Array Speakers project a tighter, more focused sound pattern aimed directly at your audience. One advantage of this approach is that students hear a more balanced sound from the front room to the back. With a tighter dispersion angle, the projected sound won"t bounce off of ceilings, windows and walls. This avoids the creation of unnecessary ambient noise in already loud classrooms. The array speakers are ideally installed in classrooms, computer labs or meeting facilities. Their 30 watts of audio enhancement power can project out to 300 people. Each speaker has spring-loaded wire clips for easy connectability to LCD projectors, whiteboards, cameras, computers, or multimedia players. All three models of the Califone array speakers have a protective steel grille and lightweight construction with rugged fiberglass-reinforced ABS plastic for durability. The PI39 is a wireless and powered array speaker with 16-channel UHF capability for wireless reception. It has include dual _" mic inputs, tone control, duplicated DC functions, dual line-in inputs, and an ability to function as master volume control for other connected speakers. The PI30-PS is a powered, non-wireless array speaker with line-in, mic input as well as being DC functioning with the same signal-to-noise enhancing qualities as the PI39 but without UHF capability. Both the PI39 and PI30-PS have fixed and variable line-outs for daisy-chaining to other wired speakers or a supplemental configuration such as a dedicated assistive listening system for Special Needs students. The PI30-SP is a non-powered, non-UHF speaker that operates on existing power supplied through the speaker wire carrying the audio to provide installation opportunities in previously underserved areas of the school.