1998 Oldsmobile Bravada front drive

Bought the car 1 month ago. Had the front lined up. Was told lower ball joints had to be replced. I replaced the balls and the bearing hubs at that time and was able to get it a lined. Had tires replced. How I here a noise in the front, its like a hum-hum, when I get above 40 and get worst at higher speed I cannot tell if it is bearings or gears or cv shafts.