Guitar Adjustments – Beginners Guitar Lessons Pt13
Intonation is the pitch of all notes over the entire guitar neck. The basic idea of intonation, is that a string’s length from the nut to its center (the 12th fret octave) must be must the same distance to the bridge saddle. If its not, notes higher up on the fretboard will sound out of tune.
Improper intonation can come about when changing string gauges, improper neck adjustments, action set too high, or instrument damage. Since each string is of a different thickness, slightly different lengths are required for the notes to sound true.
Electric guitars are normally fitted with adjustable bridges, allowing individual string saddles to be adjusted accordingly. Most acoustic guitars are equipped with non-adjustable bridges, called compensating bridges, and are pre-set at the factory.
Intonation cannot be accurately determined by ear, so guitar shop personnel use a stroboscopic (strobe) tuner when performing the procedure. The technician frets each string on the 12th fret (the octave) and checks the tuner to determine if the note is sharp (high) or flat (low). If the note is sharp, the technician adjusts the saddle backwards to add length to the string. If the note is flat, the saddle is adjusted forward to shorten the string’s length.
Intonation should be checked as part of your guitar maintenance schedule, particularly when making other adjustments and string modifications. Improper intonation will not harm your guitar or cause playability problems, but will cause the guitar to sound out of tune in the higher note registers.
Unless you own an accurate tuner such as a strobe, and don’t bother fiddling around with your instrument, intonation is best handled by professionals.
Guitar Adjustments – Action
Every guitar player searches for the guitar’s perfect “action” or string height. While this is normally accomplished by adjusting the bridge up and down on electric guitars, or shaving or shimming the saddle on acoustic guitars, it’s not always as simple as that. While lowering the bridge will bring the strings closer to the fretboard, neck or fret misalignment can cause buzzing notes and flat spots.
As with intonation, unless you are prepared to fiddle about for a while, with no positive results guaranteed, these type of guitar adjustments are best left to professionals considering all the variables involved.
Guitar Adjustments – Neck
Neck adjustments are perhaps one of the most important guitar adjustments needed, and should be taken care of before all else. A maladjusted neck will cause buzzing frets, intonation issues, and action problems. Performing string adjustments with a neck out of whack will cause undesirable results, and may make problems worse.
Guitars are usually supplied with a neck adjustment tool, typically a hex wrench, but attempting to adjust a neck on your own can cause disastrous results if done improperly. Guitar necks contain an internal truss rod, which expands or contracts when adjusted, prompting the wood to follow suit. Truss rods can break, sometimes causing wood damage and always causing the neck to adjust whichever way it likes, resulting in very expensive repairs or neck replacement.
A warped neck is when the guitar neck warps upward toward the strings. Frets are pushed up as well, causing the guitar to play badly, sometimes to the point of being unplayable. Warped necks are just plain bad!
A bowed neck is when the neck is bowed away from the strings, which is how a properly adjusted neck should be. If too much bow exists, the action and intonation will be affected, and the guitar will be difficult to play, and can sound out of tune. Bowed necks are good, as long as they are not bowed too much.
A reliable way of telling whether a neck needs adjusting, is not sighting the neck down the center, as many believe. This is okay to do when inspecting a guitar to see if the neck is off-kilter side to side (which is rare), but frets will create an optical illusion, preventing visible evidence of warping or bowing. To do this, look at the guitar fingerboard from the side. Press the low “E” string down on the first fret with one hand, and the last fret with the other hand. If the frets are making positive contact with the guitar strings (indicating a possibly warped neck), or if there is a considerable gap between them (indicating a possibly bowed neck) the guitar should probably be brought in for adjustment. Doing this adjustment check with a straight-edge or ruler of sufficient length is also acceptable, and will actually give you a more accurate indication. The string method is handy when a straight edge is not available.
Hope this clears up some of the mystery of guitar adjustments and terms. A bit of advice: When purchasing a new or used instrument from a store, always ask them to throw in a complete set-up, which will include string change, intonation, neck and action adjustments. If they refuse, and you have to pay a bit for set-up, it’s totally worth the expense. You’ll know that your guitar is starting out its new life properly adjusted, and you will better be able to feel the difference if problems come up.