I recently bought a new racquet, nothing expensive, just to avoid breaking my best racquet when I'm just playing for fun. it's a Wilson federer 110 racquet, it doesn't matter how I hit the ball, how hard I hit it or what balls I use. every time I hit the ball, there is a ping noise from the strings. is this normal? I don't fully understand the difference between different strings or different string tensions, but is this sound normal? if I serve as hard as I can hit or play a gentle drop shot, I hear the same noise from the strings. I never remember this noise with my other racquet or with other people when watching them, so I'm a little lost as to what this could be. can someone please help?