The BOSE's FREESPACE DS 40SE is a full-range surface-mount loudspeakers with exceptional performance for background music and speech reproduction in a variety of installation applications. This public address system has a wide coverage pattern of 125° x 125° with a frequency response of 70 Hz, and a single 4.5" (114 mm) full-range driver in a ported enclosure. Horizontal and vertical alignment is possible with adjustable pitch or yaw with the mounting hardware. An integrated multi-tap transformer is incorporated, featuring an ingenious thumb wheel adjustment for quick tap changes from behind the front end cap.