Bridge north/south placement in relation to f hole markings

Discussion in 'Setup & Repair [DB]' started by luisraulmunoz, Jun 17, 2019.

  1. Hello,

    I'm wondering if there is consensus on moving the bridge north or south to get different sound and whether this is detrimental from the officially correct position as indicated by f hole markings.

    I recently saw a lecture video by Thierry barbé on youtube (french/spanish) where he shows his instrument ( ) he shows his instrument and says he moved the bridge in order to have 103cm string length and says if you adjust sound post accordingly it sounds just as well. Visually the bridge looks way close to the fingerboard proportionately but at least in the recording seems to sound pretty great.

    Also remember reading on one of Chuck Traegers books that there is an area (relative to f-hole markings) where you can move the bridge north/south "without losing sound" though he says moving north will be brighter/stiffer and the opposite for going south.

    I like the idea of shortening string length a bit for some solo playing but Im afraid moving it north gives me a bit more stiffness which I like but loses some openness/resonance, though of course this might vary according to each instrument. Wonder if anyone has general recommendations or insights.

  2. Hoyt


    Jun 29, 2006
    Saint Charles, IL.
    There are so many factors with so many different basses, that I think it really depends on your instrument.

    To me, it’s not worth the hassle of moving/resetting the soundpost and I think any small changes would probably be almost imperceptible.

    There’s so many factors involved in a setup from the tailgut to the pegbox that it’s already sort of like hitting a moving target.

    If anything, I’d reposition the soundpost and see how it responds before I tried actually moving the bridge.
    Just my humble opinion.
  3. The only real reason to move the bridge I can think of is to cheat it up a bit to “shorten” a long mensure. Of course, then you also have to move the soundpost and start from scratch in figuring out where to place it in relation to the bridge foot.

    You also have to worry about how the new bridge placement will affect the fitting of the feet.
    Hoyt likes this.
  4. james condino

    james condino Spruce dork Supporting Member Commercial User

    Sep 30, 2007
    asheville, nc
    Move the bridge and answer your own question in five minutes......
  5. turf3


    Sep 26, 2011
    Well, in five minutes any bass player can move the bridge but many of us are not qualified to also move the sound post. If you move the bridge without bringing the post along with it, you're basically making two changes at once.
    luisraulmunoz likes this.
  6. turf3


    Sep 26, 2011
    Something else occurred to me:

    Is it possible to simulate the effect of moving the soundpost north/south with respect to the bridge, by moving the bridge south/north and leaving the post where it is? Is the effect of changing the relative position of bridge foot/soundpost greater than the effect of moving the bridge and post up and down on the top plate? Is the answer to all these questions "it depends"?
  7. If you move the bridge ½ - 1 cm upwards, in my opinion, you get a sense of how the bass would work with the sound post ½-1 cm downwards. I used to have the bridge positioned a bit higher than the "correct" place. Ofcourse it also gives other effects: slightly shorter scale length (lower tension). And at least on my bass, string height increased at bit, which was almost nescessary with my old bridge, which had been shortened through different adjustments and experiments. After a major repair, my new bridge is set up the "correct" place.
  8. Yes, I have already tried moving it of course, however I dont have the expertise to move the soundpost accordingly each time I move it and its not easy to find a good luthier where I live at the moment. Without being able to adjust the soundpost it was not possible at the moment to carry out the complete experiment as any movement will be unoptimal.

    My idea was to discuss and get a feeling for the consensus of pros or cons of moving the bridge north/south whether it is for purposes of reducing mensure or affecting sound. To listen to the different ideas regarding this specific aspect of instrument setup.

    In my case I do feel that moving north does make strings feel stiffer somewhat (which can be a welcome thing) and the low end is emphasized less (similar to what Traeger mentions).

    I see two possible reasons for moving the bridge: adjust mensure or change stiffness/tension.

    More interesting would be to test the theory of whether moving the bridge from the "ideal" place will always constitute a loss of resonance/sound.
    Or as Barbé mentions in the video it will most times work out as long as you adjust the soundpost accordingly.
  9. Eric Hochberg

    Eric Hochberg Supporting Member

    Jul 7, 2004
    I moved my bridge up 1/2" on one of my basses with no noticeable effect on the sound or feel. I'm sure my luthier adjusted the SP accordingly.
    james condino and luisraulmunoz like this.
  10. Thank you. Exactly my point.
    Hoyt likes this.
  11. I am a bit surprised that moving the bridge slightly upwards should make the feel stiffer. That was not my experience. And I can't help thinking, that the "stiffer" feeling is in fact just the effect of the strings being slightly higher from the fingerboard. But that is just my idea/theory.
  12. I understand and agree with what @Povl Carstensen says but my experience seems to match Traegers opinion. I feel the string offers more "resistance" when bowed and this is what I call "stiffer". Some what louder but less overall resonance and it's of course proportional to how much you move it to the north.
    I experienced something similar in a previous instrument. Could be related to height since the strings will be higher than before in relation to the fingrrboard but even after correcting with the adjusters there is clearly a difference in bowing feel.

