Peavey manufactures a variety of professional sound equipment and electronics. The XR 500C is a powered mixer amplifier, which has diverse applications. Having different inputs and outputs, it can accept a variety of instruments and microphones, and can power concert speakers and monitors. Peavey has an owner's manual for the XR 500C, which details the specifications of the unit.
The XR 500C has five inputs. These can either be a microphone or high impedance musical instrument. Impedance is another word for resistance. It is not recommended to plug in a low impedance instrument. Low impedance instruments are most electric guitars and basses. This will "overload" the internal circuitry, possibly destroying it.
Each input has five controls. One controls the volume of the output. Another controls the reverb level. Reverb, short for reverberation, sends a small time delay in the output signal. This delay is mixed with the original signal. The end effect is the output sounds fuller, like the instrument is being played in an empty hall. Two other controls affect the low and high frequency boost, called the high EQ (equalisation) and the low EQ. The last control is the channel level, which determines how much of the channel's output is fed into the total output signal.
All five channels are controlled by a master control board. Each channel controls the input, and the signal flows to the master control. The master board has three controls, which are Gain, Monitor and Reverb. The Gain and Monitor control the incoming and outgoing volume levels of the master. It also has a Graphic Equalizer. The Graphic Equalizer adjusts the volume of each individual frequency band, such as bass, midrange, or treble. This is useful for fine tuning to sound for every hall or concert theatre situation, since different walls absorb frequencies.
The outputs are very simple. There are two outputs to drive two speakers. An auxiliary output allows the signal to be fed to an external equaliser. From the external equaliser, the signal can be fed to the theatre's main power amplifier, to drive the house speakers.