All fan rating are not created equal. I dont know if manufacturers are just stupid or lie. I have not heard the RS ones you are talking about, but I cannot hear mine unless I get about 2-3 feet around my equipment. I watched a few movies in a row the other weekend and the fan on my amp (adcom) was starting to get a little more audible, but if you had doors on the front of your entertainment center...nothing would be heard!