Anyone have experience with subj? Got the following problem - I have air intake machine installed in my place. The noise level in the bedroom is pretty low - around 30dbA with intake fan on and 29dbA with intake fan off. The problem is that it seems like I can hear fan blades cutting air noise through air duct which prevents me from falling asleep with working air intake system on. So I am searching for a way to get rid of that noise or at least lower it and making it less annoying.