    This is why I find this an interesting topic, since I saw Mr Barbé do something I considered taboo as far as setup is concerned, yet noticed the instrument sounded great nonetheless. He literally calls it (moving the bridge to get 103cm mensure) a part of his standard setup technique with any bass

    Still as always the extraneous variables are many but I think the discusion could be "all things being equal" THEN what are the general effects. Perhaps it's impossible to answer except in terms of individual instruments though.
    Last edited: Jun 24, 2019
  13. GretschWretch

    GretschWretch Supporting Member

    Dec 27, 2013
    East Central Alabama
    But how can moving the bridge north raise the strings? If the default bridge position is at the peak of the belly arch, would not moving it forward put it on a downslope and thereby have the strings nearer the fingerboard?
  14. james condino

    james condino Spruce dork Supporting Member Commercial User

    Sep 30, 2007
    asheville, nc
    Every bass responds different; there is no one definite answer. Your bass is not going to explode or forever sound like a sitar from a simple bridge or soundpost movement. Make a few small changes, see if you notice anything; make a few more. If there are no luthiers in your area, then invest in or make a set of soundpost tools, educate yourself, and then become the go to guy for your area. That is how most luthiers get started and learn.

    We are talking about simple small adjustments, not major modifications. A search on talkbass will give you all the information you need to proceed. Soundpost adjustment is not semiconductor physics. It should be basic life skills for all bass players, like changing a car tire when you get a flat. I have confidence that you and everyone here can do it. Time to leave the nest grasshopper...
    Karl Kaminski and Hoyt like this.
  15. bassmanbrent

    bassmanbrent Supporting Member

    Apr 5, 2011
    Vancouver, BC
    Every bass I've ever owned has maintained the same arching for some distance above and below the 'ideal' bridge location. Around 8" or so below the bridge and considerably more above. Put another way, the arching at the centre seam is pretty consistent for almost 2/3rds of the total belly length. If you move the bridge a 1/2" north, the bridge feet should not be any lower on the belly arching than they would be when lined up with the F hole nicks. The only thing that changes is the angle of the strings coming off the bridge. Because the bridge is now closer to the top nut, the angle of the strings coming off the bridge increases on the fingerboard side and raises the string height. I really didn't get it until a luthier showed me on my bass, but it's probably easier to just draw the two scenarios on paper. :)
    Last edited: Jun 25, 2019
  16. In short because the plane of the belly around its middle/apex is not parallel to the fingerboard.
    luisraulmunoz, DoubleMIDI and Hoyt like this.
  17. While I dont think, nor have I suggested, that soundpost adjustment is "semiconductor physics" it is something that needs to be learned properly.

    Here in Talkbass, where I searched before deciding to open a thread, I have read people say anyone should do it, I have also read luthiers mentioning that it is something you need to be careful with so as to not damage the instrument. I would prefer to learn this hands on from a luthier as I prefer not to damage my instrument, I love experimenting but not at the possible expense of my only instrument.

    Certainly anyone can understand the theory of where it should go and what should happen if you move it in one direction or another; that is not the delicate part of it.

    In any case my intention in the OP as stated before was to know IF there is a general opinion on the subject of this thread which is about moving the bridge north/south and its possible effects (certainly Chuck Traeger has his general opinion). Of course anything that can be mentioned about setup might have a different effect on different basses.
    The same is true of strings, we read eagerly the different players reviews while knowing that in our own bass the result can be quite different but that is part of the good will (and fun) conversation that enriches everyones knowledge isnt it?
  18. I made an experiment just a moment ago. I recently purchased a new bridge blank. I fitted the feet carefully and made the crown and the string slots so that the bridge is totally centered and stands correctly right in the center of the f hole notches. Currently there are no adjusters, I left them off in purpose in order to find out if a solid bridge would sound better. I was happy with the string height too, which I also left a bit higher than what I have used to.

    The bass has now been very loud with the Spiro mittels, but also sounds a little twangy and there is a little bit too much high end in the sound than I desire. Due to higher strings it has also felt that there is more tension that I would need or want. Generally typical symptons of a too tight sound post, if I can caracterise it somehow.

    Instead of tweaking the sound post I desided to move the bridge a little. I just moved it a couple of mm to the south, and a couple of mm to the bass bar side.

    As the result the G string is now a bit lower than previously, and the E is a bit higher accordingly. Moving the foot towards the bass bar seems to have added more bass to the sound, and the E string is really roaring, especially with the bow.

    Moving the bridge to the south also took a lot of the extra tension off, and the bass feels a lot easier to play.

    I’m quite surprised how huge difference such minor adjustments made to the sound and overall playability. The bridge is such little bit off-centered that you must look really carefully to even notice it. I think I just leave it as it is and enjoy.
    james condino and Earl like this.