Iwas out on the road recently for some live shows and studio recordings. Within
a short period of time, my guitar went from
its comfy, climate-controlled home into
freezing temperatures hovering around zero,
and then directly down into the heat and
humidity of the Caribbean.
Traveling in planes, trains, and automobiles, my guitar took a beating. As we
prepared for an outdoor show in the sun, its
strings started buzzing so badly on the 2nd
fret, they sounded like a sitar. After looking
online to learn how to do an emergency
tweak, I got through the show. But when
I got back home, the action got so high it
hurt my hands to play this guitar, and I
was unable to record with it. In frustration,
I took it to Rob DiStefano at Fret Tech in
New Jersey. A veteran builder and top-flight
repairman since the mid ’60s, DiStefano
made the neck good as new with a few
twists. While I was there, I asked him how
to deal with this problem if it happens again.
Our conversation went something like this.
What if I’m on the road and the guitar
starts buzzing badly?
Typically, it means that the neck is bowed
up—in other words, the fretboard is arching
higher than it should, which creates a slight
convex curve somewhere in the middle of
the playing area. [This hump is sometimes
referred to as back bow or reverse bow.]
When a guitar is set up properly, the fret-
board has a very subtle concave curve. That’s
called relief, and it provides enough room for
the strings to vibrate freely without hitting
the frets. When the fretboard bows up in the
middle, you have less relief, and this reduces
the angle between the saddle and any strings
pressed against a fret. With a smaller angle, the
strings have more opportunity to touch the
fret in front of it. This contact causes buzzing.
To correct the problem, first you need
to check the neck relief. Here’s how to do
it: Press and hold the low E string at the
1st fret. Then—while still fretting the 6th
string—take your right-hand pinky and fret
this string somewhere just past the 12th
fret. For example, try the fret nearest where
the neck joins the body. Finally, while holding the low E against both frets, bounce that
big E string with your right-hand thumb.
As you do this, notice how much space
there is between the bottom of the low E
and the top of the 7th or 8th fret.
Fret Tech’s Rob DiStefano hard at work in
his New Jersey shop.
When a guitar is set up
properly, the fretboard has
a very subtle concave curve.
That’s called relief, and it
provides enough room for
the strings to vibrate freely
without hitting the frets.
When the fretboard is bowed up, you
might observe a very tiny gap. That’s unacceptable because it’s too small to allow the
strings to vibrate freely while you’re playing. In a worst-case scenario, the strings
will actually be resting against the frets.
Either way, you’ll need to fix the problem
by adjusting the truss rod to add some
neck relief. You want to prevent the big
strings—which make large excursions
when they move—from rattling against
If you’re going to do that, the words to
remember are “lefty loosey, righty tighty.”
In this case, we’re loosening the truss rod
to allow the string tension to pull the neck
forward a little, thus creating a convex
curve in the fretboard.
To loosen the truss rod, insert the
wrench into the truss rod nut and turn
it left—that’s counter-clockwise if you’re
facing the nut. This will relieve some of
the stress on the truss rod and add some
forward bow to the neck. In the process,
you’ll increase the space between the strings
and frets, and thus eliminate the buzzing.
Typically, it takes more than one truss rod
adjustment to get the desired amount of
neck relief. It’s wise to go slowly—1/4 of a
turn at a time.
What does turning it to the right do, and
why might you try that?
Turning the truss rod clockwise—again
you’re facing the truss rod nut—tightens
the truss rod, bows the fretboard up in the
middle, and decreases the space between
the bottom of the strings and the frets. You
do this when string tension has created too
much space between the strings and frets,
making the guitar hard to play.
Neck relief and intonation are two separate issues, right?
That’s right. Neck relief accommodates the
arc of the vibrating strings. Intonation is
changing the length of the strings so that
the open string and the octave of that open
string are in tune with each other.
But you can never really get it perfect,
Fretted instruments are never perfect. We
want a guitar to sound in tune from the
cowboy zone to the shred zone, and guitarists put a large emphasis on chords. To do
this we often have to fudge the intonation
to make it work. So yes, it’s never going
to be perfect, it’s just going to be relatively
good. That’s all you can ask for.
How do either dry or moist conditions
affect the guitar neck?
If the neck is made of wood, it’s going to
swell in humid conditions, and shrink in
dry conditions. This especially occurs to
unfinished fretboards, and also the bodies
and bridges of acoustic guitars.
I often hear people say, “You know, it’s
summertime and always humid, so my guitar
is never going to get dry.” I ask them, “Do
you ever play in an air-conditioned room?” If
they say yes, I explain that an air conditioner
sucks moisture out of the air. Too much
humidity is not nearly as critical as having
no humidity. So if your environment is dry,
try to keep your guitar moisturized with one
of the many commercial guitar-humidifying
products, and use a humidity gauge to monitor the inside of your guitar case.
RICH TOZZOLI is a Grammy-nominated engineer and mixer who has worked with artists ranging from Al Di Meola to Ace Frehley. A life-long guitarist, he’s also the author of Pro Tools Surround Sound Mixing and The Ultimate Guitar Tone Handbook, as well as a composer
for shows such as Fox NFL, Pawn Stars, American
Restoration, and Gene Simmons Family Jewels.