Thank you all for your helpful tips and input. I finally isolated the problem after many days of trouble shooting, aka googling and read on some forums that my mini fridge in my mini bar inside my Bat Cave was triggering the popping/crackle in my system. Every time the fridges compressor came on/off it would cause the pop. I was not aware of fridge since I played my movies at loud volumes. Either way hope this helps everyone else who comes across this issue. Now I have to either move my fridge to another room, bummer or unplug/set temp at zero when using AV System...