Audi-A4-3.0TDI

My Audi A4 B8 3.0TDI Tiptronic Quattro, has a womp womp womp noise and vibration coming from the somewhere in the front end drive train, there is no play in the Wheel bearings and none in the front half shafts, All brake discs were replaced 2000KM ago can heard more clearly on Smoother road surfaces and can't be heard below 20km/h and above 90 km/h. Has anyone experienced this? Any help would be Apreciated thanks.