i had the same problem as you have right now sir..
It constantly irritates me before that whenever our neighbor would do her washing chores and has her washing machine spunning around.. (we live in an apartment unit), somehow my speakers would constantly emit popping sound and its very annoying actually... especially when you're in a mood to listen some good quality musics...
I've already installed a different circuit breaker for my audio/videos setups, even putting 2 AVRs and 2 surge protectors to go along w/ it.. but still didnt fix the problem..
what I did finally was to buy a and line conditioner that has a built in surge protector and that finally quieted my speakers.. it toned down the popping sound that up to the point that i seldom cant hear it anymore...
Jojo