Its hard to know till you heard it a few times. Heard the noise, then heard the system without the noise. Once its gone its sort of an owe wow, I never knew it was so bad. Go to a friend house with a good filter. Have him play with and without. That will get you part of the way to understanding. Of course, some filters may add some ????? But its the general idea. Borrow a filter and put it in your system.