This pair of black AC-S4T-BK AcousticCoverage LoudSpeakers from QSC is a set of surface mounted 4" two-way loudSpeakers with 70/100V transformers, suitable for voice paging and background music sound reinforcement applications. 
Each loudSpeaker Features a 4" polypropylene cone transducer with a butyl rubber surround and a 1" aluminum dome tweeter designed to offer clarity through the critical vocal range for increased speech intelligibility. With 130deg. of conical coverage, the AC-S4T-BK reduces the number of loudSpeakers required for even coverage in close proximity. 
The UV treated high-impact ABS enclosure and ported baffle assembly has been optimally tuned for added musicality, creating low frequency extension down to 70 Hz. The AC-S4T-BK utilizes a 16W low-saturation and low-loss 70/100V transformer with varying selectable taps, including an 8-ohm bypass to maintain this frequency response. 
Advanced voicing via QSC Intrinsic Correction techniques are obtainable using Q-Sys networked audio processing platforms, including CXD amplifiers for a complete QSC systems solution. The loudSpeaker Features a 4-pole Euroblock connector for loop thru wiring, located on the rear of the enclosure. The Euroblock can accept four 18AWG pairs. 
The AC-S4T-BK Features brass inserts to accept the included yoke mount, and it is secured using the supplied thumb bolts. The grille has a spring loaded and rotatable logo for installation convenience in either horizontal or vertical deployments. To assist in successful systems integration, complete easE, CAD, and BIM files are available for download online.