Sometimes standard dynamic balancing doesn't get rid of a vibration. Even though the tire/wheel is perfectly balanced, you can get a vibration caused by the belts, cords, and/or tread rubber. I've fixed quite a few tire/wheel caused vibrations in the past by doing a road force balance. Takes a special balancer that not all shops have (mine included) that runs a big drum against the tire to simulate the load of the car driving down the road. It may tell you to rotate the tire a certain number of degrees on the rim and then of course, you add the weights as usual. It's called match mounting when it has you reindex the tire on the rim. Gets the high point of the tire (they all have a high point no matter what price range) to be opposite of the high point of the rim.
If you did a road force balance and then spun the same wheel for a dynamic balance, the machine would show it being out of balance and you need different weight in a different spot.
It's amazing how doing road force balance on tires that have no noticeable vibration and drive the car again. Then you realize it really did have a vibration, just that no one could feel it,,,,,,,,,,,,,until it's gone.
Might be worth a try.
