hello, i have an excalibur 800 .its a few years old. i recently put on a straight shaft and what a difference.but my question is when i swing the control pod hits me in the back and then i hear a tone in my headphones . is this normal? i tapped on the pod and it causes the headphones to have a tone. i dont remember it doing that before . but maybe it did. i dont remember. any advise would be welcome thanks