October 8th, 2011 9:32 pm
Have you ever had a guitar or bass that didn’t rather play in tune no matter how a heap of times you tuned it up? If so, it is rather possible that your instrument’s intonation is incorrect. If you’ve never heard of intonation, read further because it may be the key to making your instrument play in tune. This article will talk about what intonation is, why it needs to be set properly, how to read it and how to make basic adjustments to your instrument’s intonation.
What is Intonation?
(Please follow the link at the bottom of the article to view the affiliated figures)
The intonation of a guitar or bass has to do with how accurately the instrument voices it is notes. A utterly intonated guitar or bass will play all of it is notes with perfective accuracy. An A will be precisely 440hz, and the octave of that A will be incisively 880hz, no matter where it is played on the fretboard. A guitar or bass that is not the right way intonated may still sound a perfective A in the open position, but play an A in any other position and it will be more or less out of tune.
On a in the right manner intonated guitar or bass, the length of the string amidst the nut and saddle will be more or less longer than the instrument’s stated scale length (the theoretical distance from the nut to the saddle). As you fret a string to sound a note it stretchings a little, causing it is pitch to go more or less sharp. To counteract the change in pitch caused by the stretch, the saddle is placed somewhat further back from the fretboard, efficaciously increasing the length of the string and letting down the pitch. This extra distance the saddle is placed beyond the scale length is called compensation.
A string under lower tension will stretch more than a string beneath higher tension and will require more compensation to be in the right manner intonated. All things being equal, a guitar or bass with high action, a high nut or lower tension strings will require more compensation than an instrument with low action, a short nut or higher tension strings.
Checking the Intonation of Your Instrument
To see if the intonation of your instrument is set properly, you will primary need to obtain a good quality chromatic tuner. You must spend at least $20 on a tuner that you intend to use for reading and setting intonation. A cheap, non-chromatic tuner may create readings that are inaccurate. If you are reading the intonation of an electric instrument with more than one pickup, plug the tuner into the instrument, make sure the volume and tone controls are turned all the way up and that only the pickup nearest the fretboard is turned on, then follow the steps below:
1. Tune the instrument to pitch.
2. Play the harmonic at the twelfth fret of the low E string and note the reading of the tuner.
3. Now fret the string at the twelfth fret, play the E and note the reading of the tuner.
4. If both the harmonic E and fretted E are incisively in tune with each other, the E-string is the right way intonated. If the fretted E is not in tune with the harmonic, the string is not decently intonated and the instrument requires adjustment.
5. Repeat for each string.
Setting the Intonation of Your Instrument
If you’ve never had your instrument set up or intonated, there is a good probability that it is intonation is off. If you have an instrument with saddles that adjust forward and back from the fretboard, similar to those pictured in Figure 1, use the following procedures to adjust your intonation, other than as supposed or expected skip to “Adjusting Intonation with Fixed Saddle(s)”.
Note: If you are doing a full set up on an instrument, do not adjust the intonation until all other adjustments have been made first.
Adjusting Intonation with Moveable Saddle(s)
1. Tune your instrument and read the intonation of the low E-string.
2. If the E fretted at the twelfth fret is sharp equated to the harmonic at the twelfth fret, the string requires more compensation and the saddle must be backed away from the fretboard. If the fretted E is flat equated to the harmonic, the string has too much compensation and the saddle will have to be adjusted towards the fretboard.
3. Adjust the saddle more or less in the proper direction by tightening or loosening the intonation screws found on the rear or front face of your bridge (Fig. 2, Fig. 3), re-tune the string and check it is intonation again.
4. Repeat these procedures until the harmonic E and fretted E are in tune with each other. Repeat for each string.
If you have a fretless instrument you must fret the twelfth fret position with the edge of a credit card, rather of your finger, to get greatest or most complete or best possible accuracy. If your fretless instrument does not have a marker that designates it is twelfth fret position, divide the instrument’s scale length in half and measure that distance from the nut down the fretboard; that is the twelfth fret position. Mark this position with some low-tack tape that will not harm the fretboard or finish, then adjust the intonation.
Once you have applied the above procedure to each string, you will have with great success intonated your instrument!
Adjusting Intonation with Fixed Saddle(s)
Adjusting the intonation of a guitar or bass that has a fixed saddle is more difficult as it is not as easy to move the saddle. If you have an instrument with a fixed saddle there are a few ways to rectify the intonation:
1. You may have the existent saddle “compensated” by a professional luthier or repair tech. This involves re-shaping the saddle to decently remunerate the strings and achieve rectify intonation.
2. You may buy a ready-made paid saddle if your instrument doesn’t already have one or it is existent saddle is other than as supposed or expected flawed. A remunerated saddle is different from a straight saddle in that portions of it is top edge will be differentially carved so they are more or less off center, causing a lot of of the strings to be further from the fretboard than others.
3. The entire bridge may be got rid of and re-set, or the bridge’s slot for the saddle may be filled and re-cut, but these are comparatively complex and pricey repairs.
4.Changing string gauges and/or altering the action may once in a while improve or rectify the intonation of an instrument with fixed saddles. These methods will be discussed in detail in the next article.
Setting intonation by moving the saddles on an instrument is a somewhat straight-forward procedure, but occasionally it may not to a complete degree rectify the intonation by itself. The next article will talk about numerous simple, inexpensive ways to improve or rectify the intonation of instruments with fixed saddles and go over a great deal of intonation troubleshooting. Thanks for reading, see you next month!
Copyright © Anthony Olinger, Xylem Handmade Basses and Guitars 2008.
Tags: bass repair, bass setups, electric guitar repair, guitar setups, intonation