Trinnov is room correction, like Audyssey, which equalizes the sound to give you a smoother/flatter response by minimizing the room's unwanted contributions to the overall sound. However, unlike Audyssey, Trinnov uses a multi-capsule mic in order to map your speakers' locations (distance, elevation, azimuth). This allows Trinnov to do things that Audyssey cannot. For example: Audyssey can correct for varying distances by applying approprate delays to each speaker; Trinnov goes one step further by correcting for varying heights and varying angles. PLIIz tops out at 9 channels max.