Deluxe 8" Surface Mount Square Enclosure 8" Deep Atlas Sound model SM191-78-8 extra-depth surface mount enclosure with acoustic fiberglass lining extends quality and enhances performance of 8" dia. commercial and professional loudspeakers.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 11/2" (38 mm) thick high density fiberglass (11/2 lbs. per cu. ft.).Unit is constructed of heavy-gauge CRS and include four conveniently located combination conduit knock-outs to facilitate installation. Surface model is finished in textured white.