Why do i hear a cracking nouns from our church speaker whenever i interested the lights contained by the room?
Answers: Electricity, my friend. You probably hear it when you turn off the lights, too.
Check the grounding for your audio beneficiary or amplifier. If it uses a 2 prong plug and is removable (unlikely) from the device, invest in a 3 prong power cord. Otherwise, check the power plug for the speaker and confirm it have a ground, too.
Purchase a surge supressor for the amp/receiver. The electricity is likely cause a surge to the outlet your amp/receiver/speaker hence causing a spike and your speaker is outputting that spike as an audio tone.