Buzz on the high frets (9-22/4) is generally caused by low bridge adjustment... Buzz on the low frets (1-9) is generally caused by a lack of relief in the neck... relief is the bow of the neck. You can add some relief by loosening the truss rod just a tad to allow the neck to bend just slightly with the tension of the strings... This allows the strings to vibrate on their elliptical pattern without buzzing...