Lowering the action

Discussion in 'Hardware, Setup & Repair [BG]' started by Tomass, Jan 19, 2006.

  1. Tomass


    Nov 1, 2005
    i know this has most likely been covered before, but my first bass which was just a practice fender squire. Nothing special but i want to make it a fretless, but the action is way to high. My bass teacher said that the action wont go any lower, he said the neck is the reason. Would playing around with the truss rod make any difference? if so how?
  2. fretlessrock

    fretlessrock Supporting Member

    Aug 8, 2002
    All the truss rod does is control the curvature, or relief, in the neck. Tighter = less relief. if you fret the E string with one hand at the 1st fret, and with the other hand at the 14th, you can observe the relief as the gap between the string and the neck at the 7th.

    The string height at the nut and the height of the saddles control the overall action height, and so does the neck angle. If you can get the neck to be reasonably flat, then you can control the action height with a combination of nut slot depth, saddle height, and neck angle. Neck angle is controlled by shimming the nek in the neck pocket at the end of the heel. Tip: a very thin shim (guitar pick, business card...) makes a big change.

    be careful with the truss rod adjustments. make any adjustments in small increments. Or better yet, find a good setup guy to inspect the bass. That should be cheap or even free if you catch the right guy at the right time.
  3. Matthew Bryson

    Matthew Bryson Guest

    Jul 30, 2001
    Good post. It should however be noted that truss rod adjustments do effect string height / action. Tightening the truss rod lowers the strings. Loosening the truss rod raises the strings. Did your teacher tell you way he feels that the neck will not take a lower action?
  4. Juneau


    Jul 15, 2004
    Dallas, TX.
    Usually the lower the action, the less relief the neck will have in order to stop buzzing. For example, I can set my action extremely low, but my neck has to be pretty much zero relief to do so. Ask your teacher to qualify his statements. Will the neck not take adjustment to get it as straight as it needs to be to lower action?

    Also of note, if you de-fret the bass, you will likely need to file down your nut slots as well to lower the action at the nut, or it will never go low enough.
  5. What is a good tool to use to file down a cheap plastic nut, and is there anything to be careful of?
  6. keyboardguy

    keyboardguy Supporting Member

    May 11, 2005
  7. Tomass


    Nov 1, 2005
    hm he said it couldnt be lowered with the saddle bridge. It buzzs after the 12th fret
  8. Bass Kahuna

    Bass Kahuna

    Dec 3, 2002
    West Lafayette, Indiana
    Luthier, Custom Builder
    It is hard to say without actually seeing the bass, but my guess based on your description of it is that there is currently too much relief (ie: forward bow) in the neck now. I find that is typical with most factory or music store setups (or complete lack thereof). As mentioned above, I like to run my necks almost dead flat, with just a slight bit of relief between the nut and the 7th fret, and with the frets shaved for a "fall away" from about the 15th fret or so to the end of the neck.

    Also, given the type of bass you said this is, I suspect that it could use a good fret shaving / levelling and redressing to get rid of any buzzing.. so... basically have a good reputable guitar tech check it out and then pay for a good fret levelling, redressing, and a complete setup including adjusting the action to where you want it . This will probably involve filing the nut grooves to the proper depth or replacing the nut if they are too low now, adjusting the truss rod for the proper amount of relief, adjusting the intonation, etc.. You teacher may be a great teacher but may not be a very good or knowledgeable guitar technician (no insult intended in any way....).
  9. Tomass


    Nov 1, 2005
    hm well i dont really want to get the frets redressed because as i said earlier i wanted to make it fretless. So your saying if i tighten the truss rod it will make it more flat?