From reading some of the tips that were posted here about humming noise from speakers due to ground loop issue, I was able to finally figure it out its coming from coaxial cable outlet from the wall. I was about to order "ground breaker" from Xantech? through the internet which is $7.45 a piece but they charge over $15.00 for shipping to Hawaii. And some forum member were suggesting you can do the same trick using highend Monster power conditional such as HTS400 and/or HTS850. Does anybody know for sure that humming noise coming from cable coaxial line can be eliminated using Monster HTS400/HTS850? I am currently using the old Adcom AC Enhancer 515 for my HT system along with some inexpensive power strips that you can buy from Home Depot. Any suggestion will be greatly appreciated. I didn't have this problem when I was living at Texas but now my family relocated to Hawaii and this constant humming noise from the speakers are very annoying. But the noise stops when HT is powered down or unhook the cable line from the wall outlet when HT is powered up.