A great guitar setup isn't luck – here's how action, neck relief, and intonation all connect.
Customising your bass or guitar setup can be a beautiful thing. Beyond swapping pickups or simply different strings, you can drastically change the sound of your guitar. Even without affecting the sonics of your guitar, you can fine-tune the feel and playability thanks to adjustable bridges, tailpieces, nuts and necks. The tension of your strings pulls the bridge and headstock closer together, creating a concave in the guitar’s neck. This is offset by one or two metal rods, called truss rods, that run along a channel beneath the fretboard and can be tightened or loosened to counteract the tension of the strings that are pulling at it.
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Bigger or smaller gauges of strings can cause the strings to be closer to the frets themselves, and as such, bridges can be raised or lowered. String size aside, some players prefer their strings closer to the frets, while some prefer them higher. The distance between the frets and strings is called the guitar’s action, and this is set for both personal preference and string gauge.
All of these adjustments are perfect to ensure your guitar or bass feels comfortable to your body, hands, plectrum preference, picking hand intensity and more. However, like any mechanical product, adjustments at any stage of the process affect components both upstream and downstream, which may also require adjustment. These adjustments will potentially also mechanically affect your original settings, and you’ll find yourself in a vicious cycle of moving parts affecting moving parts. To decipher some of this, let’s dive into tuning, intonation, neck relief and its ultimate effect on fretting notes.
Action
As mentioned before, the action is the distance between the frets and the strings. Higher action requires more pressure to fret a note, while lower action requires less. Action is adjusted at the bridge, and raises or lowers the strings at that end of the guitar. Fender bridges often have steel saddles that can be adjusted individually per string, while Les Paul or Floyd Rose style bridges can be adjusted on either side of the bridge, all at once. Some acoustic guitars feature thumbwheels on the bridge to raise or lower it; some acoustic guitars feature a bone or nut bridge that is made at a set height, albeit removable. Raising the action here requires a new bridge, or sanding down the old bridge!
Adjusting the action at the headstock end of the guitar isn’t so easy, as the nut isn’t always so easily adjustable. Minor adjustments to action at the bridge won’t do too much to affect fretting near the nut; however, a major adjustment will cause the strings to sit at an odd angle and might require a new nut or, in the case of Floyd Rose-style locking nuts, a shim can be placed beneath the locking nut.
Larger gauge strings will be better for lower tunings or heavy-handed players, while lighter gauge strings are best for standard or those doing controlled bending that require flexibility and accuracy. The string gauge, as discussed before, affects action and will adjust how much tension your truss rod needs to combat.
String gauge
String gauge can be dependent on two things: preference and tuning. Stevie Ray Vaughan quite famously played .13 gauge strings (referring to the smallest, highest string) in E or Eb Standard, a far cry from the .9 or .10 gauge strings usually recommended for E Standard. Many metal players, and those using extended range, seven or eight-string guitars, usually opt for lower tuning (less tension) and therefore heavier strings to combat that. Some metal player will use a .70 and beyond for their lowest strings, transitioning into bass string territory.
Preferences aside, the bigger the string, the closer it will be to the fret, as mentioned earlier. Bigger strings will require you to raise the action of your guitar, ensuring there’s enough clearance for the strings to vibrate freely without buzzing against the frets themselves. Lower action makes for easier playing, but obviously invites the risk of more buzz. Some buzz is negligible, though other buzz is loud enough to be picked up and amplified, so it will need to be rectified.
The other thing to keep in mind is the radius of your fretboard. Fender’s individual saddle design allows you to raise or lower the action per string, meaning you can maintain the same action despite the subtle curve of the fretboard, usually 7.25” or 9” for a Fender. Les Paul-style guitars and more modern designs have a flatter radius, and therefore don’t require as much fine-tuning per string. As such, many of these designs feature bridges that can be raised or lowered as a whole.
Neck Relief
String clearance above your frets to prevent buzzing is just as important as the neck relief. We discussed earlier that strings add tension to a guitar’s neck, and this needs to be countered by the truss rod that runs along the neck and fretboard. Too much string tension will cause the neck to bow inward, creating a concave shape, and a higher action around the middle of the fretboard versus the first fret and last fret. If the truss rod is doing too much, the opposite will happen, creating a convex shape and a subsequent buzz in the middle of the fretboard, while the first and last frets will be buzz-free. Even tiny inconsistencies can result in buzzing, as fretting a note might cause a fret elsewhere to buzz if the neck isn’t straight. A little concave is okay, sometimes preferable for some players, while even a little convex can wreak havoc on your playing.
To check neck relief, begin by fretting the first fret with one hand. With another hand, press down on the first fret so that the guitar’s body makes contact with the neck, i.e. the 14th on a Les Paul or the 17th on a Strat. In the middle of these two points, usually around the 8-9th fret, there should still be a little gap; slightly smaller than a credit card is perfect. More gap and you’ve got too much concave, no gap and you’ve got too much convex. You can counter this by adjusting your truss rod, usually at either the headstock or sometimes accessible where the neck meets the body.
Intonation
All of these adjustments are also changing the distance between the nut and the bridge. Increasing or decreasing this distance will, albeit subtly, shift the natural ‘middle’ of the fretboard, and therefore the resulting sound made when notes are fretted.
If the distance is too long, i.e. the saddle is too far back, or the action is so high that it’s extended the length of the string, the frets won’t line up with the string’s length and the notes will be flat. Too short a distance and the notes will be sharp.
This is called the intonation, and ensures that both the open strings are in tune, as well as the frets up the neck being perfectly in tune. For this reason, bridges have separate pieces called saddles that can be moved forward or back. Moving them back towards the bout of the guitar increases the length of the string and will counteract frets being too sharp; the opposite if you’re moving saddles towards the headstock and neck end. To check intonation, tune the open string to be perfectly in tune, then fret the 12th fret (an octave) and check its tuning. Too sharp and you’ll need to move the saddle back to lower the note, too flat and you’ll need to shorten the string. Checking the octave generally ensures every fret in between will ring in tune—though remember that the imperfection of it all is what makes a guitar sound like a guitar. A perfectly in-tune instrument might sound more like a synth than a guitar, the subtle rub of strings resonating together offering that profoundly harmonically rich tone we all love so much.
Happy tuning!
