Signal Processors
It is usual to place a Signal Processor between the final mixer stage and the audio amplifier so that final corrections can be made to shape the frequencies of the sound to suit the characteristics of your venue. These corrections are usually based on a profile of your venue taken from a frequency analyser.
This processing can take the form of a simple analogue 'Graphic Equaliser' or a digital processor where the most complex of algorithms can be used to more precisely shape the sound.
The 'Graphic Equaliser' is cheaper and faster to set up but is usually too limited to meet the needs of a challenging acoustic environment.
Digital Sound Processors can meet the challenge posed by most environments but require time and expertise to get the best results.