"Checking and Adjusting Guitar Intonation" discussed remedies for strings with bad intonation. This article is concerned with another bane of guitar players: fret buzz. This is a buzzing sound created when a string touches other frets when a note is fretted and played. String buzz can be remedied by adjusting the "action" (string height) or adjusting the "truss rod" (neck relief).
Setting up Guitar Action
The height of strings above the fretboard is a personal aspect of guitar setup. Action can and should be set to what feels right for the guitarist. Too far to either extreme can cause problems, though. If the strings are too high, they are more difficult to fret, slowing down playing. If the strings are too low, it can cause fret buzz. As usual, instructions are given for adjustment on a Tune-o-matic electric guitar bridge. Instructions for other types of bridges can be found online.
A Tune-o-matic bridge makes action adjustment easy. On some models, one simply turns the thumbscrews controlling action for each side of the bridge. On other models, screws on each side are either loosened or tightened. Start with the strings as low as possible, then raise them until the there is no longer any buzz when any note is fretted – this is the minimum playable action. Then the action can be adjusted higher to the player's taste.
How to Set up Neck Relief
The truss rod is a metal rod that runs through the neck of many steel string guitars, both acoustic and electric. The truss rod reinforces the neck, helping it to hold against the strong tension of the strings. Guitar necks are generally supposed to have some amount of bend, or "relief." Too little or too much relief can cause playability issues such as fret buzz, or even damage to the neck itself.
The amount of neck relief needed is individual to each guitar and player, depending on the other aspects of the guitar's setup. Aspects such as string action and string tension/gauge can necessitate needing more or less relief. Truss rod adjustment is one of the last things to try when attempting to set action.
It is important to understand that the truss rod is not meant to, and will not set action. It is meant to hold the neck in place against the pull of the strings. Along with proper action, correct neck relief will help avoid or fix buzzing problems, though.
Checking Neck Relief
Adjusting a truss rod is done by a bolt on the rod, usually using either an allen key or a hex nut. To determine whether the truss rod needs adjustment, fret the low E string at the first and twelfth frets at the same time while looking at the string and fretboard in between the fretted notes from the side.
If there is no visible gap between the string and fretboard, the neck is either bowed backwards or completely flat. If there is a gap, it is bowed forward. Determine whether it is the neck relief that is causing the fret buzz.
Truss Rod Adjustment Can be Risky
Adjusting the truss rod is a last ditch effort that should only be attempted if absolutely necessary because it is a relatively delicate procedure. Tightening or loosening the truss rod too much can cause damage to a guitar. Over-tightening can, in fact, break the truss rod. It is recommended that the guitar be brought to a professional guitar tech., repairer, or luthier who is experienced in servicing guitars. Don't risk damage requiring expensive repairs to fix a small problem.
More Information
Adjusting Your Guitar's Truss Rod
Jeremy Salow - Jeremy is a writer at heart, currently working in the education field as his day job. A 2007 graduate of Franklin & Marshall College, he ...
