At one time or another it has happened to most of us. You hit that one note and … there it is, that buzzing sound of the string bottoming out on the fret. Usually it’s something that’s simple to fix, like a bad string or maybe the action is set too low; but it could be something more serious like a bowed – or God forbids – a warped neck. Whatever the problem, we’re going to look at the common causes for this problem and how to fix fret buzz.
Buzzing is Bad … Unless You’re a Bee
So, what is fret buzz anyway?
If you are new to playing guitar, you might not yet have experienced fret buzz or really know what it is. When you (or someone else) is playing guitar, sometimes it’s the subtle things that make a real difference. It doesn’t take a really bad buzz to make a whole lot of difference – and in the process take a whole lot of enjoyment out of playing. For a good demonstration of what fret buzz sounds like.
WHY DOES THIS HAPPEN?
There are a number of reasons frets can buzz. Some are easy to detect and fix while others may take some detective work and are harder to remedy. The main reasons for fret buzz in order from easiest to hardest to repair are:
1. Old Strings
Strings lose their elasticity as they age and if you don’t change your strings often enough you may encounter string buzz as a result – particularly if you do a lot of bending or use the whammy bar frequently. Repeatedly stretching the strings and then letting them return them to their original position will cause them to go slack as time goes on.
An early symptom of this kind of problem is encountering problems keeping the guitar in tune. If you are encountering problems with fret buzz and it’s been a while since you’ve changed your strings, that’s probably the best place to start. Not only might it fix your fret buzzing problem, it will definitely improve your sound. This video explains how fret buzzing can be caused by old strings and how new strings will improve your sound.
2. Action Too Low
This problem is a bit more difficult to detect as it requires you to determine where the buzz is coming from. If the buzz is occurring only on the higher (closer to the headstock) frets, the problem is likely that the action is too low. The action at the 12th fret of an electric should guitar should be approximately 1/16th of an inch (see Figure 2 below).
You may ask why this is happening now when it never happened before. Sometimes the answer is as simple as the fact that you switched to a thicker gauge of strings. When I switched from .009s on my guitar to .010s, I developed a slight buzz at the second fret. All I had to do was raise the action just a fraction and the buzz disappeared.
Raising the action is a simple fix provided you exercise patience and employ a few simple tools to do it right.
3. Bad Nut
The slots in bone and especially plastic nuts are susceptible to wearing down over time (see Figure 1 below).
Bad nuts are usually fairly easy to detect. Extensively worn slots can easily be seen with the naked eye, while less worn slots may need to be with examined with a magnifying glass. If the slot becomes too deep, it can lower the action enough to cause fret buzz. This is not an issue for graphite, brass or locking nuts which don’t wear down like softer material.
In this case, the only solution is to replace the nut, but that is not a particularly difficult task if you know what you’re doing and exercise the proper care.
4. Popped Frets
A “popped” fret occurs when the fret raises up higher than the surrounding frets causing the string to catch on that fret. The degree to which it is raised can be either extreme or barely noticeable, with the latter case being more common.
It is a problem you may encounter at some point, but it usually happens only with older guitars or ones that have been subjected to sudden changes in temperature and/or humidity resulting in movement of the fingerboard wood. There is a simple way to check for a popped fret and it is possible to repair yourself:
- Use something with a straight edge such as a credit card or a gift card and place the edge or the straight edge, long side on over the first three frets.
- Check to see if the straight edge pivots over the middle fret or if there is a gap beneath the first or third frets.
- Repeat the process moving down the fretboard, three frets at a time. If you are using a credit card, you’ll have to switch the card to short side down so it covers just three frets at a time.
- Perform this process on both the top and bottom sides since it’s possible that a fret may be properly seated on one side and popped on the other.
- If you detect any gaps or the card pivots on a high fret, you will need to reseat that fret.
Frets can be easily damaged, so if you have any doubt about your ability to work on your guitar, or if it is a very expensive model, it’s best to have a professional look at it. Having a fret professionally reseated is a lot cheaper than having to have the entire guitar refretted because you messed something up.
