Adjustable Bridge Question

Discussion in 'Setup & Repair [DB]' started by joon, Jul 1, 2002.

  1. joon


    Mar 16, 2002
    Manila, Philippines

    I just got my DB set up, and now that I got it home, I was able to experiment with different string heights through the adjustable bridge. After browsing through this forum about recommended string heights, I've decided to set mine to around 5mm on the G and 8mm on the E. However, to achieve this, it seems that the adjuster on the G side has to be turned up way higher than the one on the E. To paraphrase, you can see more thread from the G adjuster than the E.

    As of now, the G is about 4-4.5mm from the edge of the FB, the E is around 10mm. I'm a bit hesitant to raise the G and lower the E more because the "adjuster differences" will be much larger.

    So my question is, would a big difference in bridge adjuster level be a problem? If so, could I just increase the height of the E string to make them equal (but string height difference will be considerable)?

    I doubt that the problem is with the FB, since it's one of the things replaced when I had the bass repaired. The thing NOT replaced, is the bridge. It was lower than usual, but its height increased when the adjusters were added.

    Hope this doesn't call for a new bridge... :eek:

  2. Kevinlee


    May 15, 2001
    Phx, AZ..USA
    I remember being told it is very important to make sure the adjusters are set at the same level. If you turn one a 1/4 turn, do the other the same way.

    I don't remember why this is so important but I'm sure there is a reason. Something to do whith top pressure or bridge alignment perhaps.

    Maybe someone else here can give you an explanation for this.

  3. Jeff Bollbach

    Jeff Bollbach Jeff Bollbach Luthier, Inc.

    Dec 12, 2001
    freeport, ny
    Joon- A disparity between adjusters can be tolerated, but only a small amount. A quarter to a half turns difference is all that could be safely done-otherwise you run the risk of cracking the bridge legs[in addition to impinging on the tone]. You really need to have your bridge height adjusted by recurving the top of the bridge.
  4. Sounds like you need the bridge reprofiled slightly to give the correct string height in relation to the fingerboard.This maybe a job for your luthier or maybe yourself given enough advise.Once the correct profile is obtained then the string to fingerboard aspect will be the same no matter the height,and you get to keep the adjusters the same height both sides.

    Damn,looks like Jeff beat me to it.
  5. olivier


    Dec 17, 1999
    Paris, France
    Joon, you just got that bass and you found it very playable, so I suggest you wait a bit and discuss this matter with your luthier before taking a final decision on string height. You don't play very often at the end of the fingerboard, so string height at that spot is not necessarily the most important parameter (but we understand that ease of playing correlates with it). Take the time to find from your own experience what kind of fine tuning you need for your set-up, instead of applying a formula from the net.
    Relax, enjoy the good life ;)
  6. joon


    Mar 16, 2002
    Manila, Philippines
    Whoa... Good that I asked this question before doing some more adjustments. As is, the adjuster difference was quite large, so I immediately increased the height on the E side. I think the major problem I have is that the bridge is too low already, so the adjuster compensates by having it high (at the G side, you can see more than 1/4" of adjuster thread). The height on the E side is better, as you can have only a little bit of adjuster height to set the E string to a good height.

    Since the adjusters should be equal in turns, I should have the contour on the E part lowered a little to match the G's. However this will heighten the adjuster settings too, particularly on the E. Will this be okay?

    Also, steve mentioned that I could adjust my bridge given proper instructions. Where can I get such instructions?

    olivier, the reason i looked at the net regarding string height is because i'd want to adjust such that it would be easy to play, at the same time still produce a good tone and sound. I guess I should be experimenting too, and given my bridge setup, my choices would be quite limited. It will do, I guess. I don't really wanna change the bridge since it's still in very good condition.

    Thanks all!
  7. arnoldschnitzer

    arnoldschnitzer AES Fine Instruments

    Feb 16, 2002
    Brewster, NY, USA
    Make sure you have at least half the adjuster thread still inside the bridge. Have the threads checked out--I'd suspect there's been some damage due to the two sides being so out of sync. Sometimes you can put a few drops of warm water in the threaded hole and the wood will spring back. Then you just run the tap through when dry and add a little graphite powder, and VIOLA! You'll have good screwing!
  8. joon


    Mar 16, 2002
    Manila, Philippines
    Good screwing is what I'd like :D

    Anyway, I just found out that raising one adjuster tends to also raise string height on the opposite end, ever-so-slightly. What I did was equalize the adjuster levels then adjusted to a satisfactory height, taking turns with each adjuster (about 1/4-1/2 turns each). End result is, I get a height that's comfortable enough for me to play, both sides of the neck. It's just not the exact 5mm-8mm height that I was expecting (more like 6mm-11mm).

    Looks like the bridge will hold up long. Thanks all!
  9. pkr2


    Apr 28, 2000
    coastal N.C.
    "Good screwing is what I'd like" [Joon]

    Are you sure that's not what you got? JK :)

  10. Alright, OK, let's settle down here. Do I have to hook up the fire hose?
  11. Nuno A.

    Nuno A. Velvet Strings Customer Service

    Jul 9, 2001
    My G side is about 5 mm and my E side is about 4...
    Still works great for 1 year now
    My luthier is a violin luthier who works part time with basses.....i found out the hard way its not perfect but thats much better than music stores.......
    Try to balance the best you can.....
    Even with a Kay bass...every adjustment i do with bridge, soundpost(i'll have a question soon for our house genious luthiers), strings....makes a huge diference on sound......

  12. Joe Taylor

    Joe Taylor

    Dec 20, 2001
    Tracy CA
    I always figured that you adjusted the bridge just high enough so that the strings did not buzz when plucked, good and hard. That way the strings are as low as you can go which = less finger presure. Jeff am I wrong.

    Individual string height is adjusted using a file on the bridge with great care and a lot of thinking first.

  13. nicklloyd

    nicklloyd Supporting Member/Luthier

    Jan 27, 2002
    Cincinnati, Ohio
    Be careful when using a file in the string-grooves of your bridge. Depth and shape are important. The groove should only be 1/3-1/2 the diameter of the string, and the shape should follow the line of the string. Often times strings break in this area; usually the groove is sqaure, deep, and the angle just behind the crown is too abrupt. SNAP! Same goes with the nut slots- not too deep, and a soft radius. Graphite from a pencil works like a champ, too. Bridges like to "creep up" towards the fingerboard, but graphite keeps them lubricated. FWIW
  14. olivier


    Dec 17, 1999
    Paris, France
    ...but you will not produce all the available volume from your instrument. I do not know the formula, if there is any (Jeff?), but with a bit more clearence/action than that you'll get more volume.
  15. Jeff Bollbach

    Jeff Bollbach Jeff Bollbach Luthier, Inc.

    Dec 12, 2001
    freeport, ny
    Olivier- no formula that I know of. These questions allcome back to just personal taste.
  16. joon


    Mar 16, 2002
    Manila, Philippines
    I dunno what that means, but by my "good screwing" I meant the adjusters, just like what arnoldschnitzer said. ;)

    I've been able to bring down the action lower, this time 5mm on G and around 10mm on E. Pushing onto the lower Es and As is hard as hell (note: I'm just beginning to play DB), but I guess that's why I need to do exercises a lot. I think I could still go lower, but too low will give me too much "growl" for my own tastes.