SESSION 5: DSP IN LOUDSPEAKERS - PART 1 Signal Processing in Sound Reinforcement Engineering Peter Mapp Peter Mapp Associates, Colchester, Essex, UK Traditionally, there are typically four main areas in which signal processing plays a part in a typical sound reinforcement or PA system. These are: (1) Input signal processing eg pre-amplification and Equalisation (2) Routing and control (including insert of effects processing) (3) System response tuning, including equalisation and signal delay (4) Loudspeaker Processing, eg crossovers, response equalisation/alignment and overload drive protection. Only a few years ago, each of the above processes employed a dedicated processor, however, current DSP capabilities will reduce the box count considerably and indeed it is possible to contain all the above, and even include the mixer all in one powerful DSP unit. As it is anticipated that other papers at this conference will be addressing vocal processing and use of signal processing in studios etc, this paper is more directed towards overall system response tuning and processing. However, processing related t intelligability enhancement is also addressed. Although the paper primarily discusses permanent Sound Reinforcement and Public Address installations, many of the issues also directly relate to temporary sound systems and concert sound systems.