ABSTRACT
Modern loudspeaker drivers can handle far greater power and produce much higher sound-pressure levels (SPLs) than early models. Building a single loudspeaker that can cover the entire frequency range of human hearing is a tough call as the requirements for creating high SPLs at low frequencies are very different from those required to reproduce high frequencies. The efficiency of a PA speaker depends both on the driver itself and on the design of the cabinet it is placed in. Passive designs are reliable and cost-effective, but are best suited only to relatively low-power systems, as they are inefficient, with some of the amplifier power being dissipated as heat within the passive crossover circuit. There are also some PA systems that use multiple small cone drivers to cover the majority of the frequency range, although these are usually teamed with a subwoofer where deep bass is required.
