The only SOURCE of vibrations are ROTATING components, almost always wheel/tires or driveshaft. Vibrations are AGGRAVATED by loose suspension or more commonly steering linkage components.
That said, you have a vibration ONLY at a specific speed (frequency) so it could be a static component such as steering linkage, etc. If the vibration is driveshaft speed rather than wheel speed, it could be a loose carrier bearing or other driveshaft related component.
Since more than 90% of vibration problems on cars are wheel/tire related, you need to ENSURE that the wheels are balanced CORRECTLY. It is all too common for the tire store kids to put wheel weights ONLY on the inboard lip of the wheel saying that customers complain about the ugly weights being seen on their alloy wheels.
It is possible to get lucky with weights only on the inboard, but rare. On all modern cars the suspensions are nimble and REQUIRE dynamically balanced wheels, meaning weights both inboard and out. I have gotten so frustrated with the tire stores that I bought my own Coats computer balancer so I could balance them correctly without having a fight with the tire store kid every time.