ABSTRACT
This chapter provides broadcasting engineers with information on how processors work, some pitfalls to avoid, and how to put processors to best use. The most fundamental job of a transmission audio processor is to prevent peak overload of the output channel. One of the biggest challenges in transmission audio processor design is simultaneously controlling peak levels and the spectrum at the processor's output. Processing for two-channel stereophonic transmission is similar to processing for monophonic transmission, except that two audio processing chains are used. The requirements of the transmission service determine how gain-controlling elements should be coupled. In FM stereo transmission, increasing the L-R level increases multipath distortion. The transmission engineer is primarily concerned with the peak overload level of a transmission to prevent overloading. One of the main uses of audio processing is to increase perceived loudness within the peak modulation constraints of a transmission channel.
