Bose EM180-LP Edgemax Ceiling LoudspeakerEdgeMax loudspeakers combine bold surface mount performance with stealthy design to shatter the limitations of traditional in ceiling loudspeakers. Patented PhaseGuide technology enables EdgeMax loudspeakers to project powerful, focused sound asymmetrically from the rooms edges to the center. New EdgeMax LP models feature an 80 degree vertical coverage angle for use in rooms with lower ceilings, and their shallow 4 inch backcan is ideal for spaces