Setup av bass

[Mytola]

Denne guiden her, og to andre jeg har postet her, er skrevet av en bruker på Harmony Central sitt bassforum (HCBF), nemlig "Kindness". Han har veldig gode tekniske kunnskaper om både basser og forsterkere, og er en av de største bidragsyterene på HCBF når det gjelder spørsmål/svar om disse temaene.

Er det noe dere lurer på, så er det bare å fyre løs i tråden. Vil dere stille han spørsmål direkte, er det bare å registrere seg på Harmony Central-forumet og sende han en PM der.

Original URL til guiden:

http://acapella.harmony-central.com/forums...d.php?t=2067718

Kindness’s Bass Setup Thread

There are a few steps that should be taken each time an instrument is set up. Doing these steps in the proper order is critical to achieve the desired end result.

1. Tune the instrument to the pitch it will be played.

2. Set the relief.

3. Set the string heights.

4. Set the intonation.

5. Set the pickup heights.

Done. Okay, it is that easy, but here’s a better explanation.

1. Tune the instrument to the pitch it will be played.

Everything about the setup process is interactive. In order to achieve a setup that works for you in the tuning you play, you need to start the process in the same tuning. This ensures the neck is under the same tension it will be while being played. This is a good time to point out that anytime you change string tension (e.g., changing gauges, changing from flats to rounds, changing tuning), anytime the humidity changes, etc. you should reset your bass. If you keep your basses in a consistent setup, in time you will be able to feel when the setup changes even slightly.

2. Set the relief.

The first thing I notice with most people’s basses is that there is too much relief in the neck. Relief is the forward bow in the neck caused by the tension of the strings pulling the headstock of the bass towards the body of the bass. Basses play best when there is very slight relief. Not no relief, backbow is awful, but very slight forward relief. For example, Fender sets its relief at the factory to be 0.014” at the 7th fret. This means that when the E string is fretted at the first and last frets, there is 0.014” between the top of the 7th fret and the bottom of the E string. To illustrate what this minimal amount of relief looks like I took this picture:

The angle of the picture is skewed to make it look like my relief look even larger than it really is, but that just illustrates how little relief is needed.

I have chosen to use a Fender style instrument for my example because many basses set up in the exact same manner. However, there are other styles and manufacturers’ basses that use different tools and techniques, but all of the basic principles apply equally to all basses.

To set the relief, you must adjust the truss rod. A truss rod operates to counteract effects of the tension of the strings on the neck. As a result, tightening the truss rod causes the neck to bow backwards. Loosening the truss rod allows the strings to pull more forward bow into the neck. The following is a picture of a hex wrench seated in the bolt of the truss rod:

Truss rods tighten and loosen the same way a screw or a jar or any other threaded item tightens and loosen; righty tighty, lefty loosey. In the picture shown, turning the wrench clockwise tightens the truss rod to bow the neck backwards and turning the wrench counter-clockwise loosens the truss rod to allow the string tension to pull more forward bow into the neck. When tightening the nut on the truss rod, be careful not to increase the compressive force in the neck too quickly. Many people suggest a 1/4 turn on the nut at most per day. That is extremely conservative and is unlikely to ever cause you problems. If you know what you are doing, it is more conservative than necessary. If you aren't 100% positive you know exactly what is going on in the bass, stick to that guideline.

Start by setting a very slight forward relief in the neck. Fender’s starting point is a good one to use. There is nearly an infinite number of ways to measure relief, but my preferred method is to fret the E string at the first and last frets and judge the clearance around the 7th fret. You should be able to see light between the bottom of the string and the top of the 7th fret, but again, there should not be much. I know that a common recommendation is to set the relief so that the space at the 7th fret is approximately the same as the thickness of a credit card, but based on my experiences people interpret that suggestion as requiring more relief than is usually required.

Setting the relief to a measurement is okay, but the real intention of setting the relief is to make sure any buzzing occurs evenly along the entire length of the neck and is not concentrated either near the nut or towards the bridge. This enables you to set your action as low as it can go to achieve minimal or no buzzing at all points along the neck. Conversely, if the buzzing is concentrated at one end of the neck, you will have to raise the strings even higher to reduce/eliminate the buzzing.

