The loudspeaker system is a critical part of any public address installation. All too often it is woefully inadequate, resulting in poor intelligibility and unnatural reproduction. This book examines the various systems and their drawbacks, and describes LISCA, the line-source ceiling array. This gives astonishing clarity, even coverage, reduced feedback, natural source location and even a pseudo-stereo effect. It promises to be the ultimate system for small to medium sized halls, full step-by-step constructional and installation details are given. Also dealt with are low-impedance matching 100V systems, transmission lines and how to design and install inductive hearing aid loops.