So where do I get a lesson in how to read these charts anyway... Since it is tested at 87.5, is the line supposed to be as close to that as possible? When it jumps above is that what people call a hump at a certain frequency? And below the line would be a....valley? Their probably not as hard to read as they seem, I just never took the time to try to figure them out, especially when it comes to looking at two different ones and comparing them.