Tires: Tire vibration

Question
Have a 2003 Toyota Highlander with standard tires.  They are balanced, and recently had alignments done on all the tires.  When driving faster than 60 mph, I get vibration through the steering wheel and a shimmy and can feel some vibration through the floorboard.  Also, around 50 mph and above, there is a distinct "whump-whump-whump" sound from the tire(s). It is especially noticeable when passing other cars, or driving along side a barrier, bridge, divider, etc.  Always checking the air pressure, but it pulls to the left. My initial thought is that one or more tires is/are out-of-round. Your advice?

Answer
Owen,

Rotate your tires.  If the vibration doesn't change, then it is likely there is something in the vehicle vibrating - not the tires and wheels.  

If the vibration changes, then you'll know which pair of tires or wheels might be involved and you can take it from there.

I'm going to guess:  The rotation is not going to change the vibration as you already feel it through both the steering wheel (front tire) and the floorboard (back tire), and odds are against there being 2 tires with an issue.  If this is the case, then you need to have someone look at the vehicle and see what is going on.  It might be U joints.