Dead spots on the neck?

Discussion in 'Hardware, Setup & Repair [BG]' started by Hambone 70, Nov 11, 2016.


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  1. Hambone 70

    Hambone 70 Guest

    Sep 21, 2012
    Hi!

    After much fiddling around with the truss rod and saddles, I finally got my Aerodyne Jazz Bass to sound and play OK. Tuning and intonation are good, and action is acceptable.

    However, frets 4-6 on the G string are dead. It's almost like they're being muted when played, and although the note rings, it's a dull thud with no sustain.

    Unfortunately, there are no luthiers in my area, so it's a do-it-yourself scenario.

    It still has the original strings. Could this be the problem? It's only those three frets on the G string that are an issue, which leads me to believe it's not the strings.

    Any help appreciated!
     
  2. petrus61

    petrus61 Supporting Member

    There isn't really anything a luthier can do for an actual dead spot, AFAIK. You can attempt to add/subtract mass to the headstock by using clamps or a fat finger or adding heavier tuners. Changing strings can also help or make it worse, and is probably the most effective (short of adding mass to headstock) means to address it as going up or down a gauge or two or adding strings with more mass will change the overall resonant frequency the neck produces. Good luck!
     
  3. mark286

    mark286 Proud to be a Gold Supporting Member Gold Supporting Member

    Sep 6, 2009
    Central New Jersey
    You could try temporarily adding some weight to the headstock with a small C-clamp or using tape or rubbers bands and some coins (or something else that has some weight to it).

    If the dead spots move to another point on the neck after adding the weight to the headstock, then you know that it isn't the strings.

    EDIT: petrus61 beat me to the punch.
     
  4. JustForSport

    JustForSport

    Nov 17, 2011
    Fender style neck...
     
  5. The issue as I understand it is one of resonance. All mechanical systems resonate at a frequency that depends to a very large extent on their construction materials and methods. In fact designers go to great trouble, sometimes, to make sure their designs do not have resonances that might be destructive: aircraft; skyscrapers, cars, etc.....

    Stringed instruments are no different, so our basses all have a point of self resonance. The Fender Precision is the archetypal example, having dead spots around C to D on the G string.

    Adding stiffness to the neck (see the Warmoth neck construction details) alters the point of resonance. I have an old Columbus Precision clone with a really thick neck - no dead spots. I understand Status necks were designed to reduce resonances.

    I agree with petrus61 in that there's nothing a luthier can do. Adding mass to the headstock with one of thes clamp-on gadgets is known to work to some extent. Altering the resonant point by pushing the headstock against a wall whilst playing also apparently works!!

    For my money there are only 2 basic ways a guitar builder can combat resonance. 1) Design the instrument so that it's mechanical performance is as near even across the frequency range of interest as possible. 2) Design it so that resonances are above or below that frequency range of interest.

    My $0.02!

    Best.

    J
     
    jallenbass likes this.
  6. GIBrat51

    GIBrat51 Innocent as the day is long Supporting Member

    Mar 5, 2013
    South Bend, Indiana
    You might also try slightly - slightly - tightening or loosening the neck screws. In a couple of pretty scientific sounding articles I read on Wikipedia, there's empirical evidence that this can make a difference. And, on a couple of dead spot threads here, a few people have said that yes, trying this did make a difference. Give it a try, and let us know...:thumbsup:
     
    Zooberwerx likes this.
  7. jbrew73

    jbrew73

    Dec 24, 2006
    i had a bass with a dead spot on the E note. it seemed worse on the open e but it was on every e note on the neck. i tried new strings, setup, neck joint tightening all to no avail. i put the neck on another body (p body was swapped for a j) and the problem solved!

    i guess it isn't always a neck issue. that said i suspect a new neck would have fixed it too.
     
  8. Jazz Ad

    Jazz Ad Mi la ré sol

    3 contiguous frets sounding dead, this sounds like a setup issue rather than a dead spot. A luthier may be able to help you.
     
    RSBBass likes this.
  9. Well, it's as I said. The bass is a mechanical system that has resonance according to the materials used and method of construction. Any alteration that's made will affect the way it performs in use. Adding or removing mass, increasing or reducing stiffness, etc, etc.

    So, altering neck joint screw pressure will make a difference. Having a setup done will, too. Whether the changes are for better or for worse would remain to be seen. And changing important parts (like a neck) will make a drastically different mechanical system to the previous one.

    I suppose, sometimes, for unknown reasons, some parts don't work well together ... just like people - me and my previous guitarist, for example!!!!
     
  10. Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
    May I add...

    There is evidence to support threaded inserts to enhance coupling of the neck and body. Another trick is to slightly loosen the neck screws while tuned to pitch. This draws the neck firmly into the pocket. Re-tighten and you're good to go. IIRC, this is a G&L recommendation.

    Riis
     
    Tim Skaggs and Pilgrim like this.
  11. RSBBass

    RSBBass

    Jun 11, 2011
    NYC
    I agree with Jazz Ad. Having three contiguous notes sounds more like a setup issue. Check and see if the same notes have problems on the "D" string. While dead spots tend to be less pronounced when played on other strings, they usually are perceptible. Dead spots usually center around one note and changing the resonance by even 50 cents can have a profound imapct. I have not heard of a neck with a dead spot of a step and a half.
     
  12. Dead spots on a Precision will often be 1 note + a semitones either side. It's just how that instrument is.

    The way mechanical resonance works is very like electrical resonance. The higher the Q value the tighter resonant point. With lower Qs there is some resonance either side of the man peak value. For that matter, because there is no such thing as infinitely high Q, there is *always* some resonance reaction above and below the peak. That means there will always be some spread in the musical notes at the dead spot.

    Having said that, as RSBBass says, it may be a setup issue. Many a dead spot has been 'cured' by truss rod adjustment.

    Best

    J
     
    songwriter21 likes this.
  13. Tim Skaggs

    Tim Skaggs

    Sep 28, 2002
    There are a lot of solutions that will help a little, but none will change the laws of physics. The one sure solution is to build a bass that has a resonant frequency somewhere outside the frequency range of the instrument. You definitely won't have a dead spot caused by the resonant frequency of the instrument if the instrument can't create that resonant frequency.

    That's how use of certain materials (graphite?) and different designs (body to headstock bar?) seem to work, but don't always gain favor of the BP public.
     
  14. NoiseNinja

    NoiseNinja Experimental-psychedelic-ambient-noise-drone

    Feb 23, 2011
    Denmark
    Worst case scenario with interference resonance frequencies:

    giphy.gif

    Eventually that bridge fell apart!

    Talk about bad bridge design!

    Let that be a warning for what might happen to your neck if you keep on ignoring dead spots!
     
  15. dtripoli

    dtripoli

    Aug 15, 2010
    CA
    Dead spots, the Black Holes of the bass world. Their gravity is so strong hardly any sound escapes.
    Probably one of the oldest topics on TalkBass.
    Some basses have them and some don't. My G&L ASAT does but my beater Squier P-Bass doesn't. Go figure..
    I changed from light gauge strings to medium and it seemed to help.
    Also like so many do, after awhile you get used to it and work around it.
    I still use those three dead notes in passing but not for any sustain.
    A four string bass has 80 to 88 notes on a fretboard, of those, 3 may be duds.
     
  16. RSBBass

    RSBBass

    Jun 11, 2011
    NYC
    Wow the three dead notes that I doubted in a past post apear to happen. I have never had that problem but than again I don't play Fender.
     
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