D-SP1A Loudspeaker The loudspeaker shall be an RDL D-SP1A (white), DB-SP1A (black), DS-SP1A (stainless steel) or DG-SP1A (gray). The unit shall provide an audio input on a rear-panel detachable terminal block. The nominal speaker impedance shall be 8 O. The driver shall be no less than 1 inch in diameter. The cone shall be constructed of anodized aluminum with a foam suspension. The unit shall produce a nominally hemispherical dispersion when mounted in a wall or similar flat surface. The front-panel grill shall be formed of precision perforated steel with a diamond pattern that produces a rigidity sufficient to preclude any visual deformation with the application of finger-applied pressure. The grill shall be mechanically isolated from the speaker enclosure. The unit shall be constructed in a rigid steel enclosure compatible with RDL and OEM Decora style mounting rings, boxes of sufficient depth and cover plates. The rear face of the unit shall provide graphical labels identifying wiring connections. Connection to external wiring shall be provided using a detachable terminal block on the rear of the unit. The terminal block shall accept wiring gauges from 14 to 22 and shall include a positive electrically conductive mechanism to prevent wire abrasion by the terminal screws. The unit shall measure 4.1 in. (10.4 cm) x 2.07 in. (5.26 cm), (with terminal block) x 1.72 in. (4.37 cm) and be compatible with all RDL Decora mounting accessories. The unit shall be supplied with two machine screws for Decora mounting. The unit shall be engineered, assembled and tested in the U.S.A. and be specified for continuous duty in professional installed systems. The unit shall be specified for operation in an ambient temperature between 0 and 40 degrees C. The unit shall comply with relevant EMC requirements and shall bear the CE marking. The unit shall be an RDL D-SP1A (white), DB-SP1A (black), DS-SP1A (stainless steel) or DG-SP1A (gray).