PSB CSIW SUB28 – Dual 8″ In-Wall Subwoofer is a premium in wall sealed cabinet subwoofer with dual 8” high performance drivers capable of delivering detailed low frequency performance. Equipped with heavy duty nylon dog-ears, and a magnetic small perforation grille, the CSIW SUB28 can be used in both new construction or retrofit applications. Versatile, and easy to deploy, the CSIW SUB28 is a cornerstone of hidden audio system design.