Determine the relief, or bow, in the neck.![Bridge Bridge](http://www.northwestguitars.com/uploads/8/5/4/9/85494664/guitar-with-a-forward-bow-example_orig.jpg)
![Bridge Bridge](/uploads/1/2/4/6/124695438/930310204.jpg)
Nov 08, 2005 When does one know whether to adjust the string action by adjusting the trussrod or by adjusting the saddles on the bridge? The EB Frequently Asked Qu. Bridge Adjustment. You need to adjust the truss rod first, as detailed in the FAQ. Once you've got the action set, then you adjust the bridge height to suit.
- The neck of your bass must have a slight bow to play properly. If the neck were straight, you would get fret buzz, especially on notes played on the first 5 frets.
- If you have a capo, attach it at the first fret; otherwise, hold down the E-string (or B-string on a 5-string bass) at the 1st fret with your left index finger. Hold the string down at the 12th fret with your right thumb or right elbow. Use a feeler gauge to determine the largest gap between the string and the tops of the 4th through 8th frets. If the string is touching any of these frets, the neck needs more relief. If the gap between the string and any of these frets is greater than 0.020 inch (0.5 mm), then the neck needs less relief.
- Alternatively, attach a capo at the first fret or hold down the G-string at the 1st fret with your left index finger. Press the G-string down at the end of the neck with your elbow. Use a feeler gauge to measure the gap between the bottom of the string and the top of the 8th fret. If the gap exceeds 0.012 inch (0.3 mm), the neck needs less relief. If there is no gap, the neck needs more relief.
- The truss rod needs to be adjusted if inspection of the neck indicates that it needs either more or less relief.
Measure your Guitar’s Action
![Bridge Bridge](http://www.northwestguitars.com/uploads/8/5/4/9/85494664/guitar-with-a-forward-bow-example_orig.jpg)
1.Tune the guitar to pitch and ensure that your neck relief has been properly adjusted.
![Bridge Bridge](/uploads/1/2/4/6/124695438/930310204.jpg)
Some Luthiers will install a capo at the first fret in order to prevent the nut height from being a factor in their measurements. If you opt to do this, be sure that you repeat this on your next setup as well. The capo will give you a lower measurement when installed so you’ll want to be sure you have it in place at every setup once you’ve figured out your desired action.
2.Place the ruler on the 12th fret, making sure the ruler ticks are parallel to the string.
Do this so that you’re getting an accurate measurement of the gap from the top of the fret to the bottom of the low E- string.
3. Raise, lower, or leave the action.
Now you’ll need to make the decision to raise, lower or leave the action alone. Everyone’s setup preferences are a little different. For example, Jeff Beck prefers low action (3/64ths) whereas Stevie Ray Vaughn prefers a higher action (7/64ths) to accommodate his more aggressive technique. You may want to experiment and determine what’s best for your playing style.
Need more explanation? Read our article about how to measure the action of your electric guitar.