The stereo widening CAO is mainly used to extend stereo width and proper stage image. It helps to extend stereo image beyond the front speaker locations towards side and Rear. It also helps to place phantom centre between front speakers.
Stereo Widening 2.0 is a technology that utilizes amplitude panning to realize a stable and tunable phantom center image as well as tunable stereo side content for the perceived width. It has small MIPS/MEM footprint, and is suitable for larger speaker systems with minimum 4 channels.
In implementation, amplitude panning is used to shift side (de-correlated) content to rear speakers while mono part is panned to (phantom) center. The widening effect is applied to outer signal parts, possibly to emphasize reverberation, side-panned content, etc. Position of phantom center can be modified by the user, and its stability can be controlled by level setting of the mono part.
