I had a whine/growl in my front end that was more apparent at speeds below 60. It was the right front wheel bearings. The easiest way to determine if it is the right front is to steer a little to the right at about 35 MPH. If the sound goes away momentarily when you do that, it is coming from the right front. You unload the right front bearings momentarily when you cut the wheels to the right thereby causing the sound to stop for that moment. Same theory will determine if the sound is coming from the left by reversing the procedure. I would be surprised if the "whump-whump" is coming from a bearing. Generally, when a bearing gets to the "whump-whump" point, you're not going anywhere.
