Truss tightening makes dead spots on the neck?

Discussion in 'Hardware, Setup & Repair [BG]' started by Rockin John, Dec 9, 2004.

  1. My USA DLX Jazz 5 string seemsto have developed a couple of deads around C on the G string. I'm sure they weren't there before because, when I bought the bass a few months ago, the neck semmed unusually free of deads.

    I changed to Elites flatwounds and have tightened the truss to take up some tension over the stock Fender strings.

    Wonder whethere there's any views on this?


  2. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Well, I can't offer a scientific explanation, but here's my recent experience with a 62 RI Jazz.

    Got it out of the box, tuned it up. Action was too high and there was a dead spot at C# on the G string.

    Lowered the saddles and retuned, reset the intonation. Better action, but now there was a dead spot at the D on the G string.

    Tightened the truss rod a bit and further lowered the saddle heights, retuned, reset the intonation, and now there are no dead spots and the bass plays beautifully.

    At some point in there I also centered all of the saddles (they were pushing to the treble side), reset each string on the saddle to go exactly between the paired polepieces, and I stretched all the slack out of the string wrapped around the tuners. And I also adjusted each saddle so that the individual saddle is level rather than sloped. The strings still follow the neck radius, but each saddle is flat. Gives better sustain, the strings retain more energy, and there are fewer tuning problems this way.

    I don't know what, or which combination of things, made the dead spot go away. But it's gone.
  3. i was always lead to believe a dead spot was because the neck was resonating with the string. i've never had a problem with deadspots on any bass i've owned.
  4. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    I've heard deadspots move when you change the mass of the headstock (clamp on a heavy metal vice, for instance). It's some combination of mass, neck stiffness, string diameter and tension, string to body coupling, and behind the nut and saddle string angles. But I have no idea what the magic formula would look like.
  5. Bassic83


    Jul 26, 2004
    Texas, USSA
    Heavy metal isn't a vice, it's a way of life! ;) :D
  6. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Er, vise.
  7. It was my non-expert view about neck stiffness and dead spots that spawned the thread in the first place.

    There's no doubt these Elites require more rod adjustment than the Fender strings, so the mechanics of the neck has clearly altered. And something's definitely altered as the way the strings perform's altered, too.

    Hmmmm :confused:

  8. _Unregistered_


    Nov 3, 2004
    You're on to something. Sheep tones ("dead spots") are caused by the neck or body resonating with the string. It "steals" vibrational energy from them (inertia).

    Lyle's experience is very telling. By making subtle changes in his setup, we was able to effectively change the resonant frequency of his neck, finally arriving at a compromise that put the neck's resonance out of direct line with any specific notes on his instrument.