speakers themselves almost completely impossible to localize resulting in a very diffuse, enveloping sound field.