[Manny_boy]

Check for the obvious things first, badly worn or uneven brake pads, warped, uneven rotors, stuck or frozen caliper, loose caliper brackets.

If those check out, look for the not so obvious. Do you have aftermarket wheels or larger than stock tires? How tight are your lugs? (it can have an effect on your rotors). You may also have a bad hub.

Block the rear wheels and raise the front wheels off the ground, and remove both tires. See if you can recreate the noise.