Know Your Gear: Do-It-Yourself Acoustic Guitar Setup

Few things make an acoustic guitarist’s day quite like playing a freshly set up guitar. Suddenly your ax feels like butter. Every string rings like a bell from the first fret up to the neck joint. And the simplest D chord sings like a symphony. You’re reminded why you fell in love with your instrument in the first place.

I’ve done instrument diagnoses galore in my years as a guitar repairman. And it’s safe to say that 90 percent of the instruments—new or old—that come through my hands would sound better and be more satisfying to play with a good setup. A quick setup can unlock tone and playability that a guitar only hints at on the showroom floor. Or, it can put a road-weary instrument back in top performing shape.

Guitars are adjustable instruments, so you don’t have to put up with an instrument that buzzes or is tough to play. Adjustments can—and should—be made periodically to suit your playing style and preferred string gauge. They should also be made to address the changing nature of wood and a guitar’s reaction to string tension and climatic changes.

The definition of “setup” can encompass everything from a change of strings and action adjustment to a much more comprehensive job that corrects intonation, neck angle, saddle height, and more. In this article, I’ll take you step-by-step through a complete setup that includes fine-tuning the action at the nut and bridge, adjusting the neck relief with the truss rod, looking for neck-set problems, and dialing in intonation to ensure your guitar plays in tune all the way up the neck.

If you’re comfortable changing your strings and doing other minor repairs, you can do a basic guitar setup yourself. While you may have to invest in a few simple tools, over the long haul, you can save a lot of dough doing it yourself instead of paying a luthier or guitar repair person. Better yet, you’ll understand the factors that are involved in making your guitar play and sound exactly the way you like.

On a cautionary note, a lot of procedures involved in a setup—like nut filing, saddle shaving, and truss-rod adjustments—can cause expensive damage or require parts replacement if done improperly. So be patient, move slowly and incrementally, and when in doubt, sand, file, or torque a little less than you think you should. Caution and care will save a lot of headaches and help you better understand the setup process.

So let’s get started!

Evaluating the Guitar’s Condition

“The patient” is a nice, simple Art and Lutherie Folk Cedar model borrowed from Sylvan Music in Santa Cruz, California. It’s not unlike many new instruments that adjust to string tension over several months and require a post-build setup. First, I’ll check the overall condition of the guitar, looking for any issues that the customer may not know about that may affect playability or the structural integrity of the guitar? While evaluating the guitar’s overall condition, I’ll check the bridge glue joint, examine fret ends for separation from the slot, and tighten any tuner bushings and screws that have come loose.

I’m “sighting the neck” for issues that might require work beyond the scope of a setup, like warpage (signs of torque along the width of the neck) or separation at the neck joint. I’ll also check the neck relief (the curvature along the length of the neck) to evaluate whether any adjustments are necessary or if it has started to curve excessively to the point of bowing.

Here, I’m pressing down the low E string at the first and 13th frets. This enables me to evaluate the neck relief on the bass side of the fretboard. Look for clearance that ranges from about .020 inches between the bottom of the string and the top of the sixth fret on the bottom E and XX inches on the treble side.

NECK & NUT ADJUSTMENTS

On this guitar, the neck had bowed just a little bit—as evidenced by the higher-than-ideal string measurement—which isn’t uncommon on new guitars. So, I’m cranking the truss rod clockwise about 2/3 of a turn with a hex key to flatten the neck and optimize the relief, or curve, along the length of the neck. On many guitars the hex bolt used for truss-rod adjustment is easy to locate inside the body and just forward of the soundhole. You’ll also see them on the peghead, and some require a standard wrench adjustment.

acoustic guitar truss rod diagram — *Truss rod diagram*

In most cases, some neck relief is desirable to prevent buzz. Truss-rod adjustments can be a delicate matter and most adjustments should be made in small increments of quarter turns and no more than a full turn. You can damage a neck with just a little too much of a turn, so if you have any doubts, don’t do it. You’re better off seeking the advice of a pro.

To check for ideal action at the nut, depress each string in turn between the second and third frets. I’m looking for just a hint of daylight between the bottom of each string and the top of the first fret to indicate that the depth of each string slot is accurate. If there’s no space, the string will buzz against the first fret when played open. If there’s too much, the action will be high, the intonation will be off, and fretting will be more difficult. In this case, the action is a little high for my taste, so I’ll file the slot just a bit.

This is one of my Stewart MacDonald nut-slot files at work. These are made to cut a near perfect-sized, round-bottomed slot that guides and supports the string without binding or causing too much friction. These files come in sets that correlate to standard string sizes, but you can make up for in-between string sizes by rocking them sideways a little bit as you file.

