The Buzz on the Buzz

7/28/2019 The Buzz on the Buzz

1/4

The Buzz on the Buzz

By Paul McGill

I think every guitarist at one time or another has a problem with theunwanted phenomenon of instrument vibration. The buzz what is it?Let's describe it as noise made when a vibrating part of the guitarcomes into contact with another part of the guitar, which may or maynot be also vibrating. The resulting sound can have its own frequencyor can become a cacophony of noises not in the control of the player.

What are the most common causes? A list would include: stringcontact with the fret wire on the fingerboard; flatness of the saddle overwhich the strings rest, causing the strings to vibrate; poorly fitting nutslots, which cause the strings to vibrate against or inside the slot; loose

strings or bridge pins; loose truss rod nut; loose or broken top or backbrace; loose truss rod; loose top joint at sides; loose end pin jack nut;vibrating or loose tuning machine parts. Wow, I think I got most of thepotential problems!

How can you determine what the buzz is and where it is beinggenerated? First, does the problem only happen when you play acertain note, or does the problem happen no matter where you play onthe fret board? Most loose parts make noises that are frequencyrelated. Most fret noises or string buzzes are related to the geometry of

the instrument's action setup. The most common buzzes are causedby action problems. Second, you want it to play how low? There arelimits to what can be expected of the action height. However, a well setup instrument can be played with reasonable comfort depending on thedemands of the player.

Let's go through a rundown of a number of indicators for actionproblems and their solutions, and then I will move on to the noisesmade by different body parts.

If a guitar buzzes at the first fret on an open string, the problem is thenut height. Many players want the nut height set very low. The heightof the strings at the nut is usually higher than the fret heights. Onelectric guitars the nut height has to be low as possible for intonationpurposes. However, if the nut height is set low on an acoustic guitar,there can be problems even if the strings clear the first fret. I call thisproblem back buzzing, where a string being depressed higher up thefret board picks up sympathetic vibration and buzzes between the fretsand the strings between the fretted position of the hand and the nut.

Say you are playing a B chord 7th position and the low E string startsrattling behind your hand. If this problem occurs on an electric guitar, it


2/4

has no effect because the pick-up can't transmit the noise given itsposition at the bridge end of the strings. In both cases, either a buzz onan open string or a back buzz on a depressed string, the cure is toraise the nut. You can make a new nut, you can use bone dust or

baking soda with super glue to build up the string height in the nut slot,or you can shim the nut from below. The most elegant cure is a newnut.

Another common problem is fret misalignment. The frets should beplaced in a generally consistent plane, If one fret is to high themisalignment can cause the string to come into contact with that fretwhen playing the note one half step below. Fret noise is a funny thing. Ihave seen guitars where the frets were perfectly aligned, and still therewas noise as if the frets where out of alignment from one end of the

board to the other. Because the problem of string height over a fret isdirectly related to the diameter of the string's oscillation, the height ofthe strings required for noise-free playing can change, given theguitar's scale length and its top stiffness. I had a classical guitar madeby a notable maker in my shop once that would not stop buzzing. Thefrets were accurately aligned, and still it buzzed. This guitar was verylively and had great oscillation of its strings. After much time spentstudying the problem it became clear that the noise disappeared if thenote was played with the finger depressing the string right on top of thefret. If the finger was moved back even an 1/8th of an inch, the buzzreappeared. The strings had so much amplitude that the strings wouldaccelerate right off the fret, causing a buzz even though everythingwas properly aligned. I raised the action, the buzz got worse. Theowner said he liked bass wire on his guitars, so I installed huge basswire in an attempt to eliminate the problem. I was skeptical, but afterinstalling the larger wire, the noise was greatly reduced. It was stillthere if the player wasn't careful, but it was manageable.

Getting back to geometry, if the strings buzz the entire length of the

board the problem is either low action or a saddle buzz. Of course, thatis if the beforementioned acceleration buzzing is not present. If thesaddle is flat on its contact surface with the string, then the squared-offhind edge of the saddle will hold the string's down pressure on thesaddle. The close proximity of the rest of the string's length across thesaddle to the opposing edge of the saddle will provide an area wherethe oscillating string can buzz against the flat saddle surface. The cureis to reshape the saddle, if too flat, or raise the saddle height, if theaction is too low.

The geometry of the action can be greatly altered by whether or not theneck is straight , convex, or concave along the distance of the fret


3/4

board. When the neck is concave or bowed forward in its alignment,the action at the bridge must be lowered so that the strings are not toostiff under the player's fingers. As the strings are lowered the geometryof the action brings the strings into much closer proximity with the frets

further up the fret board. This proximity will cause extra fret noise dueto the action being too low in that area. When the neck is convex orback bowed, the action must be raised to keep the string's proximityacceptable in the central part of the fret board. This misalignment canmake the action height higher up the finger board unplayably high.

Potential action problems are myriad, but I've covered the mostcommon, so I will move on to body noise and loose parts. Most ofthese sounds can be located externally by using your hand to dampena loose part. You should always check the simplest potential problems

first, like a loose tuning machine screw, or even a string end vibratingagainst the guitar. I have seen guitars buzz in some strange placesand have personally been stumped by a few which succeeded inhiding from me for hours while I poked and prodded through the jointsof the instrument until I finally located an ever-so-slight joint failurebetween a top and a piece of lining. Truss rods can make interestingbuzzing noises also. Fortunately, a syringe injection of glue puts aquick end to the raucous tones.

The internal joint failures are more directly diagnosed. You simply use

your knuckles or fingers and tap the top and back plates listening forvibrations or rattles. Braces attached cross grain to a back or top arethe must likely to come loose. This is because the lateral expansionand contraction of these surfaces cause great stress on the glue jointsbetween the back or top and the brace. The action of the back or topattempting to slide back and forth against the brace is not unlikebending a piece of metal back and forth until it breaks. Once located,the loose parts must be reglued from inside the sound box by reachingthrough the sound hole. These repairs can become very interesting on

a mandolin or an arch top guitar where you only have F holes to workthrough. These repairs can require very creative cures at times and arebetter left to those experienced in working inside the body wheresometimes hands must be used as eyes to manipulate the problemareas.

The many causes of unwanted noise on your guitar can sometimes berather pesky to locate or repair. Sometimes they are hard to diagnosebecause of environmental reasons, like the guy who told me about hiscustom made guitar that would buzz in his recording studio. He sent it

back to the factory, but they couldn't locate the problem and returned it.It still buzzed. So this time he recorded the sound of the buzzing guitar


4/4

and sent a tape of the guitar along with it back to the factory. They senthim a new guitar, which he didn't like as well and sold. The problemwas most likely a loose joint in the guitar which would buzz when thehumidity was such that it created less friction between the two parts.

I believe that there is not a buzz which can't be fixed. If one personcan't find it for you, he may be lacking the insight to locate the problem.Hang in there, and eventually these things can come to light.

Documents

The Buzz on the Buzz