Originally Posted by andrewwynn

If the hum changes in left vs right curves very likely wheel bearing. You can't tell left from right side based on which curve makes it sound better because there are four zones of race that are involved (inner, outer, and top and bottom of each).

I've discovered that swapping between 255 and 235 tire will flip the race loading from inner top, outer bottom to outer top, inner bottom and can be a fantastic was to determine which wheel is at fault. It can be painfully difficult to determine which wheel is the cause.

That said, if the sound only is at speed,
You could just have a minor off balance that is finding a harmonic frequency of something