Why do i hear a cracking sound from our church speaker whenever i open the lights in the room?

Question

Why do i hear a cracking sound from our church speaker whenever i open the lights in the room?

Answer 1

Electricity, my friend.  You probably hear it when you turn off the lights, too.

Check the grounding for your audio receiver 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 has a ground, too.

Purchase a surge supressor for the amp/receiver.  The electricity is likely causing a surge to the outlet your amp/receiver/speaker hence causing a spike and your speaker is outputting that spike as an audio tone.