I have the same exact light, and while it does make a bit of a buzz, it isn't anything that my furnace blower or a dehumidifier doesn't mask without a problem. But I most certainly wouldn't cover it up with a blanket or anything or you are looking to have some serious fire issues.
TheGanjaKing420 Reviewed by TheGanjaKing420 on . Ballast Noise! I just got the 400 watt hps from htgsupply.com (High Tech Garden Supply) I knew the ballast would make a little noise, and it did for the first few hours it was plugged in, which was fine but then at about five hours the humming started to get way to loud. Is this normal? If so, how do you deal with ballast noise? It gets too hot to just muffle it with a blanket on top. Any ideas? Rating: 5