2 Pairs of Definitive Technology BP-8060 with Built-In Powered Subwoofers + 2 Pairs of A60 Elevation Module that supports Dolby Atmos decoding and playback + Definitive Technology CS-8040HD Center Channel Definitive Technology BP-8060ST: Bipolar technology for huge room-filling sound for every listener in the room Definitive Technology BP-8060ST: Built in 300 watt powered subwoofer delivers massive bass, eliminating the need for a separate subwoofer Definitive Technology's A60 Elevation Module (Pair): A60 Elevation Module supports Dolby Atmos decoding and playback. Definitive Technology CS-8040HD: 5" x 10" low bass radiator for extended bass response; One inch pure Alluminum dome tweeter