So where are these "Dead Spots" I keep hearing about?

Discussion in 'Electric Instruments' started by sergiodeblanc, Jan 15, 2013.

  1. sergiodeblanc

    sergiodeblanc Get in, loser, we’re going shopping.

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    Yes, that’s what I was talking about.
     
  2. shimmilou

    shimmilou Established in 1963

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    Hmmm, maybe these so called dead spots, are from various causes, but all getting lumped together. For example, has anyone considered that some of these certain notes that don’t ring out as long as others could be caused by the pups? Particularly the magnetic pull on the strings can cause this. I have heard some notes that seem to die out quicker than others, but simply switching pups (say from bridge to neck) can get rid of the “problem”. Sometimes the strings can even become magnetized themselves. Similarly with “wolf tones”, aka “stratitis”, can be from the magnets in the pups. (we aren’t dealing with cellos, but magnetic pups in guitars)

    I certainly don’t buy the premise that these so called dead spots are inherent in all guitars made from wood. There are too many variables, such as pups, pup heights, pup position (22 vs 24), string gauge, string brand, wood types, hardware variances, etc.

    I also believe that some of the problems could be setup related, as many problems are.
     
  3. Huggy B

    Huggy B I'm feeling funky baby.

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    "Dead spots" mainly pertain to fret condition, in which worn frets that are lower than the fret(s) above it cause the notes to buzz and not give the string room enough to vibrate and produce sound. It can be caused by warped necks or bad neck joints, but this is rare and any proper fret level and setup should resolve it.

    The reason dead spots are suspected or determined around the 12th fret a lot of the time is because there are a lot of songs in E and D, and it's a place on the neck that players tend to dig in on their bends and shredding, so frets get worn there first a lot of the time. With all the songs in Amin & Cmaj, the area around the 5th & 7th frets is next in line on the fretwear sequence for a lot of guitars.
     
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  4. Tone-y

    Tone-y New Member

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    Hmmm.....Dead spots are just reality of pretty much all stringed instruments and it is due to the physics of vibration. When the frequency of the string vibration causes the body vibration to be of a similar mode shape but opposite phase, then the signals are cancelled out. This is exactly the same principle as noise cancelling headphones use. Where these dead spots occur will depend on the physical shape and material of a particular guitar. If you're lucky, they won't land directly on a particular fretted note, at least not one that you tend to let ring out.

    For instruments like Cellos, you can buy tuning weights that you attach to the strings to shift the resonance frequencies and therefore the positions of the dead spots.

    My PRS has a couple of dead spots. Most of the time they are not noticeable, and it depends on how loud I'm playing, how much gain, how new the strings are etc. But a couple of places, if I play a note and let it ring acoustically, they don't sustain as long as their neighbors.

    My Taylor 814 acoustic has some pretty bad dead spots up around the 12th fret. Notes will pretty much die off straight away.
     
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  5. Tonart

    Tonart Tone of the Art......or is that backwards?

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    Don’t know how I missed reading this post and it’s excellent reference!

    That reference itself has another reference from Fleischer and Zwicker titled “Mechanical Vibrations of Electric Guitars” which was VERY interesting.

    https://www.researchgate.net/profil...lectric-guitars.pdf?origin=publication_detail

    At last someone has bothered to delve properly and scientifically into what is effectively the electric guitar tonewood brouhahaahah.....ahahahah....hoho....haha (and I thought my jokes were bad).

    As usual (for me at least), most of the scientific paper is hard to understand due to the esoteric terminologies, but there were one or two layman passages that struck:

    Quote
    In texts on a basic level, a string is normally considered as rigidly fixed on both sides. This means that any interaction between instrument and string is excluded. However, the body of a real instrument does vibrate and influences the vibrations of the string via the end supports.
    Unquote

    Quote
    The results reveal that the neck of an electric guitar is not at all rigid. At particular frequencies it exhibits a pronounced motion.
    Unquote

    The above passages coincide with my gut feel about how an electric guitar’s body and neck can directly affect the vibration of the string, and utimately affect the tone coming out of the amplifier speaker.

    Lastly they even have a diagram showing the results of measurements of the guitar’s vibrational characteristics along the neck, one for a Les Paul and one for a Strat! Here’s a secret: they’re very different :p

    Totally cool!! Well done!!
     
    #85 Tonart, May 17, 2019
    Last edited: May 17, 2019
    bodia likes this.
  6. Tonart

    Tonart Tone of the Art......or is that backwards?

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    Been thinking about WHY ever since I noticed my Epiphone LP fitted with custom bucker pickups sounds so different plugged in compared to my 59 reissue LP with....you guessed it....custom bucker pickups.

    They sound different acoustically and plugged in. The acoustic phenomenon is simply a harbinger of the plugged in phenomenon.

    That’s why I always test an electric guitar acoustically as the foremost barometer of a magic guitar.
     
  7. Tone-y

    Tone-y New Member

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    "Dead spots in a typical electric guitar with a symmetrical headstock (such as the Les Paul) occur around 200 and 450 Hz. In a typical guitar with an asymmetrical headstock (such as the Stratocaster), the dead spots occur at slightly higher frequencies, the difference being due to torsional motion of the neck."

    Er, I don't know that I agree with this....That's way too much of a generalisation. Neck cross-section dimensions, stiffness and length would have much more impact than whether the headstock was symmetrical or not. Of course stiffness (maple/mahogany) and length (25.5/24.594") are fairly uniformly different between a Les Paul and Strat and hence their difference.
     
  8. 11top

    11top Cousin Eddie's cousin

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    I think they’re on Cold Play records.
     
  9. bodia

    bodia Authorities said.....best leave it.....unsolved

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    Concur!
     
  10. zerolight

    zerolight New Member

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    I only had this on one guitar, a PRS McCarty Rosewood, which I bought around 2004 and sold around 2008. It had a terrible dead spot around the 10th fret on the Low E string. I put it down to the Rosewood neck which felt great but I didn't like the sound of.
     
  11. Tone-y

    Tone-y New Member

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    If the dead spot is due to body resonance cancelling out string resonance, then the more resonant a body is, the greater the cancellation when the two are resonating out of phase.
     

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