This AtlasIED extra-depth enclosure with acoustic fiberglass lining extends quality and enhances performance of 8" dia. commercial and professional speakers. The increased volume of this enclosure extends the low frequency response by improving acoustic loading. Backbox inner surfaces are undercoated to prevent metallic resonance in the higher end of the frequency spectrum and lined with 1 1/2" (38 mm) thick high density fiberglass (1 1/2 lbs. per cu. ft.). This unit is designed for recessed mounting and includes adjustable mounting bracket for installation flexibility in a variety of ceiling types and depths. Constructed of heavy-gauge CRS and include four conveniently located combination conduit knock-outs to facilitate installation. Finished in rust-preventive, textured black coating.