If there is too much forward relief, the buzzing will be concentrated towards the bridge side. If the fretboard is too flat, the buzzing will be concentrated towards the nut. To check this, lower the string heights until you start to get string buzzing (or raise them if it buzzes everywhere). If the buzzing occurs equally along the length of the neck, your relief is perfect. If it buzzes in the first five frets, but not in the upper range, you need to increase the forward relief (loosen the truss rod). If it buzzes above the 12th fret, but not in the lower register, you need to decrease the forward relief (tighten the truss rod). Basically, you adjust the truss rod to chase the buzz away from the two extremes and into the middle of the fretboard.

3. Set the string heights.

This is a step that is very commonly done by eye or by feel. I’ve found that a simple measuring tool I got from StewMac enables to both precisely set the string heights and to keep my setups extremely consistent from bass to bass. http://www.stewmac.com/shop/Tools/Me...ion_Gauge.html I can’t think of a better $20 you can spend to give yourself the ability to really dial in your setups.

Here is how I use the tool to set the string heights. First, I capo the strings at the first fret. Then, I slide the measuring tool behind the E string at the 12th fret. I use the gauge to determine the distance between the top of the 12th fret and the bottom of the E string. Low action starts at about 0.060”. Medium action is around 0.080” and high action would be 0.100” and above. You can see in this picture, I’ve set the action on this bass around 0.080” (at least you would if I got a better angle on the shot):

I use the same technique across each of the strings, measuring from the top of the 12th fret to the bottom of each string. As I move towards the treble side, I slowly bring the action lower. For example, I like to set my E string at 0.080” and my G string at 0.065”. By using the tool and measuring from the top of the 12th fret all the way across the board, your string heights will follow the radius of the neck, at least to the extent you maintain consistent height. A really low setup (SA Rios, Catphish, etc.) might be 0.050” to 0.045”. That’s a light touch there.

4. Set the intonation.

This is where having a good tuner is key. I personally use the Peterson Strobostomp. Any quality strobe or virtual strobe will be perfect. Any standard tuner will work, just not as accurately.

Intonation is set to ensure the bass plays as accurately in tune as it can at all notes along the neck. The easiest way to set your intonation is to match the pitch of the fretted note at the 12th fret and the harmonic found directly above the 12th fret. If the fretted note is sharper than the harmonic, the bridge saddles should be adjusted to increase the length between the 12th fret and the bridge saddle (move the saddle backwards). If the fretted note is flatter than the harmonic, the bridge saddles should be adjusted to decrease the length between the 12th fret and the bridge saddle (move the saddle forwards). Once these notes are perfectly in unison, you can verify your intonation at other notes along the board. I like to verify at the 5th and 17th frets.

A shortcut to setting intonation (and just a good practice in general) is to set the E string and the G string first and then move the bridge saddles of the A and D string to sit in between the locations of the E and G string saddles. Then fine tune them with the tuner. Generally speaking, the bridge saddles will set up such that the heaviest gauge strings will have their saddles further backwards and the lightest gauge strings will have their saddles the furthest forward. However, taper core strings intonate with the bridge saddle further forward of where they would be with a full gauge string.

5. Set the pickup heights.

Lastly, I set the pickup heights to correspond to the string heights. I used to do so by fretting each string at the last fret and measuring the distance between the top of the pole pieces below the string and the bottom of the string. In order to make my starting point even more consistent, I've started using the string fretted at the 12th fret as my reference. I start with a distance of approximately 0.080” (5/64") and adjust from there to balance the tone with the other strings. Usually the treble side can be raised slightly. Here is a picture of how I measure:

The key is to keep the pickups close enough to get a consistently strong signal, but not close enough that the magnets in the pickups interfere with the vibrations of the strings. Also, because the string travels in a smaller range of movement towards the bridge, it is often advantageous to raise the height of the bridge pickup slightly above the height of the neck pickup to balance the outputs. In most cases, the sweet spot for pickup height is very limited. An adjustment of 1/32” can have pretty significant effects.

Håper guiden kan hjelpe folk med å få satt opp bassene sine skikkelig selv. Det er enorm forskjell på en dårlig- og en godt opsatt bass!

Igjen, er det noe dere lurer på, så er det bare å fyre løs i tråden. Vil dere stille han spørsmål direkte, er det bare å registrere seg på Harmony Central-forumet og sende han en PM der.

Ta gjerne en titt på en av de andre guidene:

Fret leveling

Matching av bassforsterker og -kabinett