I have a 2001 Oldsmobile Aurora V6. I am concerned with a noise only audibly noticeable when I hit 30mph, it can best be described as a low, rough hum. As I increase with speed the noise becomes faster and less rough but still audible. I think that it might be the final drive, as it doesn't sound as if it is coming from the tires. However I am not sure about either of those.
An easy test and one I use in the shop to determine what bearing is making noise is to put the vehcile on hoist, in neutral, spin tire by hand while grasping coil spring with other hand, should feel smooth if ok, a bad bearing you will be able to feel the roughness/grinding in the spring while spinning the tire