5. Bowed/Humped/Warped Neck
This is another problem that can be difficult to spot depending on the degree of bowing or warping. Extreme cases can be spotted right away by just sighting down the neck. If the bow/hump is slight, it may come down to a case of eliminating all the other possibilities before determining that a bow or warp is the issue.
For simple bowing issues, the average guitarist can usually fix it by adjusting the truss rod. The adjustable truss rod is designed to correct slight bows in the neck by flexing an adjustable steel, aluminum or carbon fiber rod embedding in the neck.
Truss rods can only fix so much. Severe bows and/or warping (anything more than about 5/8 inch gap between the fretboard and strings) will need to be looked at by qualified repair person, and the neck might have to be completely replaced by a professional.
To determine if the truss rod needs adjustment:
- Take a long straight edge such as a yardstick or specialty notched straight edge and place it edge on along the centerline of the neck (see Figure 4).
- Look to see where the straight edge is contacting the frets. There should be a slight dip in the center of the neck (usually about 1/16 inch at the 12th fret, but it could be a bit higher or lower depending on where you set your action).
- If the dip is too severe, you may actually be experiencing fret buzz at the top and bottom of the fretboard instead of in the middle.
- If the straight edge contacts the frets in the middle, you have a bow in the neck and you’ll need to add relief rather that remove it.
This table gives a brief description of the issue, cause for the buzzing, and how to detect the issue.
HOW TO DETECT
Old or bad strings that are no longer elastic and buzz against the frets
Visible rust or corrosion, unwinding of wound strings, dead strings, buzzing along the entire length of string
Action too low
Strings too low over the frets bottom out on one or more frets
A buzz occurs, usually more noticeable closer to the nut where the action is naturally lower
Worn nut slots, usually due to normal wear and tear over time, allow string action to lower causing buzzing, usually more common at the top of the neck
Badly damaged nuts can be detected visually without magnification, however, less badly damaged nuts may require closer inspection. Buzzing usually happens closer to the nut
Fret becomes unseated and protrudes above level of other frets
Fret buzzing will occur at a specific fret and possibly the frets immediately adjacent. Often the problem can be detected visually.
Neck bowing or humping
Neck takes on a bow or hump causing fret buzzing near where the relief is the lowest
Fret buzzing will occur in areas where the relief (space between the string bed and fretboard surface is the lowest. In case of a bow, where the neck dips in the middle this will be at the upper and lower ends. In the case of a hump, where the neck is higher in the middle, the buzz will be near the middle of the neck.
OK, HOW DO YOU FIX THESE PROBLEMS?
The answer to this depends on what happended with you. For example, if the issue is old or damaged strings, the solution is as simple as buying and installing a new set of strings. If the problem is caused by something else, you may have to have a few specialized tools.
1. Low Action
1.1. What will you need first?
If the action is too low and needs to be raised, depending upon what kind of adjustment screws your bridge has, you’ll need:
- Appropriate screwdriver or Allen wrench on hand to raise the saddles.
- Radius gauge that matches the radius of your neck. You can get a full set of radius gauges, along with some other handy lutherie tools here.
- Ruler marked in 1/16th inch increments.
1.2. Raising the Action
One thing to remember when raising the action is that you never want to raise the action on just one string. You should always raise the action on all of the strings to maintain the proper radius across the strings. An excellent video tutorial for raising the action can be found here.
- If you have a locking nut, remove the locking lugs using the appropriate Allen wrench.
- Determine which string(s) are buzzing. This should be fairly easy to determine by playing each string in sequence.
- Loosen, but do not remove the strings.
- Starting with the string that is buzzing, use the wrench or screwdriver to raise the saddle on the bridge.
- Retighten and play the string about each quarter turn of the screw. Keep track of how many quarter turns you apply. As soon as the string stops buzzing, you can stop.
- You must now raise each remaining saddle to the same height by applying the same number of quarter turns to each of the saddle screws.
- To ensure the most precise adjustment, you can use an under-the-string radius gauge to check that you have the proper radius curve. If you are not sure what your fingerboard radius is, most manufacturers have that information on their website. Fretboard radii can vary widely. A 2017 Gibson Les Paul, for example, has a radius of 12 inches. My 1986 B.C. Rich ST3, on the other hand, has a radius of 8 inches.
2. Bad Nut
2.1. What you will need?
- A replacement nut (I recommend a Graphtech nut which is available for a wide variety of makes and models and is relatively indestructable)
- Chisel or nail set
- Utility or X-Acto knife
- Mineral spirits or acetone
- White or “hide” glue
2.2. How to replace the bad nut?
Replacing a guitar nut may seem like a daunting task for the inexperienced, but with proper care, it’s not something the average guitarist can’t handle.
First and foremost, you must purchase a replacement nut. It is extremely important that you get the proper nut for your make and model. A Fender Stratocaster nut which actually fits into a narrow slot cut into the top of the fingerboard, while a Gibson Les Paul’s nut butts up against top edge of the fingerboard (see Figure 11 for illustration). There are dozens of potential variations. If you cannot find a nut that is an exact fit for your model, you may have to resort to machining your own nut using a similar nut or a bone “blank”. This is a tedious process and would better be left to someone who has more experience in this area or a qualified repair person
- Remove the guitar strings.
- To remove the old nut, place the guitar on a non-slip surface and place a rolled up towel beneath the neck to support it.
- Place the edge of a chisel or nail set against the end of the nut. It doesn’t matter which end you choose.
- Tap lightly with a hammer until the nut pops loose. It should come out with a little gentle persuasion. If it resists coming loose you may have to hit it a little harder. If it still won’t loosen, it’s probably better to bring it to a repair person, because if you hit too hard you may damage the neck or break the nut into pieces which will then need to be cleaned out with specialized tools.
- Once the nut is dislodged. Make sure the nut slot is cleared of any old glue residue. You can use a utility knife of X-Acto knife to clear out the residue. Wipe it clean with mineral spirits or acetone.
- Apply a small dot of glue on either end of the nut. You don’t need much, just enough to hold the nut in place.
- Center the nut and allow glue to dry for 20 minutes or before restringing the guitar and tuning it.
3. Popped Frets
3.1. To fix popped frets, you will need:
3.2. Reseating Popped Frets
If you have detected the popped fret(s):
- Place guitar on a non-slip surface and remove the strings.
- Support the back of the neck as fully as possible using a rolled up towel placed length-wise beneath the neck. Using a fretting hammer, tap firmly along the length of the fret to reseat it. DO NOT use a regular steel hammer because it will likely damage the fret, at best. In a worst case scenario, you could crack the neck. Check the video below to know how to use a fretting hammer to reseat
- Mask off the fretboard with painter’s tape or masking tape leaving only the frets exposed. I like painter’s tape because it’s more durable than standard masking tape.
- Using a fret crowning file you’ll need to recrown any frets you had to reseat. This video below demonstrates the process of recrowning frets.
- Restring and tune the guitar.
4. Neck bowing or humping
4.1. To adjust your truss rod, you will need
- A straight edge at least as long as your fingerboard
- The appropriate wrench for adjusting your truss rod
4.2. Adjusting the Truss Rod
To adjust the truss rod:
Loosen, but do not completely remove the strings.
Remove the truss rod adjustment cover. On most guitars, this is directly behind the nut, but on some guitars, most notably some Fender models, the truss rod adjustment is located at the heel. For those guitars with truss rod adjustment at the heel, you will need to remove the strings and unbolt the neck from the guitar.
To correct a bow in the center of the neck, the most common cause of fret buzz, use the adjustment tool to carefully turn the adjustment nut or screw counter-clockwise a quarter turn at a time. Check the neck with the straight edge each quarter turn until you see a gap of about 1/16th inch appear.
To correct for too much relief, turn the nut or screw a quarter turn clockwise a quarter turn at a time. Check the neck with the straight edge each quarter turn until you see a gap closes to about 1/16th inch. You can find a good video on how to adjust your truss rod here.
Wrapping It Up
Hopefully you found this how-to instructional and feel capable of taking on the task of addressing fret buzz should it become an issue for you. If you have dealt with fret buzz in the past and have any additional tips that I may have left out, please feel free to leave a comment. I hope you enjoyed the article and look forward to the next one. Until then, keep rocking.