1.) Power on the AV rack by using the button on the top right. Be sure to turn this switch off when finished. Here are three examples of the type of button you may see:
2.) Use the knobs to adjust appropriate source of audio. There are labels for each knob specific to the room.
3) If using a microphone, there is a handheld and a headset available. They are located in the drawer in the AV rack and power on by holding the notated buttons. Hold them again when you are done to power them down.