SADDLE ADJUSTMENTS

acoustic guitar setup measuring string height — *Measuring string height*

I’m measuring the action at the 12th fret in preparation for making adjustments to the saddle. For this setup, I’m using my preferred measurements of 3/32 inches at the sixth string (low E) and a bit lower, 5/64 inches, at the first string (high E). These measurements, which are taken from the top of the fret to the bottom of the string using a steel rule, work well for most light- and medium-gauge string sets.

Yeah, I’m lazy when it comes to stringing and unstringing guitars! This is a medium-speed, battery-operated screwdriver with a string winder, which really speeds up the process. But any manual string winder will do and should be a part of your guitar setup kit.

I’m pulling the pins in preparation for removing the saddle. Needless to say, this is an important skill for such everyday maintenance as changing strings. For tight bridge pins, which you often encounter on newer instruments, I use this round-edged set of angled wire cutters to grab the pins and pull them out—taking care not to dent or otherwise damage the bridge. If need be, you can rest the cutter on a small piece of leather on the bridge top and apply leverage to get the pins out. But you can also use a softer, plastic pin puller that’s less likely to damage the bridge wood.

This is a handy old trick that will help you economize on strings and eliminate some headaches. Roll and wrap up pairs of strings while working on the guitar. In addition to saving strings that still have some life, you won’t have a Gordian knot of a mess to untangle when it’s time to restring the guitar.

Removing the saddle is a matter of sliding it out of the slot, or very gently prying it free with a slender, pointed instrument like a needle. I determine how much I want to take off the bottom of the saddle, which will be twice as much as I want the action to go down at the 12th fret. Because I want to drop the treble side more than the bass side to accommodate the thinner string, I’ve drawn a fine-point marker line at a slight angle up from the bottom of the saddle using a straightedge.

Here I’m sanding the bottom of the saddle by gently drawing it across self-stick sandpaper adhered to a flat piece of plate glass. I’ve got 100-grit paper on one side for heavier sanding and 220 for the fine sanding that yields a perfectly flat saddle bottom.

EXTRA CARE

While I’ve got the strings off, I’ll do a bit of exterior and interior inspection. Here I’m checking for loose braces and excessive wear on the bridge plate. In this case I found a small stress crack in the top on the treble side of the soundhole, which I repaired with hot hide glue. But this is the type of fix you should probably leave to an experienced repair person (unless you’re feeling adventurous).

Apart from fretboards drying out—which can lead to shrinkage and fret displacement—finger oils and acids can wreak havoc with the wood over the years, and an oil/wax treatment helps block that chemistry. Beyond prolonging fretboard life, it also imparts a rich look to the wood that just looks nice. Whichever method you choose, be sure to apply the wax or oil to a cloth and apply lightly. Too much oil or wax can leave your fretboard saturated and cause the accumulation of dirt and grime. I like to treat fretboards with either Dr. Duck’s Ax Wax or Howard’s Feed-N-Wax, though a light application of bore oil will do the trick too.

Before I check the action height at the saddle for the last time, I check the intonation by playing a false harmonic at the 12th fret against a fretted note at the same fret. If the fretted note is sharp to the harmonic, I’ll file the top of the saddle on an angle toward the back to slightly extend the playing length of the string. If it’s flat, I’ll file in the opposite direction to shorten the string length. This adjustment affects action, too, so you may need to make very slight adjustments to the saddle height again. Again, remember to be patient and work in very small increments.

Though I trust my ears pretty well on intonation tweaks, I also use this Peterson Virtual Strobe tuner to see a visual representation of what I’m hearing. Using a good tuner will help you nail the intonation and train your ear. I try to adjust intonation ever so slightly flat because players often clamp down the strings hard in the heat of a performance, which can push the notes slightly sharp.

With a little practice, you’ll be surprised how quickly you can work through a setup. As your setup skills improve, you may be inclined to experiment with different setups to better suit your playing. And while you’re likely to save a lot cash by learning to set up guitars on your own (particularly if your collection numbers more than a few instruments) the real payoff comes from having a more intimate understanding of your instrument—a familiarity that, in the end, can make you a better player too.

TOOLS FOR THE JOB

Some tools like the sandpaper and glass you use for shaving a saddle can be found at any local hardware store. Any number of tuners will also work for checking intonation, but you should be sure to invest in one sensitive enough to read the sometimes minute differences between the false harmonic and fretted note that determine whether your intonation is correct.

For other, more specialized tools, Stewart MacDonald (more commonly known as Stew Mac), Luthiers Mercantile International, and Allied Lutherie, are great online and catalog resources. But many good music stores also have these tools in stock. There are also a number of excellent published resources that can be found at bookstores, music stores, and websites that explain the setup process in additional detail.

Here are some tools you will need: