What’s That Sound? Fret Buzz and Intonation

Updated: Apr 9

You buy a new or used ukulele, your first one ever. Your excitement is through the roof as you can’t wait to begin your ukulele journey. You start perusing the inter-webs for ukulele tutorials and lessons and after watching an avalanche of videos you start hearing ‘buzz‘ words such as intonation and fret buzz. Its like hearing a sommelier wax poetic on the nuances in a glass of wine as they swirl it in the light… only to then rate it one grape out of five. You're frightened as a deep sense of dread envelops you.

”What the heck is fret buzz? Do I have it?”

It’s like catching a life threatening disease the way these ’pro’ level players talk about it. And don’t get me started on the countless sour faces they make when they realize an ukulele has bad intonation.

Its pretty much stage 4 and terminal. Lights out! The worse part is you don’t even know what they are talking about. You try to listen hard for the bad intonation in the video but can’t pick it out.

Have no fear! As your resident ukulele doctor, I’m going to help you diagnose your ukulele!

Fret Buzz

Fret buzz is the annoying sound caused by a ukulele string rattling/buzzing against a fret wire when the ukulele is being plucked or strummed. To diagnose this problem you just have to play up the ukulele fingerboard note by note, string by string. As you do this, listen for any buzzing sounds. Its important to press firmly on the strings between the frets as doing this lightly can give you false buzzing. If your ukulele plays all the way up the fingerboard without a rattle, congratulations! Your ukulele is free of fret buzz. But if you hear buzzing anywhere on the fingerboard…. well, I’m sad to say you got a bad case of the buzz.

There are three things that cause fret buzz.

  1. String Action is too low

  2. Frets are not level with each other (some are taller, some are shorter)

  3. Neck does not have enough "relief" (neck is too straight, or bowing backwards)

String Action

Let's start with string action. String action is the height of the ukulele string measured at a specific fret. It’s common to take string action measurements at the first fret, twelfth fret, and fifteenth fret. Different players will have different preferences for their string action. Some players prefer it being relatively high (people who strum extra hard), while others prefer very low action (those with a soft touch, you jazz players).

There is a threshold to know how low the string action can be set before it starts to create problems. Using a String Action Gauge ruler you can figure this out. If the strings are set too low, the vibration alone will unintentionally rub on frets creating buzz.

Unleveled Frets

The frets on your ukulele are supposed to be level with each other. That means they should all be the same height down the fingerboard. When the frets are not level with each other this means some of the frets are shorter and some of the frets are taller. Though it’s only with the tall frets that we have a problem. When strings rub up against taller frets down the fingerboard it creates buzz. Thankfully though, strings won’t buzz against low frets (a point for us shorter guys, yay). To fix this type of buzz, you have to get the frets leveled. Short or tall, they have to all be the same height! Take it in to a music shop and they should be able to level and re-crown the frets in a couple days.

Neck Relief

A ukulele neck is supposed to be perfectly straight, and yet not quite. Assuming the ukulele is strung and tuned to pitch, it should have a slight dip in the middle (around the 8th fret). It’s called the "neck relief". If a neck has a dip in the middle, we can refer to that neck as having "forward bow". If a neck has no dip at all, but rather a hump, then we can refer to that neck as having "back bow". Back bow is always bad and a deal breaker. It means there is not enough relief in the neck which causes the open strings to buzz on the first fret. Avoid back bowed ukulele at all cost… no matter how beautiful it looks. If your ukulele has a bolt on neck, this can be fixed by changing out the neck. If not, it will make a beautiful and expensive wall decoration!

Though I must confess! As the resident ukulele doctor in the ER, there are a few more reasons for buzzing. Though they are not caused by the frets. One is an easy fix while the other is a death sentence… haha! The buzzing can come from the tuners on the headstock. The washers may be loose, so they rattle when played. To check this, just tap on the tuners where the strings are wound. If you see the washers on one of more of them move, just use a wrench to gently tighten them up. This will stop the buzzing immediately. The other reason your ukulele may be buzzing is that it has an internal problem. These include loose braces and bad installations. Whether they are for pickups, side mounted EQ’s, or strap pins. Those can be fixed with proper reinstallation. But loose braces, there's nothing we can really do. RIP!

Bad Intonation

Intonation is the way that the instrument is in tune with itself, along the entire neck. Intonation is something that affects almost any fretted instrument that has a bridge and strings, and can make a massive difference in the way your ukulele sounds. Making or breaking whether you sound good while playing.

If the intonation on your ukulele is out of whack, you’ll find that the ukulele sounds awful. Even if you tune it 1000 times! This is because fretted notes will sound sharp or flat as the strings aren’t compensating correctly for any tension. This will effect the pitch of the note. Thankfully with ukulele, you don’t find intonation issues until to move quite a way up the fingerboard… where most players dare to venture. So if you don’t plan on holding ‘phat’ chords or shredding up there, no worries. But if you are heading that way on your ukulele journey, good intonation is key.

Checking Intonation

You can test to check whether your intonation is good or bad easily. All you really have to do is play an open string, and then play that same string at the twelfth fret. This is because both of those notes should be the same, but an octave apart. For instance, an open G string rings out an G note, and fretting that same string at the twelfth fret will also play an G note. Just higher up. If you notice that these two notes sound out of tune or dissonant, you're ukulele has an intonation problem. If you have a digital tuner or tuning app on your phone, you can literally see the bad intonation if you have trouble with hearing it. Pros can hear while most of use mortals can’t. So having a tuner handy will help you discover this issue.

If the intonation is truly a code blue, taking it to a professional luthier for surgery is needed. They can do some things to help with the string tension like changing the saddles and refilling the nut grooves. Its so nuanced that you need a pro to handle it as the process is finicky!

But most times, and for most of us, it won’t be noticed. Also a word to the wise. If you're buying an affordable mass market ukulele, odds are your gonna have intonation issues. And if you drop big bucks on a custom high end ukulele you too will have intonation issues due to environmental changes on the ukulele such as humidity. Bad intonation truly is the silent killer!


There you have it! You have the prognosis as well the diagnoses for those strange ukulele sounds. I hope your ukulele is in good health. But if not, a speedy recovery!

Keep jamming and aloha!

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