Wind chimes?!?

Hello, Im a amature when it comes to Feng Shui, but I had heard that it is a good thing to put a wind chime by the front door, I think to ward off evil spirits. I have done that (well off to the right of the front door) and my wife has some up in front of our kitchen window and rear sliding door. Would having these other two out the back negate the attempts of the one near the front door? Is the one to the right of the front door ok where it is? or does it need to be front and centre of the door frame?
Please dont laugh at my explanations.. I tried to explain my understanding of Feng Shui as good as I could.
Thanks very much.