Setup and repair
Fret buzz.
Buzz is not a fault, it is information. Where it happens tells you what is wrong, and once you know how to read it you stop guessing and start fixing the actual problem instead of the one you assumed you had.
The short version
Fret buzz is the string touching something on its way to vibrating freely. That is the whole of it. The skill is working out what it is touching, and the answer is written in where the buzz happens.
People almost always skip that step. They hear a buzz, raise the action until it goes away, and call it fixed. It is not fixed. It is hidden, and now the guitar plays worse than it needs to for the rest of its life.
Buzz in the first couple of frets, buzz in the middle of the neck, and buzz at one single fret are three completely different faults with three completely different fixes. If you adjust the wrong one you make the guitar worse and you still have the buzz. So diagnose first. It takes two minutes.
First question: does it even matter?
Here is the thing almost nobody tells you, and it will save some of you the entire job.
A magnetic pickup does not hear your guitar. It reacts to a steel string moving through a magnetic field. A small amount of buzz that is perfectly audible with your ear against the instrument may not make it into the signal at all.
So play the buzzing note unplugged, then plug in and play it again at a normal volume. If it disappears through the amp, you have a decision to make rather than a problem to solve. Plenty of professionally set up guitars with genuinely low action buzz a little acoustically. That is the trade you make for low action, and most players take it happily.
Where it does matter is if you play unplugged a lot, record acoustically, or the buzz is bad enough to choke the note or kill sustain. A note that dies early or goes dull is not cosmetic buzz, that is the string being genuinely obstructed, and that one you fix.
Second question: is it actually the frets?
A surprising amount of what gets called fret buzz is not coming from the frets. Before you start adjusting a truss rod, rule these out, because they are quick and they are common.
| Suspect | How to check it |
|---|---|
| String behind the nut | The length between nut and tuner post can rattle sympathetically. Press it with a finger while the note rings. If the noise stops, that is your culprit. A bit of foam or a string tree sorts it. |
| Pickup too close | A low string with a wide swing can slap a pole piece, especially on the neck pickup up around the twelfth fret. Drop the pickup a couple of turns and play it again. |
| Loose truss rod nut | A rod with slack in it can buzz on its own inside the neck. Usually sounds like it comes from nowhere in particular and often changes with a light tap on the headstock. |
| Loose hardware | Tuner bushings, saddle height screws, spring claw, jack nut, pickguard screws, the tremolo arm. Any of them will rattle in sympathy with certain notes and sound exactly like buzz. |
| Springs in the trem cavity | Very common. Sounds like a metallic ring more than a buzz. A strip of foam under the springs kills it and does not affect anything else. |
Real fret buzz is note specific and position specific. It happens on particular notes in particular places, every single time, repeatably. If a noise shows up on random notes, or changes when you touch a part of the guitar that has nothing to do with the string, it is a rattle, not a fret problem.
The diagnostic: where it buzzes tells you what is wrong
This is the part worth learning properly. Play up each string one fret at a time and note exactly where the buzz starts and stops.
| Where it buzzes | What that means | The fix |
|---|---|---|
| Open strings only, stops as soon as you fret anything | Nut slot cut too deep. The open string is sitting on the first fret. | Fill the slot or replace the nut. Nothing else will do it. |
| First three or four frets | Nut slots slightly low, or the neck has gone back bowed with too little relief. | Check relief first, since it is reversible. Nut second. |
| Middle of the neck, roughly frets 5 to 9 | Not enough relief. The neck is too straight and the widest part of the string swing is hitting the middle frets. | Loosen the truss rod a little to let relief back in. |
| Everywhere above about the 12th | Action too low at the bridge, or the neck needs a touch less relief so the upper register sits right. | Raise the saddles slightly. Small moves. |
| One specific fret, same one every time | A single high or worn fret. No setup adjustment fixes this. | Level that fret, or a full level and crown. |
| Everywhere, all strings, all positions | Action is simply too low for how hard you play. | Raise the action, or lighten your attack. |
| Only when you dig in hard | Normal physics. Strings swing wider when hit harder. | Nothing is broken. Raise it slightly if it bothers you. |
| Appeared with the seasons | The neck has moved with humidity. Wood does this. | Adjust relief. Expect to do it twice a year. |
Two rows there are worth dwelling on, because they are the ones people get wrong most often.
The single fret
If one note buzzes and the notes either side of it are clean, stop adjusting things. You have a high fret, and a truss rod cannot fix a fret that is taller than its neighbours. I have watched people chase this for weeks, cranking relief in and out, raising the action higher and higher, when the actual problem was one fret sitting a couple of thousandths proud.
You need something dead straight that spans three frets. A proper fret rocker is the tool for it, but the edge of a steel rule works if it is genuinely straight. Sit it across three frets at a time and try to rock it. If it rocks, the middle fret of those three is high. Work your way up the neck doing that and you will find it.
Do this with the strings off or pushed aside, and do it in a few places across the width of the board, because a fret can be high on one side and fine on the other.
