Disappearing In-Walls Advanced TechnologyThe Disappearing In-Wall models feature Definitive s most advanced technologies such as BDSS drivers and pivoting Pure Aluminum dome tweeters for spectacular audio performance far beyond traditional flush-mount speakers. Definitive s exclusive Balanced Dual Surround System (BDSS) driver technology permits these new flush mounts to deliver more bass output and dynamic range than larger drivers. For example, the 4-1/2" driver-based model has the bass and dynamics of a 5-1/4" traditional speaker, while the 5-1/4" performs like a traditional 6-1/2", and so on. With a pivoting 1" Pure Aluminum dome tweeter featuring a specially shaped housing that avoids the diffraction distortions of traditional post-mounted tweeters, and a sophisticated adjustable crossover network, the Disappearing In-Wall models deliver the kind of lifelike sonic performance and broad even dispersion that have made Definitive Technology the most highly reviewed speaker brand in the USA. Fire-rated pre-construction enclosures will be available as options, allowing integrators, architects and designers to specify Disappearing In-Wall Speakers in multi-family and commercial applications.