Echoing: Happens when both room/ceiling and projector speakers are playing at the same time.
Solution: Turn down projector audio (via remote) or turn down room/ceiling speakers (via AV wall panel or closet amplifier)
Buzzing: Occurs when the amplifier "Master" level is turned up too high.
Solution: Turn down the amplifier in the closest.
Audio only coming out of laptop should be through ceiling speakers
Solution
Sound is still quiet
Solution: AV Panel volume knob