A single proud fret can sometimes be tapped back down if it simply was not seated, and a drop of thin superglue will hold it. More often it wants levelling, which means taking the tops of the surrounding frets down to match, then re crowning and polishing them. That is proper fretwork, covered in the neck and fretwork guide.
The middle of the neck
Buzz across the middle frets is the classic relief problem, and it is the easiest thing on this page to fix. A plucked string does not travel in a straight line, it swings in an arc, and that arc is widest around the middle of its length. A dead flat neck gives that arc nowhere to go.
A very small amount of forward bow, the relief, gives it clearance. Too little and you buzz in the middle. Too much and your action goes high in the middle and notes fret sharp. There is a right amount and it is smaller than most people think. The measuring method is in the setup guide.
The order to work through it
Do it in this order or you will do it twice, because each step changes the ones after it.
- Fresh strings, the gauge you actually use. Old strings are uneven and buzz for their own reasons.
- Rule out rattles from the table above. Two minutes.
- Set relief with the truss rod.
- Check the nut slots.
- Set action at the bridge.
- Only now, if buzz remains at specific frets, look at levelling.
- Reset intonation, because everything above changed it. See the intonation guide.
Adjust the rod, retune, play it, and listen before you touch anything else. People who move three things at once and then cannot work out what happened are the reason simple setups turn into all day jobs.
And give the neck time. Wood does not move the instant you turn the rod. An eighth of a turn, then leave it and come back.
The myths, straight
"Buzz means it is a cheap guitar"
No. Buzz means it needs setting up. I have had expensive instruments come in buzzing on every string and cheap ones that played beautifully after twenty minutes of work. Factories set instruments up to a generic spec in a controlled climate, then ship them across the world into a different climate. Of course the neck moved. That is not a quality problem, it is a maintenance reality that applies to every guitar ever made.
"You need a refret"
Almost never, and this is the one that costs people the most money. A refret is for frets that are worn out through their useful life, deeply grooved, or lifting. Most buzz is relief, nut, action, or one high fret, and a level and crown handles the fret cases at a fraction of the cost. If somebody quotes you a refret for a buzz without measuring anything first, get another opinion.
"Just raise the action until it stops"
That is not a fix, that is a workaround, and it charges you comfort for the rest of the instrument's life. If the cause is one high fret, raising the action means raising it enough to clear that one fret, which means every other note on the neck is now higher than it needs to be. Fix the cause and you get the low action back for free.
"The truss rod controls the action"
It does not, and this misunderstanding damages more necks than anything else. The truss rod sets relief, the small bow in the neck. Action is set at the bridge. Using the rod to chase string height means fighting the neck into a shape it should not be in, and eventually something gives.
"A little relief is bad, the neck should be dead straight"
A dead straight neck buzzes in the middle for the reason described above. You want a small, deliberate amount of relief. Straight is not the goal.
"Heavier strings will stop the buzz"
Sometimes, accidentally, and not for the reason people think. Heavier strings run at higher tension, which pulls more relief into the neck, which can clear a middle neck buzz. But you have just changed your relief by the crudest possible method, and you also changed your intonation and your feel. If you want more relief, turn the rod.
The things people do not tell you
Two players can pick up the same guitar and one of them buzzes on everything. Attack strength, how hard you fret, whether you pull the string sideways when you bend, all of it changes how much clearance you need. There is no universal correct action height, only the right height for your hands. A setup done to somebody else's numbers is a setup done for somebody else.
Buzz that only appears when you are plugged in and loud is usually not the string at all. It is something on the guitar or nearby resonating with the amp. Chasing it at the frets will get you nowhere.
A nut slot cut at the wrong angle buzzes even when the depth is right. The string should break cleanly over the front edge of the nut, the edge nearest the fretboard, and sit down into the slot behind it. If the slot is flat or angled the wrong way, the string rests on the back edge and rattles in the slot. Same symptom, completely different fix.
New guitars often buzz after a few weeks and this alarms people. The strings settle, the neck settles into your climate, and the factory setup drifts. It is normal and it is not a defect. Give a new instrument a month, then set it up properly.
Buzz that moves around from week to week is almost always humidity. If your guitar is fine in summer and buzzes in winter, or the other way round, the neck is breathing with the seasons. A case humidifier stabilises it, and a small seasonal relief adjustment is simply part of owning a wooden instrument.
When you should stop and hand it over
Most of this is genuinely doable at home with patience and a couple of cheap tools. A few things are not, and knowing where the line is saves instruments.
- A truss rod that will not turn, or feels like it is about to strip. Stop. Do not lean on it.
- Frets lifting out of the board rather than sitting proud.
- A twisted neck, where one side has more relief than the other. That is not a rod adjustment.
- Anything needing a nut replaced, unless you are set up to cut slots properly. A badly cut nut causes more problems than the one it solved.
Everything else is a truss rod, a saddle screw, patience, and knowing what the buzz is telling you.