Rattling sound

My car recently got aligned and I had a little problem with my front end vibrating. I got car aligned and two new front tires as the inside of tires were bald. However, problem did not go away. I can not necessarily feel the rattle in the pedal or steering wheel it feels like it is lower then the steering wheel. I took it and got it looked at and they said my tires and brakes look good as new. Could this be a rotor problem? I noticed my guard is a little loose near jack point. Could it be this? Or does it sound like something else like loose sway bar, control arm, or ball joint. It happens mostly when braking.